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--> --> -->In the MeV region, however, due to the small cross sections and strong interference of background, discrepancies among different measurements and evaluations are apparent [3, 5]. Furthermore, existing measurements of the differential cross sections of the 10B(n, α)7Li reaction, as well as those of the 10B(n, α0)7Li and 10B(n, α1)7Li* reactions, are scarce. Only three measurements of angular distributions and differential cross sections (Sealock [6], Stelts [7] and Hambsch [2]) can be found in EXFOR for En ≤ 1.2 MeV and there is no data in the 1.2 MeV < En < 2.5 MeV region. Taking these factors into consideration, accurate measurements of differential and angle-integrated cross sections for the 10B(n, α)7Li reaction are demanded.
In the present work, a LPDA (Light-charged Particle Detector Array) system, which mainly consisted with a silicon detector array in a vacuum chamber, was built to study the neutron induced charged particle emission reaction at CSNS (China Spallation Neutron Source) Back-n white neutron source [8]. With 15 silicon detectors distributed from 19.2° to 160.8°, the differential and angle-integrated cross sections were obtained for the 10B(n, α)7Li reaction in the 1.0 eV ≤ En < 2.5 MeV region (67 energy points), as well as the two reaction channels, 10B(n, α0) 7Li and 10B(n, α1) 7Li*, in the 1.0 eV ≤ En < 1.0 MeV region (59 energy points). The present results have been analyzed with the resonance reaction mechanism and the level structure of the 11B compound system, and compared with existing measurements and evaluations.
2.1.Neutron source
The neutrons were produced by double bunched proton beam (1.6 GeV, ~ 20 kW) bombarding a tungsten target at CSNS Back-n white neutron source [9]. The repetition rate of the beam pulse was 25 Hz and the pulse width was ~ 41 ns. The interval between the two proton bunches was 410 ns [10]. The experiment was conducted at Endstation #1, where the length of the flight path was 57.99 m, and the neutron flux was ~ 3.5×106 n/(cm2·s). The beam spot size at Endstation #1 was determined by the apertures of the shutter and Collimator-1 [11]. The diameter of the collimation aperture of the shutter was 50 mm and that for Collimator-1 was also 50 mm in the present work. The full width at half maximum (FWHM) of the neutron beam spot was 54 – 58 mm [12]. The relative neutron intensity could be monitored by the number of protons in the beam and a Li-Si detector array mounted in the beamline. Using the single-bunch operation mode, the neutron energy spectrum was measured by a multi-layer 235U fission chamber at Endstation #2, where the length of flight was 75.76 m [13, 14]. The details of the neutron energy spectrum could be found in Refs. [8] and [14].The neutron energy spectrum and the neutron energy bins used in the present work are shown in Fig. 1. The error bar in Fig. 1 represents the uncertainty of relative neutron fluence (
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2.2.Samples
Two enriched (90%) 10B samples were prepared as shown in Fig. 2. Each 10B sample was evaporated on an aluminum sheet 50 μm in thickness. The two samples were 5.0 cm in diameter both, and 82.59 and 85.05 μg/cm2 in thickness, respectively. The two 10B samples were back-to-back mounted at one of the four sample positions of the sample holder as shown in Fig. 3. At other sample positions, two back-to-back 241Am α sources and two aluminum sheets 50 μm each in thickness were mounted. The 241Am α sources were used to calibrate the detectors and the DAQ (Data Acquisition) system, and the aluminum sheets were used for the background measurement. The angle between the normal of the samples and the neutron beam line was 60° as shown in Fig.4 (a) so that the energy loss of α-particles in the samples could be minimized.
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2.3.Detectors
The charged particles were detected by the LPDA system, which mainly consisted of a silicon detector array and a vacuum chamber as shown in Fig. 4(b). Apart from the silicon detectors, other detectors such as a gridded ionization chamber (GIC) and three ΔE-E detectors were installed and tested. Fifteen rectangular (2.0 cm × 2.5 cm) silicon detectors 500 μm in thickness could cover the emission angle of the particles from 19.2° to 160.8°, and their solid angles were (0.0123 - 0.0125) (±0.3%) sr according to Monte Carlo simulation. The distance between the center of the silicon detector and that of the 10B sample was 20.0 cm. The angle between the normal of the silicon detectors and the horizon was 16° in order to avoid shielding ΔE-E detectors.2
2.4.DAQ system
The DAQ system was designed based on PXIe platform [15]. The sampling rate of the DAQ system was 1 GHz with the resolution of 12 bits. When the signal amplitude exceeded the predefined threshold of the corresponding channel, the full signal waveform with a time window 15 μs would be recorded. In order to obtain the starting time of the signal, the original signal was filtered and differentiated, and the starting time was determined by the position of the one-tenth maximum height of the differentiated signal. The TOF of the neutron could be calculated by ${{\rm TOF}} = {T_{{\rm{event}}}} - {T_0} + \frac{L}{c},$![]() | (1) |
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2.5.Experimental process
In the experiment, the 15 silicon detectors and the DAQ system were firstly calibrated using the 241Am α sources. Then, the events from the 10B samples and the Aluminum backing sheets were measured in turns (~ 16 h for measurement foreground and ~ 8 h measurement for background for each turn). The total beam duration was ~ 357 h.
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3.1.The statistics of the events and the background subtraction
The measurement data have been sorted into two-dimensional distributions (En-Amplitude) at every detection angle. The amplitude of each event could be obtained from the recorded waveform, and the corresponding En could be calculated from its TOF. An En-Amplitude two-dimensional spectrum is shown in Fig. 6 as an example, in which the areas of α0 and α1 events, as well as the Li and Li* events, and recoil proton events are labeled. From the two-dimensional spectrum, the valid-event-area of α events could be decided. Then, the events in the valid-event-area were projected into their corresponding neutron energy bins which was described in Section 2.1.
The net events in each energy bin at each detection angle could be obtained after the background subtraction shown in Fig. 7 as an example. The normalization factor was decided by the ratio of the number of the protons in the beam during the foreground measurement over that during the background measurement. Although the background from the sample itself, such as the charge particles from the 11B(n, p) (Q = 0.23 MeV) and 10B(n, t2α) (Q = 0.32 MeV) reactions, could not be subtracted, these interferences can be ignored in En < 1 MeV region because of their fairly small cross sections [2]. In the 1.0 MeV ≤ En < 2.5 MeV region, the valid-event-area could be separated from background area because the charged particles from the background reactions with small Q-values have quite low energies. For En ≥ 2.5 MeV, the energies of the emitted background particles are high enough to interfere with the valid-event-area. Besides, the recoil protons from hydrogen adsorbed in the samples would be another notable source of the background. Therefore only the cross sections of the 10B(n, α)7Li reaction below 2.5 MeV region were obtained in the present measurement.
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3.2.The unfolding of the neutron energy bin width
The unfolding is necessary due to the influence of the width of neutron energy bin. Each event was weighted as ${w_{E,\theta }} = \frac{{{\sigma _{{E\_{\rm{bin}}{,\theta }}}}}}{{{\sigma _{{E,\theta }}}}},$![]() | (2) |
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3.3.The unfolding of the neutron energy distribution caused by the double-bunched operation mode
The interval (410 ns) of the double bunched proton beams would lead to fairly big uncertainty of the neutron energy especially in high energy region. For 0.02 MeV ≤ En < 2.5 MeV, the uncertainty of the neutron energy is 1.5% ? 17.2% which is not negligible, and the unfolding is thus needed. The details of the unfolding method could be found in Refs. [8] and [16], which will be described briefly here.At each detection angle, every event was split into two child events and each of them was weighted as
$\left\{ \begin{array}{l}{w_{{E_{n1}},\theta }} = \displaystyle \frac{{{I_{{E_{n1}}}}\sigma _{{{E_{n1}},\theta }}^{{\rm{last\_itera}}}}}{{{I_{{E_{n1}}}}\sigma _{{{E_{n1}},\theta }}^{{\rm{last\_itera}}} + {I_{{E_{n2}}}}\sigma _{{{E_{n{\rm{2}}}},\theta }}^{{\rm{last\_itera}}}}}\\{w_{{E_{n2}},\theta }} =\displaystyle \frac{{{I_{{E_{n{\rm{2}}}}}}\sigma _{{{E_{n{\rm{2}}}},\theta }}^{{\rm{last\_itera}}}}}{{{I_{{E_{n1}}}}\sigma _{{{E_{n1}},\theta }}^{{\rm{last\_itera}}} + {I_{{E_{n2}}}}\sigma _{{{E_{n{\rm{2}}}},\theta }}^{{\rm{last\_itera}}}}}\end{array} \right.,$![]() | (3) |
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3.4.The calculation of the relative differential cross sections
The relative differential cross section $\sigma _{E\_{\rm{bin,}}\theta }^{\rm re} = \frac{{{W_{E\_{\rm{bin,}}\theta }}}}{{{\varphi _{E\_{\rm{bin}}}}{\Omega _{\theta} }{N_{\rm{B}}}{\varepsilon _{E\_{\rm{bin,}}\theta }}}},$![]() | (4) |
${W_{E\_{\rm{bin,}}\theta }} = \sum\limits_{E \in E\_{\rm{bin}}} {{w_{E\_{\rm{bin,}}\theta }}} $![]() | (5) |
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3.5.The deconvolution of the spread of the detection angle
The detection angle of each silicon detector was obtained from the Monte Carlo simulation. In the simulation, the particles were assumed to be emitted isotopically from the random position in the sample and then reached the detector. According to the simulation, the spread of the detection angle for each detector was expected to be 3.8° ? 4.0° as shown in Fig. 8, which lead to the uncertainty of the detection angle. The iterative method was used to perform a correction for the spread of the detection angle.
