Two detectors for (n,p) and (n,α) measurements at white neutron sources

doi:10.1016/0168-9002(95)00123-9

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

Volume 361, Issues 1–2, 1 July 1995, Pages 270-276

https://doi.org/10.1016/0168-9002(95)00123-9 Get rights and content

Abstract

We have developed two detectors for (n,p) and (n,α) cross section measurements at white neutron sources which make possible large increases in the sample size and geometric efficiency while at the same time reducing the potentially large background associated with the “gamma flash” to manageable levels. We present measurements of two (n,α) cross sections made with these detectors to energies as high as a few MeV.

References (16)

S Druyts et al.
Nucl. Phys. A
(1994)
C Wagemans et al.
Nucl. Phys. A
(1987)
Yu.P Popov et al.
JETP
(1961)
Yu.P Popov et al.
Sov. Phys.-JETP
(1961)
P.E Koehler et al.
H.P Trautvetter et al.
Z. Phys. A
(1986)
N.P Balabanov et al.
Fiz. Elem. Chastits At. Yadra
(1990)
N.P Balabanov et al.
Sov. J. Part. Nucl.
(1990)
Yu.M Gledenov et al.
Z. Phys. A
(1985)
H Weigmann et al.
Nucl. Phys. A
(1981)

There are more references available in the full text version of this article.