For each neutron energy bin, the 15 measured
${\rm{cor}}\_{\sigma} _{E\_{\rm{bin,}}\theta }^{\rm re} = \sigma _{E\_{\rm{bin,}}\theta }^{\rm re}\frac{{\sigma _{E\_{\rm{bin,}}\theta }^{\rm re}}}{{C\_{\sigma} _{E\_{\rm{bin,}}\theta }^{\rm re}}}.$![]() | (6) |
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3.6.The calculation of the cross sections of the 10B(n, α)7Li reaction
It is commonly accepted that the relative differential cross section could be represented by the Legendre polynomial series $f_{E\_{\rm{bin}}}^{\rm re}(\cos (\theta )) = \sum\limits_{i = 0}^{{M}} {{A_i}} {P_i}(\cos (\theta )),$![]() | (7) |
sources of uncertainty | magnitude (%) | |
differential cross sections | angle-integrated cross sections | |
relative neutron fluence (![]() ![]() | 0.5 ? 21.4a, 0.6 ? 1.9b, 0.7 ? 0.8c | 0.5 ?21.4a, 0.6 ? 1.9b, 0.7 ? 0.8c |
unfolding of the neutron energy bin width (![]() ![]() | 0.1 ? 4.2a, 0.1 ? 7.8b, 0.3 ? 51.1c | 0.1 ? 3.8a, 0.1 ? 3.4b, 0.9 ? 7.4c |
unfolding of the expanding of neutron energy due to the double-bunched operation mode (![]() ![]() | 1.2 ? 10.9b, 2.9 ? 11.9c | 0.4 ? 1.3b, 1.0 ? 1.6c |
uncertainty of neutron energy (E_bin, lateral error) | 0.4 ? 1.4a, 0.6 ? 1.0b, 1.0 ? 1.5c | 0.4 ? 1.4a, 0.6 ? 1.0b, 1.0 ? 1.5c |
statistical error of the valid α events (![]() ![]() | 0.7 ? 3.1a, 1.0 ? 5.6b, 2.6 ? 6.9c | 0.2 ? 0.8a, 0.3 ? 1.0b, 0.8 ? 1.5c |
background subtraction (![]() ![]() | 0.1 ? 3.4a, 0.1 ? 9.0b, 0.1 ? 8.7c | < 0.6a, < 0.7b, < 0.7c |
determination the valid-even-area (![]() ![]() | 0.1 ? 3.8a, 0.3 ? 6.5b, 0.4 ? 4.4c | < 0.4a, < 0.3b, < 0.2c |
detection solid angle (Ωθ) | 0.3 | 0.3 |
number of the 10B atoms (NB) | 1.0 | 1.0 |
deconvolution of the spread of the detection angle (![]() ![]() | < 1.0 | < 0.1 |
fitting using the Legendre polynomial series (![]() ![]() | ? | 0.2 ? 1.6a, 0.6 ? 2.0b, 1.8 ? 9.5c |
normalization using the standard library (![]() ![]() | 1.3 | 1.3 |
ratios of the 10B(n, α0)7Li reaction (![]() ![]() | 2.9 ? 25.8a, 3.6 ? 36.4b | 1.7 ? 4.3a, 1.9 ? 4.6b |
ratios of the 10B(n, α1)7Li reaction (![]() ![]() | 1.0 ? 6.6a, 1.7 ? 21.6b | 0.4 ? 2.0a, 0.9 ? 4.3b |
total uncertainty of the 10B(n, α)7Li reaction (![]() ![]() ![]() ![]() | 2.8 ? 21.6a, 2.6 ? 17.3b, 4.5 ? 53.0c | 2.2 ? 21.5a, 2.1 ? 4.4b, 3.1 ? 12.4c |
total uncertainty of the 10B(n, α0)7Li reaction (![]() ![]() ![]() ![]() | 4.7 ? 26.3a, 4.7 ? 36.7b | 3.2 ? 21.6a, 2.8 ? 6.3b |
total uncertainty of the 10B(n, α1)7Li reaction (![]() ![]() ![]() ![]() | 3.1 ? 21.8a, 3.3 ? 27.7b | 2.5 ? 21.5a, 2.3 ? 5.7b |
a: Uncertainties for 1.0 eV ≤ En < 0.02 MeV. b: Uncertainties for 0.02 MeV ≤ En < 1.0 MeV. c: Uncertainties for 1.0 MeV ≤ En < 2.5 MeV. |
Table1.Sources of uncertainty and their magnitudes.
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En /MeV | ![]() ![]() | |||||
19.2° | 26.9° | 36.5° | 46.7° | 57.3° | 68.0° | |
1.00×10?6±4.2×10?9 | 4.99×104±2.1×103 | 5.00×104±2.2×103 | 5.05×104±2.2×103 | 4.96×104±2.2×103 | 5.06×104±2.1×103 | 5.00×104±2.0×103 |
1.26×10?6±5.4×10?9 | 4.13×104±1.2×103 | 4.18×104±1.2×103 | 4.22×104±1.2×103 | 4.22×104±1.2×103 | 4.24×104±1.2×103 | 4.16×104±1.2×103 |
1.58×10?6±6.8×10?9 | 3.30×104±9.7×102 | 3.24×104±9.4×102 | 3.27×104±9.4×102 | 3.27×104±9.5×102 | 3.29×104±9.5×102 | 3.29×104±9.5×102 |
2.00×10?6±8.7×10?9 | 3.07×104±1.0×103 | 3.10×104±1.0×103 | 3.08×104±1.0×103 | 3.06×104±1.0×103 | 3.13×104±1.0×103 | 3.13×104±1.0×103 |
2.51×10?6±1.1×10?8 | 2.64×104±1.2×103 | 2.65×104±1.2×103 | 2.63×104±1.2×103 | 2.67×104±1.2×103 | 2.61×104±1.2×103 | 2.61×104±1.2×103 |
3.16×10?6±1.4×10?8 | 2.94×104±1.1×103 | 2.96×104±1.1×103 | 2.92×104±1.1×103 | 3.04×104±1.1×103 | 2.98×104±1.1×103 | 3.01×104±1.1×103 |
3.98×10?6±1.8×10?8 | 2.09×104±2.5×103 | 2.16×104±2.5×103 | 2.12×104±2.5×103 | 2.13×104±2.5×103 | 2.14×104±2.5×103 | 2.09×104±2.5×103 |
5.01×10?6±2.3×10?8 | 2.07×104±1.5×103 | 2.07×104±1.5×103 | 2.06×104±1.5×103 | 2.12×104±1.6×103 | 2.07×104±1.5×103 | 2.13×104±1.6×103 |
6.31×10?6±2.9×10?8 | 2.03×104±1.1×103 | 2.11×104±1.1×103 | 2.03×104±1.1×103 | 2.03×104±1.1×103 | 2.07×104±1.1×103 | 2.05×104±1.1×103 |
7.94×10?6±3.7×10?8 | 1.70×104±3.5×103 | 1.69×104±3.5×103 | 1.70×104±3.6×103 | 1.73×104±3.6×103 | 1.75×104±3.7×103 | 1.75×104±3.7×103 |
1.00×10?5±4.7×10?8 | 1.68×104±6.5×102 | 1.61×104±6.3×102 | 1.66×104±6.4×102 | 1.64×104±6.3×102 | 1.62×104±6.3×102 | 1.65×104±6.4×102 |
1.26×10?5±6.4×10?8 | 1.45×104±1.3×103 | 1.50×104±1.3×103 | 1.44×104±1.3×103 | 1.44×104±1.3×103 | 1.45×104±1.3×103 | 1.45×104±1.3×103 |
1.58×10?5±8.6×10?8 | 1.11×104±1.7×103 | 1.14×104±1.7×103 | 1.12×104±1.7×103 | 1.13×104±1.7×103 | 1.16×104±1.7×103 | 1.12×104±1.7×103 |
2.00×10?5±1.2×10?7 | 9.50×103±1.7×103 | 9.39×103±1.7×103 | 9.45×103±1.7×103 | 9.42×103±1.7×103 | 9.46×103±1.7×103 | 9.19×103±1.7×103 |
2.51×10?5±1.6×10?7 | 1.04×104±5.1×102 | 1.03×104±5.1×102 | 1.07×104±5.2×102 | 1.05×104±5.1×102 | 1.02×104±5.0×102 | 1.03×104±5.1×102 |
3.16×10?5±2.1×10?7 | 7.29×103±1.6×103 | 7.35×103±1.6×103 | 7.40×103±1.6×103 | 7.53×103±1.6×103 | 7.49×103±1.6×103 | 7.19×103±1.6×103 |
3.98×10?5±2.7×10?7 | 7.73×103±7.1×102 | 7.36×103±6.7×102 | 7.55×103±6.9×102 | 7.45×103±6.8×102 | 7.60×103±6.9×102 | 7.49×103±6.8×102 |
5.01×10?5±3.6×10?7 | 7.24×103±5.2×102 | 7.22×103±5.2×102 | 7.00×103±5.0×102 | 6.92×103±5.0×102 | 7.25×103±5.2×102 | 7.07×103±5.1×102 |
6.31×10?5±4.8×10?7 | 5.40×103±5.4×102 | 5.42×103±5.4×102 | 5.37×103±5.4×102 | 5.34×103±5.3×102 | 5.37×103±5.4×102 | 5.08×103±5.1×102 |
7.94×10?5±6.4×10?7 | 5.40×103±5.1×102 | 5.24×103±5.0×102 | 5.16×103±4.9×102 | 5.18×103±4.9×102 | 5.00×103±4.8×102 | 5.10×103±4.9×102 |
1.00×10?4±8.4×10?7 | 4.76×103±3.7×102 | 4.78×103±3.7×102 | 4.62×103±3.6×102 | 4.80×103±3.7×102 | 4.74×103±3.7×102 | 4.55×103±3.5×102 |
1.26×10?4±1.0×10?6 | 4.48×103±4.7×102 | 4.00×103±4.3×102 | 4.23×103±4.4×102 | 4.32×103±4.5×102 | 4.41×103±4.6×102 | 4.13×103±4.3×102 |
1.58×10?4±1.3×10?6 | 3.72×103±2.9×102 | 3.72×103±2.9×102 | 3.57×103±2.8×102 | 3.62×103±2.8×102 | 3.86×103±3.0×102 | 3.61×103±2.8×102 |
2.00×10?4±1.6×10?6 | 3.37×103±2.8×102 | 3.07×103±2.6×102 | 3.08×103±2.6×102 | 3.15×103±2.6×102 | 3.14×103±2.6×102 | 3.04×103±2.5×102 |
2.51×10?4±2.0×10?6 | 3.08×103±2.7×102 | 2.87×103±2.5×102 | 2.91×103±2.5×102 | 2.93×103±2.5×102 | 2.85×103±2.5×102 | 2.86×103±2.5×102 |
3.16×10?4±2.5×10?6 | 2.78×103±1.9×102 | 2.41×103±1.7×102 | 2.47×103±1.7×102 | 2.29×103±1.6×102 | 2.55×103±1.7×102 | 2.36×103±1.6×102 |
3.98×10?4±3.1×10?6 | 2.63×103±1.8×102 | 2.49×103±1.7×102 | 2.28×103±1.6×102 | 2.40×103±1.6×102 | 2.40×103±1.7×102 | 2.27×103±1.6×102 |
5.01×10?4±3.9×10?6 | 2.28×103±1.2×102 | 2.04×103±1.1×102 | 2.04×103±1.0×102 | 2.30×103±1.1×102 | 2.19×103±1.1×102 | 2.10×103±1.1×102 |
6.31×10?4±4.8×10?6 | 1.98×103±8.4×101 | 1.74×103±7.7×101 | 1.87×103±8.1×101 | 1.81×103±7.8×101 | 1.89×103±8.2×101 | 1.73×103±7.9×101 |
7.94×10?4±6.1×10?6 | 1.79×103±9.4×101 | 1.62×103±8.8×101 | 1.67×103±8.6×101 | 1.64×103±8.2×101 | 1.60×103±8.9×101 | 1.62×103±8.4×101 |
1.00×10?3±7.7×10?6 | 1.40×103±6.4×101 | 1.40×103±6.2×101 | 1.42×103±6.1×101 | 1.49×103±6.3×101 | 1.38×103±6.0×101 | 1.25×103±5.7×101 |
1.26×10?3±9.8×10?6 | 1.24×103±4.8×101 | 1.19×103±4.6×101 | 1.20×103±4.3×101 | 1.32×103±4.4×101 | 1.24×103±4.4×101 | 1.13×103±4.6×101 |
1.58×10?3±1.3×10?5 | 1.17×103±4.3×101 | 1.08×103±5.0×101 | 1.18×103±4.0×101 | 1.11×103±4.0×101 | 1.13×103±4.0×101 | 1.08×103±4.2×101 |
2.00×10?3±1.6×10?5 | 1.06×103±3.9×101 | 1.04×103±3.8×101 | 1.03×103±3.6×101 | 1.03×103±3.6×101 | 1.04×103±3.6×101 | 9.41×102±4.0×101 |
2.51×10?3±2.1×10?5 | 8.72×102±5.7×101 | 8.82×102±5.5×101 | 9.22×102±5.6×101 | 9.55×102±5.8×101 | 9.03×102±5.8×101 | 7.98×102±5.5×101 |
3.16×10?3±2.7×10?5 | 8.74×102±3.6×101 | 8.29×102±3.3×101 | 7.96×102±3.0×101 | 8.36×102±3.1×101 | 7.91×102±3.0×101 | 7.39×102±3.5×101 |
3.98×10?3±3.6×10?5 | 7.05×102±3.1×101 | 7.71×102±3.3×101 | 7.62×102±2.8×101 | 7.54×102±2.7×101 | 7.60×102±2.8×101 | 6.85×102±3.0×101 |
5.01×10?3±4.8×10?5 | 5.90×102±2.5×101 | 6.07×102±2.5×101 | 6.39×102±2.4×101 | 6.32×102±2.3×101 | 6.21×102±2.4×101 | 5.44×102±2.5×101 |
6.31×10?3±6.4×10?5 | 6.05×102±2.5×101 | 5.94×102±2.4×101 | 5.63×102±2.3×101 | 5.91×102±2.2×101 | 5.66×102±2.2×101 | 5.53×102±2.3×101 |
7.94×10?3±8.6×10?5 | 5.11×102±2.7×101 | 5.40×102±2.5×101 | 5.06×102±2.4×101 | 5.35×102±2.3×101 | 5.29×102±2.4×101 | 4.81×102±2.4×101 |
Continued on next page |
TableA1.The differential cross sections of the 10B(n, α)7Li reaction in the laboratory reference system.
En/MeV | ![]() ![]() | ![]() ![]() | |||
133.2° | 143.5° | 153.1° | 160.8° | ||
1.00×10?6±4.2×10?9 | 5.16×104±2.1×103 | 5.16×104±2.2×103 | 5.11×104±2.2×103 | 5.12×104±2.1×103 | 6.38×105±2.7×104 |
1.26×10?6±5.4×10?9 | 4.36×104±1.2×103 | 4.29×104±1.2×103 | 4.34×104±1.2×103 | 4.30×104±1.2×103 | 5.37×105±1.4×104 |
1.58×10?6±6.8×10?9 | 3.42×104±9.9×102 | 3.33×104±9.7×102 | 3.35×104±9.9×102 | 3.39×104±1.0×103 | 4.19×105±1.1×104 |
2.00×10?6±8.7×10?9 | 3.24×104±1.1×103 | 3.21×104±1.1×103 | 3.18×104±1.0×103 | 3.17×104±1.1×103 | 3.95×105±1.2×104 |
2.51×10?6±1.1×10?8 | 2.73×104±1.3×103 | 2.68×104±1.3×103 | 2.71×104±1.3×103 | 2.71×104±1.3×103 | 3.37×105±1.5×104 |
3.16×10?6±1.4×10?8 | 3.10×104±1.1×103 | 3.07×104±1.1×103 | 3.04×104±1.1×103 | 2.96×104±1.1×103 | 3.80×105±1.3×104 |
3.98×10?6±1.8×10?8 | 2.16×104±2.6×103 | 2.26×104±2.7×103 | 2.21×104±2.6×103 | 2.21×104±2.6×103 | 2.73×105±3.2×104 |
5.01×10?6±2.3×10?8 | 2.12×104±1.6×103 | 2.15×104±1.6×103 | 2.21×104±1.6×103 | 2.11×104±1.6×103 | 2.65×105±1.9×104 |
6.31×10?6±2.9×10?8 | 2.11×104±1.1×103 | 2.11×104±1.1×103 | 2.08×104±1.1×103 | 2.09×104±1.1×103 | 2.62×105±1.4×104 |
7.94×10?6±3.7×10?8 | 1.73×104±3.6×103 | 1.78×104±3.7×103 | 1.76×104±3.7×103 | 1.76×104±3.7×103 | 2.19×105±4.6×104 |
1.00×10?5±4.7×10?8 | 1.61×104±6.3×102 | 1.68×104±6.6×102 | 1.74×104±6.8×102 | 1.72×104±6.8×102 | 2.10×105±7.5×103 |
1.26×10?5±6.4×10?8 | 1.49×104±1.3×103 | 1.49×104±1.3×103 | 1.48×104±1.3×103 | 1.43×104±1.2×103 | 1.85×105±1.6×104 |
1.58×10?5±8.6×10?8 | 1.16×104±1.7×103 | 1.18×104±1.8×103 | 1.16×104±1.7×103 | 1.13×104±1.7×103 | 1.44×105±2.1×104 |
2.00×10?5±1.2×10?7 | 9.35×103±1.7×103 | 9.67×103±1.7×103 | 9.48×103±1.7×103 | 9.19×103±1.7×103 | 1.19×105±2.1×104 |
2.51×10?5±1.6×10?7 | 1.07×104±5.3×102 | 1.07×104±5.3×102 | 1.07×104±5.3×102 | 1.06×104±5.4×102 | 1.33×105±6.0×103 |
3.16×10?5±2.1×10?7 | 7.60×103±1.6×103 | 7.66×103±1.7×103 | 7.39×103±1.6×103 | 7.35×103±1.6×103 | 9.34×104±2.0×104 |
Continued on next page |
TableA3.The differential cross sections in the laboratory reference system and angle-integrated cross sections of the 10B(n, α)7Li reaction.
2
3.7.Determination of the ratios of the cross sections of the 10B(n, α0)7Li and 10B(n, α1)7Li* reactions
After the processes presented in Sections 3.1 ? 3.6, the differential and angle-integrated cross sections of the 10B(n, α)7Li reaction have been obtained. The 10B(n, α)7Li reaction has two reaction channels which are the 10B(n, α0)7Li and 10B(n, α1)7Li* reactions. Their differential cross sections, $\sigma _{{{{E\_{\rm{bin}}{,\theta }}}}}^0 = R_{{{{E\_{\rm{bin}}{,\theta }}}}}^0{\sigma _{E\_{\rm{bin}}{,\theta }}}$![]() | (8) |
$\sigma _{{{{E\_{\rm{bin}}{,\theta }}}}}^1 = R_{{{{E\_{\rm{bin}}{,\theta }}}}}^1{\sigma _{E\_{\rm{bin}}{,\theta }}},$![]() | (9) |
Firstly, from the spectrum at the corresponding neutron energy bin and the detection angle, the valley between the two peaks of α0 and α1 could be found. If the minimum height of the valley was less than the one-tenth maximum height of the lower peak (usually α0 peak), a threshold at the least-count position would separate the two peaks directly as an example shown in Fig. 11(a). In this condition, the area of the overlap is less than 2% of the α0 or α1 peak area, and the overlap is thus negligible. Below 0.01 MeV, the α0 and α1 peaks of most spectra could be separated directly, except for the spectra of several detection angles, such as 19.2° and 160.8°.
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Secondly, if the overlap between the two peaks in the spectrum of net α events cannot be ignored, then double Gaussian functions were used to fit them. Compared with other fitting functions, such as the exponential function and the polynomial function, the double Gaussian function agrees better with the measurement spectrum. Then the area of the overlapping region would be separated by the fitting result. A typical example is shown in Fig. 11(b).
After the calculated
The differential cross sections would be fitted by the Legendre polynomial series, then the ratios of the angle-integrated cross sections of the two reaction channel would be calculated using fitting results. Finally, the angle-integrated cross sections of the 10B(n, α0)7Li and 10B(n, α1)7Li* reactions,
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En /MeV | ![]() ![]() | |||||
19.2° | 26.9° | 36.5° | 46.7° | 57.3° | 68.0° | |
1.00×10?6±4.2×10?9 | 3.21×103±1.8×102 | 3.14×103±1.7×102 | 3.09×103±1.6×102 | 3.02×103±1.6×102 | 3.15×103±1.6×102 | 3.07×103±1.5×102 |
1.26×10?6±5.4×10?9 | 2.68×103±1.4×102 | 2.51×103±1.2×102 | 2.54×103±1.2×102 | 2.46×103±1.2×102 | 2.80×103±1.3×102 | 2.72×103±1.3×102 |
1.58×10?6±6.8×10?9 | 1.93×103±1.0×102 | 2.08×103±1.0×102 | 2.07×103±1.0×102 | 2.13×103±1.1×102 | 2.07×103±1.0×102 | 2.37×103±1.1×102 |
2.00×10?6±8.7×10?9 | 1.88×103±1.1×102 | 1.92×103±1.1×102 | 1.91×103±1.0×102 | 1.87×103±1.0×102 | 1.85×103±1.0×102 | 1.92×103±1.0×102 |
2.51×10?6±1.1×10?8 | 1.69×103±1.2×102 | 1.58×103±1.1×102 | 1.66×103±1.1×102 | 1.75×103±1.1×102 | 1.74×103±1.1×102 | 1.68×103±1.1×102 |
3.16×10?6±1.4×10?8 | 1.89×103±1.3×102 | 1.87×103±1.2×102 | 1.76×103±1.2×102 | 1.88×103±1.2×102 | 1.94×103±1.3×102 | 1.89×103±1.2×102 |
3.98×10?6±1.8×10?8 | 1.54×103±2.2×102 | 1.23×103±1.8×102 | 1.33×103±1.9×102 | 1.41×103±2.0×102 | 1.31×103±1.9×102 | 1.26×103±1.8×102 |
5.01×10?6±2.3×10?8 | 1.44×103±1.3×102 | 1.25×103±1.2×102 | 1.28×103±1.2×102 | 1.29×103±1.2×102 | 1.21×103±1.1×102 | 1.46×103±1.3×102 |
6.31×10?6±2.9×10?8 | 1.30×103±1.0×102 | 1.23×103±9.6×101 | 1.19×103±9.3×101 | 1.22×103±9.5×101 | 1.28×103±9.9×101 | 1.34×103±1.0×102 |
7.94×10?6±3.7×10?8 | 1.02×103±2.2×102 | 1.12×103±2.4×102 | 9.69×102±2.1×102 | 9.98×102±2.2×102 | 1.08×103±2.4×102 | 1.25×103±2.7×102 |
1.00×10?5±4.7×10?8 | 1.15×103±8.4×101 | 9.53×102±7.3×101 | 9.30×102±7.2×101 | 1.03×103±7.7×101 | 1.06×103±7.9×101 | 1.22×103±8.5×101 |
1.26×10?5±6.4×10?8 | 9.95×102±1.1×102 | 1.04×103±1.1×102 | 9.82×102±1.0×102 | 8.62×102±9.2×101 | 9.12×102±9.7×101 | 9.31×102±9.8×101 |
1.58×10?5±8.6×10?8 | 6.91×102±1.1×102 | 6.65×102±1.1×102 | 6.02×102±9.8×101 | 6.94×102±1.1×102 | 6.79×102±1.1×102 | 7.28×102±1.2×102 |
2.00×10?5±1.2×10?7 | 7.02×102±1.4×102 | 6.60×102±1.3×102 | 5.88×102±1.1×102 | 5.38×102±1.1×102 | 6.39×102±1.2×102 | 5.92×102±1.2×102 |
2.51×10?5±1.6×10?7 | 7.07×102±6.5×101 | 7.09×102±6.5×101 | 6.89×102±6.3×101 | 6.97×102±6.3×101 | 5.97×102±5.8×101 | 7.75×102±6.8×101 |
3.16×10?5±2.1×10?7 | 4.97×102±1.1×102 | 4.14×102±9.5×101 | 5.62×102±1.3×102 | 4.39×102±1.0×102 | 4.91×102±1.1×102 | 4.43×102±1.0×102 |
3.98×10?5±2.7×10?7 | 5.22×102±6.4×101 | 4.59×102±5.7×101 | 4.70×102±5.7×101 | 4.97×102±6.0×101 | 4.34×102±5.4×101 | 4.11×102±5.2×101 |
5.01×10?5±3.6×10?7 | 5.03×102±5.0×101 | 4.81×102±4.8×101 | 4.31×102±4.3×101 | 5.11×102±5.0×101 | 4.68×102±4.6×101 | 4.40×102±4.4×101 |
6.31×10?5±4.8×10?7 | 3.49×102±4.2×101 | 3.21×102±3.9×101 | 3.36×102±4.1×101 | 3.67×102±4.3×101 | 3.24×102±3.9×101 | 3.27×102±4.0×101 |
7.94×10?5±6.4×10?7 | 3.54×102±4.3×101 | 2.89×102±3.7×101 | 3.37×102±4.1×101 | 3.16×102±3.9×101 | 3.29×102±4.0×101 | 2.66×102±3.4×101 |
1.00×10?4±8.4×10?7 | 4.25×102±4.6×101 | 3.10×102±3.5×101 | 3.01×102±3.4×101 | 2.89×102±3.2×101 | 2.51×102±2.9×101 | 2.70×102±3.1×101 |
1.26×10?4±1.0×10?6 | 3.88×102±5.3×101 | 2.56×102±4.0×101 | 3.14×102±4.4×101 | 2.62×102±3.8×101 | 2.75×102±4.0×101 | 2.58×102±3.9×101 |
1.58×10?4±1.3×10?6 | 3.26×102±3.7×101 | 1.96×102±2.6×101 | 2.22×102±2.8×101 | 2.40×102±2.9×101 | 2.09×102±2.6×101 | 2.49×102±3.0×101 |
Continued on next page |
TableA4.The differential cross sections of the 10B(n, α0)7Li reaction in the laboratory reference system.
En/MeV | ![]() ![]() | ![]() ![]() | |||
133.2° | 143.5° | 153.1° | 160.8° | ||
1.00×10?6±4.2×10?9 | 3.21×103±1.6×102 | 3.04×103±1.6×102 | 3.17×103±1.7×102 | 3.12×103±1.6×102 | 3.93×104±1.8×103 |
1.26×10?6±5.4×10?9 | 2.84×103±1.4×102 | 2.44×103±1.2×102 | 2.63×103±1.3×102 | 2.66×103±1.4×102 | 3.34×104±1.1×103 |
1.58×10?6±6.8×10?9 | 2.15×103±1.1×102 | 1.98×103±1.0×102 | 1.90×103±1.0×102 | 2.33×103±1.2×102 | 2.63×104±8.6×102 |
2.00×10?6±8.7×10?9 | 1.97×103±1.1×102 | 2.02×103±1.1×102 | 1.80×103±1.0×102 | 1.78×103±1.1×102 | 2.38×104±8.7×102 |
2.51×10?6±1.1×10?8 | 1.70×103±1.1×102 | 1.61×103±1.1×102 | 1.50×103±1.0×102 | 1.54×103±1.1×102 | 2.08×104±1.0×103 |
3.16×10?6±1.4×10?8 | 1.63×103±1.2×102 | 1.89×103±1.3×102 | 1.96×103±1.3×102 | 1.66×103±1.2×102 | 2.34×104±9.3×102 |
3.98×10?6±1.8×10?8 | 1.31×103±1.9×102 | 1.26×103±1.9×102 | 1.44×103±2.1×102 | 1.21×103±1.8×102 | 1.69×104±2.0×103 |
5.01×10?6±2.3×10?8 | 1.35×103±1.3×102 | 1.37×103±1.3×102 | 1.25×103±1.2×102 | 1.38×103±1.3×102 | 1.64×104±1.2×103 |
6.31×10?6±2.9×10?8 | 1.32×103±1.0×102 | 1.26×103±9.9×101 | 1.21×103±9.6×101 | 1.11×103±9.1×101 | 1.58×104±8.9×102 |
7.94×10?6±3.7×10?8 | 1.12×103±2.4×102 | 1.20×103±2.6×102 | 1.11×103±2.4×102 | 9.62×102±2.1×102 | 1.35×104±2.8×103 |
1.00×10?5±4.7×10?8 | 1.07×103±8.3×101 | 9.91×102±7.7×101 | 1.01×103±7.7×101 | 1.00×103±7.9×101 | 1.31×104±5.6×102 |
1.26×10?5±6.4×10?8 | 8.93×102±9.7×101 | 9.37×102±1.0×102 | 8.79×102±9.6×101 | 8.71×102±9.6×101 | 1.18×104±1.0×103 |
1.58×10?5±8.6×10?8 | 7.94×102±1.3×102 | 7.44×102±1.2×102 | 6.86×102±1.1×102 | 7.59×102±1.2×102 | 8.82×103±1.3×103 |
2.00×10?5±1.2×10?7 | 6.26×102±1.2×102 | 6.30×102±1.2×102 | 6.32×102±1.2×102 | 4.67×102±9.4×101 | 7.48×103±1.4×103 |
2.51×10?5±1.6×10?7 | 5.93×102±5.8×101 | 6.70×102±6.2×101 | 5.73×102±5.7×101 | 6.22×102±6.2×101 | 8.32×103±4.4×102 |
Continued on next page |
TableA6.The differential cross sections in the laboratory reference system and angle-integrated cross sections of the 10B(n, α0)7Li reaction.
En /MeV | ![]() ![]() | |||||
19.2° | 26.9° | 36.5° | 46.7° | 57.3° | 68.0° | |
1.00×10?6±4.2×10?9 | 4.67×104±2.4×103 | 4.69×104±2.1×103 | 4.74×104±2.1×103 | 4.65×104±2.1×103 | 4.75×104±2.0×103 | 4.70×104±2.0×103 |
1.26×10?6±5.4×10?9 | 3.86×104±1.2×103 | 3.92×104±1.2×103 | 3.97×104±1.2×103 | 3.97×104±1.2×103 | 3.96×104±1.2×103 | 3.89×104±1.2×103 |
1.58×10?6±6.8×10?9 | 3.10×104±1.2×103 | 3.03×104±9.8×102 | 3.07×104±9.9×102 | 3.06×104±9.9×102 | 3.09×104±9.9×102 | 3.05×104±9.8×102 |
2.00×10?6±8.7×10?9 | 2.88×104±1.2×103 | 2.91×104±1.1×103 | 2.89×104±1.0×103 | 2.87×104±1.1×103 | 2.94×104±1.1×103 | 2.94×104±1.1×103 |
2.51×10?6±1.1×10?8 | 2.47×104±1.2×103 | 2.49×104±1.2×103 | 2.46×104±1.2×103 | 2.50×104±1.2×103 | 2.43×104±1.2×103 | 2.44×104±1.2×103 |
3.16×10?6±1.4×10?8 | 2.75×104±1.1×103 | 2.77×104±1.1×103 | 2.75×104±1.1×103 | 2.86×104±1.2×103 | 2.78×104±1.1×103 | 2.82×104±1.1×103 |
3.98×10?6±1.8×10?8 | 1.94×104±2.4×103 | 2.04×104±2.5×103 | 1.99×104±2.4×103 | 1.99×104±2.4×103 | 2.00×104±2.4×103 | 1.97×104±2.4×103 |
5.01×10?6±2.3×10?8 | 1.93×104±1.5×103 | 1.95×104±1.5×103 | 1.94×104±1.5×103 | 1.99×104±1.5×103 | 1.95×104±1.5×103 | 1.99×104±1.5×103 |
6.31×10?6±2.9×10?8 | 1.90×104±1.1×103 | 1.99×104±1.1×103 | 1.91×104±1.1×103 | 1.91×104±1.1×103 | 1.94×104±1.1×103 | 1.92×104±1.1×103 |
7.94×10?6±3.7×10?8 | 1.59×104±3.3×103 | 1.58×104±3.3×103 | 1.61×104±3.4×103 | 1.63×104±3.4×103 | 1.64×104±3.4×103 | 1.63×104±3.4×103 |
1.00×10?5±4.7×10?8 | 1.56×104±7.5×102 | 1.52×104±6.8×102 | 1.57×104±7.0×102 | 1.54×104±6.9×102 | 1.52×104±6.8×102 | 1.52×104±6.8×102 |
1.26×10?5±6.4×10?8 | 1.35×104±1.2×103 | 1.40×104±1.2×103 | 1.34×104±1.2×103 | 1.36×104±1.2×103 | 1.36×104±1.2×103 | 1.36×104±1.2×103 |
1.58×10?5±8.6×10?8 | 1.05×104±1.6×103 | 1.08×104±1.6×103 | 1.06×104±1.6×103 | 1.06×104±1.6×103 | 1.09×104±1.6×103 | 1.05×104±1.6×103 |
2.00×10?5±1.2×10?7 | 8.80×103±1.6×103 | 8.73×103±1.6×103 | 8.87×103±1.6×103 | 8.88×103±1.6×103 | 8.82×103±1.6×103 | 8.59×103±1.6×103 |
2.51×10?5±1.6×10?7 | 9.68×103±5.5×102 | 9.58×103±5.5×102 | 9.98×103±5.6×102 | 9.78×103±5.5×102 | 9.63×103±5.5×102 | 9.52×103±5.4×102 |
3.16×10?5±2.1×10?7 | 6.80×103±1.5×103 | 6.93×103±1.5×103 | 6.84×103±1.5×103 | 7.09×103±1.5×103 | 7.00×103±1.5×103 | 6.75×103±1.5×103 |
3.98×10?5±2.7×10?7 | 7.21×103±6.9×102 | 6.90×103±6.6×102 | 7.08×103±6.8×102 | 6.95×103±6.6×102 | 7.16×103±6.8×102 | 7.07×103±6.8×102 |
5.01×10?5±3.6×10?7 | 6.73×103±5.3×102 | 6.74×103±5.1×102 | 6.57×103±5.0×102 | 6.41×103±4.9×102 | 6.78×103±5.1×102 | 6.63×103±5.0×102 |
6.31×10?5±4.8×10?7 | 5.05×103±5.2×102 | 5.10×103±5.2×102 | 5.04×103±5.2×102 | 4.97×103±5.1×102 | 5.05×103±5.2×102 | 4.76×103±4.9×102 |
7.94×10?5±6.4×10?7 | 5.04×103±5.0×102 | 4.95×103±4.9×102 | 4.82×103±4.8×102 | 4.86×103±4.8×102 | 4.67×103±4.6×102 | 4.84×103±4.8×102 |
1.00×10?4±8.4×10?7 | 4.33×103±3.7×102 | 4.48×103±3.7×102 | 4.32×103±3.6×102 | 4.51×103±3.7×102 | 4.49×103±3.7×102 | 4.28×103±3.5×102 |
1.26×10?4±1.0×10?6 | 4.09×103±4.6×102 | 3.74×103±4.3×102 | 3.91×103±4.3×102 | 4.06×103±4.5×102 | 4.13×103±4.6×102 | 3.87×103±4.3×102 |
1.58×10?4±1.3×10?6 | 3.40×103±3.0×102 | 3.52×103±3.0×102 | 3.35×103±2.8×102 | 3.38×103±2.9×102 | 3.65×103±3.1×102 | 3.36×103±2.8×102 |
2.00×10?4±1.6×10?6 | 3.06×103±2.9×102 | 2.89×103±2.8×102 | 2.87×103±2.7×102 | 2.93×103±2.7×102 | 2.97×103±2.7×102 | 2.87×103±2.7×102 |
2.51×10?4±2.0×10?6 | 2.79×103±2.6×102 | 2.70×103±2.6×102 | 2.70×103±2.6×102 | 2.70×103±2.5×102 | 2.64×103±2.5×102 | 2.64×103±2.5×102 |
3.16×10?4±2.5×10?6 | 2.54×103±2.0×102 | 2.30×103±2.0×102 | 2.33×103±1.9×102 | 2.15×103±1.8×102 | 2.37×103±1.9×102 | 2.25×103±1.9×102 |
3.98×10?4±3.1×10?6 | 2.36×103±1.9×102 | 2.34×103±1.9×102 | 2.14×103±1.8×102 | 2.26×103±1.8×102 | 2.25×103±1.8×102 | 2.10×103±1.7×102 |
5.01×10?4±3.9×10?6 | 2.06×103±1.3×102 | 1.89×103±1.3×102 | 1.91×103±1.2×102 | 2.16×103±1.3×102 | 2.05×103±1.3×102 | 1.95×103±1.2×102 |
6.31×10?4±4.8×10?6 | 1.80×103±1.0×102 | 1.65×103±1.0×102 | 1.75×103±1.0×102 | 1.70×103±9.7×101 | 1.79×103±1.0×102 | 1.60×103±9.9×101 |
7.94×10?4±6.1×10?6 | 1.62×103±1.2×102 | 1.54×103±1.1×102 | 1.58×103±1.1×102 | 1.51×103±9.9×101 | 1.50×103±1.1×102 | 1.51×103±1.0×102 |
1.00×10?3±7.7×10?6 | 1.31×103±8.3×101 | 1.33×103±8.1×101 | 1.33×103±7.8×101 | 1.38×103±7.9×101 | 1.31×103±7.8×101 | 1.15×103±7.5×101 |
1.26×10?3±9.8×10?6 | 1.20×103±7.2×101 | 1.11×103±6.7×101 | 1.12×103±6.3×101 | 1.23×103±6.4×101 | 1.17×103±6.5×101 | 1.04×103±6.5×101 |
1.58×10?3±1.3×10?5 | 1.09×103±6.2×101 | 1.02×103±6.6×101 | 1.10×103±5.7×101 | 1.03×103±5.6×101 | 1.06×103±5.7×101 | 9.97×102±5.9×101 |
2.00×10?3±1.6×10?5 | 9.89×102±5.7×101 | 9.65×102±5.5×101 | 9.43×102±5.2×101 | 9.59×102±5.2×101 | 9.42×102±5.1×101 | 8.70×102±5.6×101 |
2.51×10?3±2.1×10?5 | 8.05×102±6.9×101 | 8.27×102±6.8×101 | 8.51×102±6.7×101 | 8.87×102±6.8×101 | 8.32×102±6.8×101 | 7.62×102±6.8×101 |
3.16×10?3±2.7×10?5 | 8.28×102±5.2×101 | 7.68×102±4.9×101 | 7.37×102±4.4×101 | 7.80×102±4.5×101 | 7.37×102±4.5×101 | 6.95×102±4.9×101 |
3.98×10?3±3.6×10?5 | 6.56×102±4.5×101 | 7.24×102±4.6×101 | 7.17×102±4.2×101 | 7.02×102±4.0×101 | 6.99×102±4.1×101 | 6.39×102±4.3×101 |
5.01×10?3±4.8×10?5 | 5.57×102±3.6×101 | 5.53×102±3.5×101 | 5.87×102±3.4×101 | 5.90×102±3.3×101 | 5.79×102±3.4×101 | 4.98×102±3.5×101 |
6.31×10?3±6.4×10?5 | 5.65×102±3.7×101 | 5.54×102±3.5×101 | 5.28×102±3.3×101 | 5.50×102±3.3×101 | 5.27×102±3.3×101 | 5.10×102±3.3×101 |
Continued on next page |
TableA7.The differential cross sections of the 10B(n, α1)7Li reaction in the laboratory reference system.
En /MeV | ![]() ![]() | ![]() ![]() | |||
133.2° | 143.5° | 153.1° | 160.8° | ||
1.00×10?6±4.2×10?9 | 4.84×104±2.0×103 | 4.86×104±2.1×103 | 4.79×104±2.1×103 | 4.81×104±2.2×103 | 5.98×105±2.5×104 |
1.26×10?6±5.4×10?9 | 4.08×104±1.3×103 | 4.04×104±1.3×103 | 4.07×104±1.3×103 | 4.03×104±1.3×103 | 5.03×105±1.3×104 |
1.58×10?6±6.8×10?9 | 3.21×104±1.0×103 | 3.14×104±1.0×103 | 3.16×104±1.0×103 | 3.16×104±1.0×103 | 3.92×105±1.1×104 |
2.00×10?6±8.7×10?9 | 3.04×104±1.1×103 | 3.01×104±1.1×103 | 3.00×104±1.1×103 | 2.99×104±1.1×103 | 3.71×105±1.2×104 |
2.51×10?6±1.1×10?8 | 2.56×104±1.3×103 | 2.52×104±1.3×103 | 2.56×104±1.3×103 | 2.55×104±1.3×103 | 3.16×105±1.4×104 |
3.16×10?6±1.4×10?8 | 2.93×104±1.2×103 | 2.88×104±1.2×103 | 2.84×104±1.2×103 | 2.80×104±1.2×103 | 3.56×105±1.2×104 |
3.98×10?6±1.8×10?8 | 2.03×104±2.5×103 | 2.13×104±2.6×103 | 2.07×104±2.5×103 | 2.09×104±2.5×103 | 2.56×105±3.0×104 |
5.01×10?6±2.3×10?8 | 1.98×104±1.5×103 | 2.01×104±1.5×103 | 2.09×104±1.6×103 | 1.97×104±1.5×103 | 2.49×105±1.8×104 |
6.31×10?6±2.9×10?8 | 1.98×104±1.1×103 | 1.98×104±1.1×103 | 1.96×104±1.1×103 | 1.98×104±1.1×103 | 2.46×105±1.3×104 |
7.94×10?6±3.7×10?8 | 1.62×104±3.4×103 | 1.66×104±3.5×103 | 1.65×104±3.5×103 | 1.67×104±3.5×103 | 2.06×105±4.3×104 |
1.00×10?5±4.7×10?8 | 1.51×104±6.9×102 | 1.58×104±7.2×102 | 1.64×104±7.3×102 | 1.62×104±7.4×102 | 1.97×105±7.2×103 |
1.26×10?5±6.4×10?8 | 1.40×104±1.3×103 | 1.40×104±1.3×103 | 1.39×104±1.2×103 | 1.34×104±1.2×103 | 1.73×105±1.5×104 |
1.58×10?5±8.6×10?8 | 1.08×104±1.6×103 | 1.10×104±1.7×103 | 1.09×104±1.6×103 | 1.05×104±1.6×103 | 1.36×105±2.0×104 |
2.00×10?5±1.2×10?7 | 8.73×103±1.6×103 | 9.04×103±1.6×103 | 8.84×103±1.6×103 | 8.72×103±1.6×103 | 1.11×105±2.0×104 |
2.51×10?5±1.6×10?7 | 1.01×104±5.7×102 | 1.00×104±5.7×102 | 1.01×104±5.8×102 | 1.00×104±5.9×102 | 1.24×105±5.8×103 |
3.16×10?5±2.1×10?7 | 7.17×103±1.6×103 | 7.15×103±1.6×103 | 6.96×103±1.5×103 | 6.95×103±1.5×103 | 8.76×104±1.9×104 |
3.98×10?5±2.7×10?7 | 7.36×103±7.0×102 | 7.33×103±7.0×102 | 7.14×103±6.9×102 | 6.87×103±6.7×102 | 8.97×104±8.1×103 |
5.01×10?5±3.6×10?7 | 6.95×103±5.2×102 | 6.79×103±5.1×102 | 6.84×103±5.2×102 | 6.61×103±5.1×102 | 8.46×104±5.9×103 |
6.31×10?5±4.8×10?7 | 5.00×103±5.1×102 | 5.06×103±5.2×102 | 5.21×103±5.3×102 | 5.16×103±5.3×102 | 6.39×104±6.3×103 |
7.94×10?5±6.4×10?7 | 5.09×103±5.0×102 | 4.95×103±4.9×102 | 5.06×103±5.0×102 | 4.79×103±4.8×102 | 6.17×104±5.8×103 |
1.00×10?4±8.4×10?7 | 4.30×103±3.5×102 | 4.55×103±3.7×102 | 4.31×103±3.6×102 | 4.02×103±3.5×102 | 5.50×104±4.1×103 |
1.26×10?4±1.0×10?6 | 4.01×103±4.4×102 | 3.97×103±4.4×102 | 3.85×103±4.3×102 | 3.71×103±4.3×102 | 5.01×104±5.1×103 |
1.58×10?4±1.3×10?6 | 3.52×103±2.9×102 | 3.59×103±3.0×102 | 3.50×103±2.9×102 | 3.54×103±3.1×102 | 4.35×104±3.3×103 |
2.00×10?4±1.6×10?6 | 3.13×103±2.8×102 | 3.05×103±2.8×102 | 2.90×103±2.7×102 | 3.01×103±2.9×102 | 3.77×104±3.0×103 |
2.51×10?4±2.0×10?6 | 2.81×103±2.6×102 | 2.71×103±2.5×102 | 2.79×103±2.7×102 | 2.64×103±2.6×102 | 3.45×104±2.9×103 |
3.16×10?4±2.5×10?6 | 2.37×103±1.8×102 | 2.46×103±1.9×102 | 2.46×103±2.0×102 | 2.15×103±2.0×102 | 2.97×104±1.9×103 |
3.98×10?4±3.1×10?6 | 2.32×103±1.8×102 | 2.23×103±1.7×102 | 2.19×103±1.8×102 | 2.23×103±2.0×102 | 2.84×104±1.8×103 |
5.01×10?4±3.9×10?6 | 2.08×103±1.3×102 | 2.07×103±1.3×102 | 2.09×103±1.3×102 | 2.05×103±1.4×102 | 2.55×104±1.2×103 |
6.31×10?4±4.8×10?6 | 1.91×103±1.0×102 | 1.82×103±9.9×101 | 1.73×103±1.0×102 | 1.67×103±1.1×102 | 2.19×104±8.3×102 |
7.94×10?4±6.1×10?6 | 1.60×103±1.0×102 | 1.56×103±1.0×102 | 1.55×103±1.0×102 | 1.39×103±1.1×102 | 1.94×104±8.7×102 |
1.00×10?3±7.7×10?6 | 1.37×103±7.6×101 | 1.31×103±7.6×101 | 1.26×103±7.7×101 | 1.31×103±8.8×101 | 1.65×104±6.1×102 |
1.26×10?3±9.8×10?6 | 1.16×103±6.0×101 | 1.19×103±6.2×101 | 1.16×103±6.4×101 | 1.14×103±7.5×101 | 1.47×104±3.9×102 |
1.58×10?3±1.3×10?5 | 1.05×103±5.4×101 | 1.10×103±5.7×101 | 1.02×103±5.7×101 | 9.48×102±6.5×101 | 1.33×104±3.6×102 |
2.00×10?3±1.6×10?5 | 9.48×102±5.0×101 | 9.40×102±5.1×101 | 9.69×102±5.2×101 | 9.50×102±6.1×101 | 1.19×104±2.9×102 |
2.51×10?3±2.1×10?5 | 8.72×102±6.4×101 | 7.91×102±6.1×101 | 7.97×102±6.5×101 | 8.51×102±7.7×101 | 1.07×104±5.8×102 |
3.16×10?3±2.7×10?5 | 8.15×102±4.3×101 | 8.05×102±4.4×101 | 7.12×102±4.5×101 | 7.70×102±5.4×101 | 9.68×103±2.8×102 |
3.98×10?3±3.6×10?5 | 7.02×102±3.9×101 | 6.56×102±3.8×101 | 7.07×102±4.2×101 | 6.97×102±4.7×101 | 8.55×103±2.3×102 |
5.01×10?3±4.8×10?5 | 5.76×102±3.2×101 | 5.76×102±3.3×101 | 5.64×102±3.5×101 | 5.33×102±4.0×101 | 7.17×103±2.1×102 |
6.31×10?3±6.4×10?5 | 5.35×102±3.1×101 | 5.52×102±3.3×101 | 4.45×102±3.2×101 | 5.04×102±3.9×101 | 6.70×103±2.0×102 |
Continued on next page |
TableA9.The differential cross sections in the laboratory reference system and angle-integrated cross sections of the 10B(n, α1)7Li reaction.
4.1.Comparison of the present results with different measurements and evaluations
The present differential cross sections have been compared with existing measurement data and evaluations [3, 5]:1) For En < 0.1 MeV, the present differential cross sections of the10B(n, α)7Li, 10B(n, α0)7Li and 10B(n, α1)7Li* reactions agree well with the measurement data of Hambsch [2] (2009, 0.40 keV ? 1.20 MeV, after normalization using ENDF/B-VIII.0 data) and Stelts [7] (1979, 2 keV ? 24 keV, after normalization using the ENDF/B-VIII.0 data). The present differential cross sections of the 10B(n, α)7Li, 10B(n, α0)7Li and 10B(n, α1)7Li* reactions show that the differential cross sections are almost isotropic in the center-of-mass system and slightly forward-peaked in the laboratory system, as well as those of different evaluations.
2) In the 0.1 MeV ≤ En < 1.0 MeV region, the present differential cross sections of the 10B(n, α)7Li and 10B(n, α1)7Li* reactions agree with the measurement data of Hambsch (2009, 0.40 keV ? 0.98 MeV, after normalization using ENDF/B-VIII.0 data) [2], as well as the ENDF/B-VIII.0 and ENDF/B-VII.1 library.
For the present differential cross sections of the 10B(n, α0)7Li reaction, there are differences between the present data and the measurement data of Hambsch [2], as well as those of ENDF/B-VIII.0 and ENDF/B-VII.1 library. In this neutron energy region, compared with the measurement data of Hambsch [2] and evaluation data, the present differential cross sections are commonly higher in the forward emission angles, and lower in the backward angles. However, due to the large uncertainty of the present results of the 10B(n, α0)7Li reaction, more research is needed to clarify these differences.
Besides, the present differential cross sections of the 10B(n, α0)7Li and 10B(n, α1)7Li* don’t agree with the results of Sealock (1976, 0.20 ? 1.20 MeV) [6]. Compared with the results of Sealock [6], the uncertainty of the present differential cross sections is smaller. The average uncertainty of the results of Sealock is 22.4%, while that of the present results is 8.6% in this neutron energy region.
3) In the 1.0 MeV ≤ En < 2.5 MeV region, the discrepancies between the present differential cross sections of the 10B(n, α)7Li reaction and evaluations exist. According to the evaluations, including ENDF/B-VIII.0, ENDF/B-VII.1 and CENDL-3.1 libraries, the differential cross sections of the 10B(n, α)7Li reaction decrease monotonously with the increasing of θLab, while our present results show non-monotone decreasing trend. There is no other data in the 1.0 MeV ≤ En < 2.5 MeV region except the results of Sealock (1976, 0.20 ? 1.20 MeV), which have fairly big uncertainties (in the 1.0 MeV ≤ En < 1.20 MeV region, the average uncertainty of Sealock's results is 26.4%, while that of the present results is 8.9%) [6]. So, further researches are therefore demanded in the MeV neutron energy region.
The present cross sections have been also compared with existing measurement data from EXFOR library since 1965 and evaluations [3, 5]:
1) For the 10B(n, α)7Li reaction, the present cross sections agree well with the measurement data of Friesenhahn (1975, 2.35 keV ? 1.72 MeV) [18] for En ≤ 0.3 MeV, Sealock (1976, 0.20 ? 1.20 MeV) [6] in the 0.2 MeV ≤ En ≤ 1.2 MeV region and Bevilacqu (2017, 0.50 – 3.00 MeV) [17] in the 0.5 MeV < En < 1.0 MeV region. The present cross sections of the 10B(n, α)7Li reaction are 17.7% lower than those of Friesenhahn [18] for En > 0.3 MeV, and 12.6% higher than those of Bevilacqu [17] for En ≥ 1.0 MeV.
2) For the 10B(n, α0)7Li reaction, the present cross sections agree well with the measurement data of Macklin (1968, 0.04 ? 0.52 MeV) [19] in the 0.04 MeV ≤ En ≤ 0.1 MeV region, Sealock (1976, 0.20 ? 1.20 MeV) [6] in the 0.2 MeV ≤ En < 1.0 MeV region, and Bevilacqu (2017, 0.50 – 3.00 MeV) [17] in the 0.8 MeV ≤ En < 1.0 MeV region. The present cross sections of the 10B(n, α0)7Li reaction are 19.5% higher than those of Macklin [19] for En > 0.1 MeV and 8.1% lower than those of Bevilacqu [17] for En < 0.8 MeV.
3) For the 10B(n, α1)7Li* reaction, the present cross sections agree well with the measurement data of Schrack (1978, 3.82 keV ? 0.63 MeV) [20], Viesti (1979, 0.10 ? 2.20 MeV) [21], Sealock (1976, 0.20 ? 1.20 MeV) [6], Schrack (1993, 0.20 ? 4.06 MeV) [22] and Bevilacqu (2017, 0.50 – 3.00 MeV) [17].
Compared with different evaluations, including ENDF/B-VIII.0, ENDF/B-VII.1, JENDL-4.0, ROSFOND-2010 and CENDL-3.1 libraries, the present cross sections of the 10B(n, α0)7Li and 10B(n, α1)7Li* reactions generally agree better with ENDF/B-VIII.0 library; those of the 10B(n, α)7Li reaction agree well with ENDF/B-VIII.0 library for En ≤ 1.8 MeV, and well with ENDF/B-VII.1 library for En > 1.8 MeV [5].
2
4.2.The future experimental plan
The present results have two major sources of uncertainty: for the low neutron energy region (En < 1.0 keV), the major source is the uncertainty of the relative neutron fluence; and for the high neutron energy region (En > 2.0 MeV), the major source is the uncertainty of the unfolding of the expanding of neutron energy due to the double-bunched operation mode. As mentioned in Section 2.1, the experiment was performed at Endstation #1 (the length of flight path was 57.99 m) while the neutron spectrum was measured at Endstation #2 (the length of flight path was 75.78 m), so the actual neutron energy spectrum should be a little different between the two positions. The absolute cross sections are affected by the uncertainty of the neutron energy spectrum, while the relative angular distributions are not. The results of simulation by Fluka code was used to determine this effect [10]. According to the simulation, the deviations between the spectrum of the two position were expected to be less than 2% in the 0.3 ? 0.5 MeV region which was chosen for normalization. In the 0.1 ? 2.5 MeV region, the deviations were less than 4%. Besides, one could notice that the neutron energy spectrum has fairly big uncertainty for En < 1.0 keV because of the resonance of the cross section of the 235U(n, f) reaction below 2.5 keV region and the uncertainty of the moderation length of the neutron source. In the future, precise neutron energy spectrum at Endstation #1 should be measured.The present measurement results are limited in En < 2.5 MeV region; more work should be done in the higher neutron energy region. Besides, the peaks of α0 and α1 could not be separated for En > 1.0 MeV in the present work; thinner sample and the detectors with higher resolution should be used in the future. The unfolding of the expanding of neutron energy due to the double-bunched operation mode would introduce fairly big uncertainty for En > 2.0 MeV, so the single bunched proton beam should be used in the coming work.
The big 10B(n, α1) / 10B(n, α) cross-section ratio for the low neutron energy region could be explained by the resonance reaction mechanism and the level structure of the 11B compound system [23]. When the 10B target nucleus interacts with the low-energy neutrons (ln=0), the scattering and bound states with Jπ=7/2+ of the compound nucleus 11B would be formed, then 11B would decay to 7Li or 7Li*. The s-wave scattering state of 11B has the resonance energy of En = 0.37 MeV, and the excitation energy of 7Li* is 0.48 MeV. With the broad s-wave state (Γn(C.M.) = 0.77 MeV and Γα1(C.M.) = 0.113 MeV), the 10B(n, α1) 7Li* reaction would have large cross section in the low neutron energy region. The α0 partial width (Γα0(C.M.) = 0.001 MeV) is negligible compared to the α1 partial width, so it is very difficult for the 10B(n, α0) 7Li reaction to have the resonance with this state of 11B. Besides, the two 7/2+ s-wave states are primarily responsible for the 1/v law of the excitation function for the low neutron energy region [24].
In the neutron energy range from 0.1 MeV to 1.0 MeV, the differential cross sections of the 10B(n, α1) 7Li* reaction are forward-peaked as shown in Figs. 13 (d) ? (f) which are also mainly contributed by the two 7/2+ s-wave states of the 11B [24]. For the 10B(n, α0) 7Li reaction, the differential cross sections are backward-peaked in 0.3 ? 0.6 MeV region as shown in Fig. 12 (e), which are caused by the resonance of 5/2- p-wave state of the 11B which would occur as En ≈ 0.52 MeV. As for the excitation function, the resonance of 5/2- p-wave state would lead to a peak of the 10B(n, α0) 7Li reaction around En = 0.50 MeV. Because of the competition of the 10B(n, α0) 7Li reaction, the cross section of the 10B(n, α1) 7Li* reaction would decrease rapidly above 0.50 MeV region [2].
For 1.0 MeV ≤ En < 2.5 MeV, the differential cross sections of the 10B(n, α)7Li reaction are approximately forward-peaked in the laboratory (lab) system, while the deviations exist between the present measurements and evaluations. For example, the anomaly was observed as shown in Fig. 9 (h) around En = 1.80 MeV. It might be due to the contribution of the resonance of the 9/2- p-wave state at En = 1.83 MeV and 5/2+ or 7/2+ d-wave state at En = 1.88 MeV of 11B [25]. These resonance states would also lead to the peak of the excitation function of the 10B(n, α) 7Li reaction near En ≈ 1.80 MeV as shown in Fig. 10.
The authors are indebted to the operation crew of the CSNS Back-n white neutron source. Dr. Qiwen Fan from China Institute of Atomic Energy is appreciated for preparing the 10B samples. Prof. Zhenpeng Chen from Tsinghua University is appreciated for the beneficial discussions.
En /MeV | ![]() ![]() | ||||
78.8° | 90.3° | 101.2° | 112.0° | 122.7° | |
1.00×10?6±4.2×10?9 | 4.96×104±2.1×103 | 5.09×104±2.1×103 | 5.20×104±2.4×103 | 5.09×104±2.1×103 | 5.16×104±2.3×103 |
1.26×10?6±5.4×10?9 | 4.24×104±1.2×103 | 4.39×104±1.3×103 | 4.34×104±1.2×103 | 4.32×104±1.2×103 | 4.34×104±1.2×103 |
1.58×10?6±6.8×10?9 | 3.33×104±9.6×102 | 3.38×104±9.8×102 | 3.38×104±9.8×102 | 3.35×104±9.6×102 | 3.34×104±9.7×102 |
2.00×10?6±8.7×10?9 | 3.08×104±1.0×103 | 3.17×104±1.1×103 | 3.15×104±1.0×103 | 3.18×104±1.1×103 | 3.18×104±1.0×103 |
2.51×10?6±1.1×10?8 | 2.69×104±1.3×103 | 2.70×104±1.3×103 | 2.77×104±1.3×103 | 2.69×104±1.3×103 | 2.77×104±1.3×103 |
3.16×10?6±1.4×10?8 | 2.99×104±1.1×103 | 3.11×104±1.1×103 | 3.07×104±1.1×103 | 3.11×104±1.1×103 | 3.03×104±1.1×103 |
3.98×10?6±1.8×10?8 | 2.15×104±2.5×103 | 2.25×104±2.6×103 | 2.19×104±2.6×103 | 2.22×104±2.6×103 | 2.20×104±2.6×103 |
5.01×10?6±2.3×10?8 | 2.05×104±1.5×103 | 2.10×104±1.5×103 | 2.11×104±1.5×103 | 2.13×104±1.6×103 | 2.12×104±1.6×103 |
6.31×10?6±2.9×10?8 | 2.08×104±1.1×103 | 2.10×104±1.1×103 | 2.12×104±1.1×103 | 2.09×104±1.1×103 | 2.16×104±1.2×103 |
Continued on next page |
TableA2.The differential cross sections of the 10B(n, α)7Li reaction in the laboratory reference system.
En /MeV | ![]() ![]() | ||||
78.8° | 90.3° | 101.2° | 112.0° | 122.7° | |
1.00×10?6±4.2×10?9 | 3.08×103±1.6×102 | 3.17×103±1.7×102 | 3.02×103±1.6×102 | 3.18×103±1.6×102 | 3.20×103±1.8×102 |
1.26×10?6±5.4×10?9 | 2.79×103±1.3×102 | 2.74×103±1.3×102 | 2.65×103±1.3×102 | 2.49×103±1.2×102 | 2.92×103±1.4×102 |
1.58×10?6±6.8×10?9 | 2.15×103±1.1×102 | 1.96×103±1.0×102 | 2.14×103±1.1×102 | 1.98×103±9.9×101 | 2.16×103±1.1×102 |
2.00×10?6±8.7×10?9 | 1.97×103±1.1×102 | 1.85×103±1.0×102 | 1.84×103±1.0×102 | 1.98×103±1.1×102 | 1.90×103±1.1×102 |
2.51×10?6±1.1×10?8 | 1.64×103±1.1×102 | 1.70×103±1.1×102 | 1.57×103±1.0×102 | 1.67×103±1.1×102 | 1.80×103±1.2×102 |
3.16×10?6±1.4×10?8 | 1.95×103±1.3×102 | 2.00×103±1.3×102 | 1.89×103±1.2×102 | 1.73×103±1.1×102 | 1.94×103±1.3×102 |
3.98×10?6±1.8×10?8 | 1.35×103±2.0×102 | 1.58×103±2.2×102 | 1.31×103±1.9×102 | 1.30×103±1.8×102 | 1.35×103±2.0×102 |
5.01×10?6±2.3×10?8 | 1.25×103±1.2×102 | 1.22×103±1.1×102 | 1.29×103±1.2×102 | 1.29×103±1.2×102 | 1.28×103±1.2×102 |
6.31×10?6±2.9×10?8 | 1.25×103±9.7×101 | 1.24×103±9.5×101 | 1.37×103±1.0×102 | 1.19×103±9.2×101 | 1.35×103±1.1×102 |
7.94×10?6±3.7×10?8 | 1.01×103±2.2×102 | 1.03×103±2.3×102 | 1.17×103±2.5×102 | 9.94×102±2.2×102 | 1.05×103±2.3×102 |
1.00×10?5±4.7×10?8 | 1.04×103±7.8×101 | 1.05×103±7.6×101 | 1.02×103±7.6×101 | 1.03×103±7.5×101 | 1.10×103±8.4×101 |
1.26×10?5±6.4×10?8 | 9.36×102±1.0×102 | 9.84×102±1.0×102 | 8.60×102±9.2×101 | 9.22×102±9.7×101 | 1.07×103±1.1×102 |
1.58×10?5±8.6×10?8 | 7.08×102±1.1×102 | 7.38×102±1.2×102 | 6.15×102±1.0×102 | 7.51×102±1.2×102 | 6.81×102±1.1×102 |
2.00×10?5±1.2×10?7 | 5.65×102±1.1×102 | 5.38×102±1.0×102 | 5.75×102±1.1×102 | 5.45×102±1.1×102 | 6.38×102±1.2×102 |
2.51×10?5±1.6×10?7 | 6.21×102±6.0×101 | 6.97×102±6.2×101 | 6.01×102±5.6×101 | 6.01×102±5.5×101 | 7.75×102±7.1×101 |
3.16×10?5±2.1×10?7 | 4.54×102±1.0×102 | 4.15×102±9.4×101 | 4.40×102±1.0×102 | 4.32×102±9.8×101 | 4.89×102±1.1×102 |
3.98×10?5±2.7×10?7 | 4.07×102±5.3×101 | 5.27×102±6.1×101 | 5.02×102±5.9×101 | 4.75×102±5.6×101 | 4.90×102±6.1×101 |
5.01×10?5±3.6×10?7 | 4.11×102±4.3×101 | 4.81×102±4.7×101 | 4.72×102±4.6×101 | 4.91×102±4.7×101 | 4.35×102±4.4×101 |
6.31×10?5±4.8×10?7 | 2.79×102±3.5×101 | 3.16×102±3.8×101 | 3.69×102±4.3×101 | 3.17×102±3.8×101 | 3.49×102±4.2×101 |
7.94×10?5±6.4×10?7 | 3.04×102±3.9×101 | 2.87×102±3.5×101 | 3.46×102±4.1×101 | 2.66×102±3.3×101 | 3.34×102±4.1×101 |
1.00×10?4±8.4×10?7 | 2.68×102±3.2×101 | 2.73×102±3.0×101 | 3.08×102±3.3×101 | 3.35×102±3.5×101 | 3.17×102±3.5×101 |
1.26×10?4±1.0×10?6 | 2.53×102±3.9×101 | 2.63×102±3.6×101 | 3.42×102±4.5×101 | 2.75×102±3.8×101 | 2.35×102±3.5×101 |
1.58×10?4±1.3×10?6 | 2.30×102±3.0×101 | 1.95×102±2.3×101 | 2.70×102±3.0×101 | 1.98×102±2.4×101 | 2.26×102±2.7×101 |
2.00×10?4±1.6×10?6 | 2.29×102±3.2×101 | 1.76×102±2.3×101 | 1.77×102±2.4×101 | 1.91×102±2.4×101 | 2.12×102±2.8×101 |
2.51×10?4±2.0×10?6 | 1.78×102±2.7×101 | 1.77×102±2.2×101 | 2.06×102±2.6×101 | 1.62×102±2.1×101 | 1.91×102±2.5×101 |
3.16×10?4±2.5×10?6 | 2.28×102±3.1×101 | 1.24×102±1.7×101 | 1.25×102±1.7×101 | 1.66×102±2.0×101 | 1.74×102±2.2×101 |
3.98×10?4±3.1×10?6 | 1.82×102±2.6×101 | 1.41×102±1.7×101 | 1.46×102±1.8×101 | 1.55×102±1.8×101 | 2.03×102±2.3×101 |
5.01×10?4±3.9×10?6 | 1.26×102±1.7×101 | 1.09×102±1.2×101 | 1.29×102±1.4×101 | 1.32×102±1.4×101 | 1.27×102±1.5×101 |
6.31×10?4±4.8×10?6 | 7.23×101±1.2×101 | 8.99×101±1.0×101 | 8.78×101±1.0×101 | 1.08×102±1.2×101 | 1.23×102±1.3×101 |
7.94×10?4±6.1×10?6 | 9.27×101±1.5×101 | 1.21×102±1.3×101 | 1.01×102±1.2×101 | 1.21×102±1.3×101 | 8.99×101±1.2×101 |
1.00×10?3±7.7×10?6 | 6.06×101±1.0×101 | 9.54×101±9.8×100 | 9.75×101±1.0×101 | 9.22×101±9.7×100 | 8.81×101±1.0×101 |
1.26×10?3±9.8×10?6 | 5.13×101±9.4×100 | 8.21×101±8.7×100 | 6.73×101±7.9×100 | 1.05×102±9.9×100 | 8.41×101±9.8×100 |
1.58×10?3±1.3×10?5 | 5.74×101±9.2×100 | 7.19×101±7.6×100 | 7.16×101±7.7×100 | 5.43×101±6.4×100 | 8.05×101±8.9×100 |
2.00×10?3±1.6×10?5 | 7.68×101±1.1×101 | 7.01×101±7.3×100 | 6.22×101±6.9×100 | 6.46×101±7.0×100 | 6.33×101±7.5×100 |
2.51×10?3±2.1×10?5 | 7.30×101±1.2×101 | 6.14×101±7.6×100 | 4.63×101±6.7×100 | 7.00×101±8.3×100 | 6.19×101±8.4×100 |
3.16×10?3±2.7×10?5 | 5.88×101±9.0×100 | 5.12×101±6.2×100 | 7.31×101±7.3×100 | 5.61×101±6.2×100 | 5.25×101±6.6×100 |
3.98×10?3±3.6×10?5 | 5.01×101±8.1×100 | 5.60×101±6.1×100 | 3.76×101±4.9×100 | 3.91×101±5.0×100 | 4.42×101±5.9×100 |
5.01×10?3±4.8×10?5 | 4.41×101±6.4×100 | 4.04×101±4.6×100 | 3.94×101±4.5×100 | 4.46×101±4.8×100 | 4.24×101±5.1×100 |
6.31×10?3±6.4×10?5 | 2.28×101±5.0×100 | 3.08×101±4.0×100 | 3.82×101±4.6×100 | 4.21×101±4.8×100 | 2.98×101±4.3×100 |
Continued on next page |
TableA5.The differential cross sections of the 10B(n, α0)7Li reaction in the laboratory reference system.
En /MeV | ![]() ![]() | ||||
78.8° | 90.3° | 101.2° | 112.0° | 122.7° | |
1.00×10?6±4.2×10?9 | 4.65×104±2.0×103 | 4.77×104±2.0×103 | 4.90×104±2.3×103 | 4.77×104±2.0×103 | 4.84×104±2.2×103 |
1.26×10?6±5.4×10?9 | 3.96×104±1.2×103 | 4.12×104±1.3×103 | 4.07×104±1.3×103 | 4.07×104±1.2×103 | 4.04×104±1.3×103 |
1.58×10?6±6.8×10?9 | 3.12×104±1.0×103 | 3.19×104±1.0×103 | 3.17×104±1.0×103 | 3.15×104±1.0×103 | 3.12×104±1.0×103 |
2.00×10?6±8.7×10?9 | 2.88×104±1.0×103 | 2.98×104±1.1×103 | 2.96×104±1.1×103 | 2.99×104±1.1×103 | 2.99×104±1.1×103 |
2.51×10?6±1.1×10?8 | 2.53×104±1.2×103 | 2.53×104±1.3×103 | 2.61×104±1.3×103 | 2.52×104±1.2×103 | 2.59×104±1.3×103 |
3.16×10?6±1.4×10?8 | 2.79×104±1.1×103 | 2.91×104±1.2×103 | 2.89×104±1.2×103 | 2.93×104±1.2×103 | 2.83×104±1.2×103 |
3.98×10?6±1.8×10?8 | 2.02×104±2.5×103 | 2.09×104±2.5×103 | 2.06×104±2.5×103 | 2.09×104±2.5×103 | 2.07×104±2.5×103 |
5.01×10?6±2.3×10?8 | 1.93×104±1.5×103 | 1.98×104±1.5×103 | 1.98×104±1.5×103 | 2.00×104±1.5×103 | 2.00×104±1.5×103 |
6.31×10?6±2.9×10?8 | 1.96×104±1.1×103 | 1.98×104±1.1×103 | 1.98×104±1.1×103 | 1.97×104±1.1×103 | 2.03×104±1.2×103 |
7.94×10?6±3.7×10?8 | 1.64×104±3.4×103 | 1.64×104±3.4×103 | 1.70×104±3.6×103 | 1.66×104±3.5×103 | 1.66×104±3.5×103 |
1.00×10?5±4.7×10?8 | 1.58×104±7.0×102 | 1.58×104±6.9×102 | 1.59×104±7.0×102 | 1.55×104±6.9×102 | 1.61×104±7.3×102 |
1.26×10?5±6.4×10?8 | 1.37×104±1.2×103 | 1.36×104±1.2×103 | 1.37×104±1.2×103 | 1.41×104±1.3×103 | 1.42×104±1.3×103 |
1.58×10?5±8.6×10?8 | 1.06×104±1.6×103 | 1.09×104±1.6×103 | 1.10×104±1.6×103 | 1.09×104±1.6×103 | 1.14×104±1.7×103 |
2.00×10?5±1.2×10?7 | 8.72×103±1.6×103 | 9.24×103±1.7×103 | 8.99×103±1.6×103 | 8.68×103±1.6×103 | 9.10×103±1.7×103 |
2.51×10?5±1.6×10?7 | 1.00×104±5.7×102 | 1.01×104±5.6×102 | 1.01×104±5.6×102 | 1.00×104±5.6×102 | 9.92×103±5.7×102 |
Continued on next page |
TableA8.The differential cross sections of the 10B(n, α1)7Li reaction in the laboratory reference system.