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Measurement of the 33S(n,α) cross-section at n_TOF(CERN): Applications to BNCT
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Citation Excerpt :
There are some discrepancies, more than a factor of 2, between experimental 33S(n,α)30Si cross-section measurements with respect to the resonance parameters available in the evaluated nuclear data files.7 Only one dedicated measurement of 33S(n,α) cross-section can be found in the literature3 since the other measurements do not provide new specific data for BNCT.4,5 Such measurement provided data from 10 keV to 1 MeV, thus the cross-section is unknown for neutron energies below 10 keV, the most important range for BNCT since neutrons are moderated by the tissue.
The main purpose of this work is to present a new (n,α) cross-section measurement for a stable isotope of sulfur, ³³S, in order to solve existing discrepancies.
³³S has been studied as a cooperating target for Boron Neutron Capture Therapy (BNCT) because of its large (n,α) cross-section in the epithermal neutron energy range, the most suitable one for BNCT. Although the most important evaluated databases, such as ENDF, do not show any resonances in the cross-section, experimental measurements which provided data from 10 keV to 1 MeV showed that the lowest-lying and strongest resonance of ³³S(n,α) cross-section occurs at 13.5 keV. Nevertheless, the set of resonance parameters that describe such resonance shows important discrepancies (more than a factor of 2) between them.
A new measurement of the ³³S(n,α)³⁰Si reaction cross-section was proposed to the ISOLDE and Neutron Time-of-Flight Experiments Committee of CERN. It was performed at n_TOF(CERN) in 2012 using MicroMegas detectors.
In this work, we will present a brief overview of the experiment as well as preliminary results of the data analysis in the neutron energy range from thermal to 100 keV. These results will be taken into account to calculate the kerma-fluence factors corresponding to ³³S in addition to ¹⁰B and those of a standard four-component ICRU tissue.
MCNP simulations of the deposited dose, including our experimental data, shows an important kerma rate enhancement at the surface of the tissue, mainly due to the presence of ³³S.
Theoretical calculations and evaluations of n + 32,33,34,36,nat.S reactions
2014, Annals of Nuclear Energy
Citation Excerpt :
The comparisons of the calculated 32S (n, α) reaction cross section and the experimental data (Schmitt, 1958; Kumabe, 1958) are given in Fig. 34. The comparisons of the calculated 33S (n, α) reaction cross section and the experimental data (Wagemans et al., 1986; Koehler et al., 1995) are given in Fig. 35. The calculated results are in agreement with the experimental data.
All cross sections of neutron induced reactions, angular distributions, energy spectra and double differential cross sections are consistently calculated and analyzed for n + ^{32,33,34,36,nat.}S reactions at incident neutron energies up to 200 MeV based on the nuclear theoretical models. Theoretical calculated results are compared with the experimental data and the evaluated results in ENDF/B-VII, JENDL-4 and TENDL-2012.
33S as a cooperative capturer for BNCT
2014, Applied Radiation and Isotopes
Citation Excerpt :
Since neutron beams of energy in the keV range are considered the optimal ones for BNCT, the knowledge of the cross-section below 10 keV is mandatory. Other 33S(n,α) cross-section measurements can be found (Koehler et al., 1995; Schatz et al., 1995) but no new specific data are provided for BCNT. Concerning the evaluations the discrepancies are even more important than for the experimental data.
³³S is a stable isotope of sulfur for which the emission of an α-particle is the dominant exit channel for neutron-induced reactions. In this work the enhancement of both the absorbed and the equivalent biologically weighted dose in a BNCT treatment with 13.5 keV neutrons, due to the presence of ³³S, has been tested by means of Monte Carlo simulations. The kerma-fluence factors for the ICRU-4 tissue have been calculated using standard weighting factors. The simulations depend crucially on the scarce ³³S(n,α)³⁰Si cross-section data. The presence of a high resonance at 13.5 keV was established by previous authors providing discrepant resonance parameters. No experimental data below 10 keV are available. All of this has motivated a proposal of experiment at the n_TOF facility at CERN. A setup was designed and tested in 2011. Some results of the successful test will be shown. The experiment is scheduled for the period November to December 2012.
Determination of Resonance Parameters and their Covariances from Neutron Induced Reaction Cross Section Data
2012, Nuclear Data Sheets
Cross section data in the resolved and unresolved resonance region are represented by nuclear reaction formalisms using parameters which are determined by fitting them to experimental data. Therefore, the quality of evaluated cross sections in the resonance region strongly depends on the experimental data used in the adjustment process and an assessment of the experimental covariance data is of primary importance in determining the accuracy of evaluated cross section data. In this contribution, uncertainty components of experimental observables resulting from total and reaction cross section experiments are quantified by identifying the metrological parameters involved in the measurement, data reduction and analysis process. In addition, different methods that can be applied to propagate the covariance of the experimental observables (i.e. transmission and reaction yields) to the covariance of the resonance parameters are discussed and compared. The methods being discussed are: conventional uncertainty propagation, Monte Carlo sampling and marginalization. It is demonstrated that the final covariance matrix of the resonance parameters not only strongly depends on the type of experimental observables used in the adjustment process, the experimental conditions and the characteristics of the resonance structure, but also on the method that is used to propagate the covariances. Finally, a special data reduction concept and format is presented, which offers the possibility to store the full covariance information of experimental data in the EXFOR library and provides the information required to perform a full covariance evaluation.
Cross-section measurements for 239Pu(n,f) and 6Li(n,α) with a lead slowing-down spectrometer
2006, Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
We present fission cross-section measurements with $\sim 10 ng$ of ²³⁹Pu performed using the LANSCE Lead Slowing-Down Spectrometer. Results of ${}^{6}{Li} (n, α)$ measurements with a sample size of $760 ng$ of ⁶Li are also reported. This technical achievement demonstrates the feasibility of measuring neutron-induced fission cross-section on samples with $10 ng$ of fissile actinides that are available on ultra-small quantities. Furthermore, results on neutron-induced alpha emission show that measurements for astrophysics purposes are feasible with the LSDS.
A compensated fission detector based on photovoltaic cells
2005, Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Standard techniques of event-by-event detection of fission may fail when operated in high $γ$ -ray or particle radiation environments. This is the case within the 800 MeV proton-driven lead slowing-down neutron spectrometer at LANSCE where standard fission detectors are found to be inoperable for microseconds to milliseconds after each proton pulse. To overcome this problem, a simple fission fragment detector based on compensated photovoltaic cells has been developed. The compensated detector has lower susceptibility to the strong $γ$ -flash and can recover much faster than an uncompensated detector. This detector is well adapted to applications involving the detection of fission in regions where high intensity $γ$ -ray and/or particle radiation fields exist.

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Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

Abstract

References (16)

Nucl. Phys. A

Nucl. Phys. A

JETP

Sov. Phys.-JETP

Z. Phys. A

Fiz. Elem. Chastits At. Yadra

Sov. J. Part. Nucl.

Z. Phys. A

Nucl. Phys. A

Cited by (24)

Measurement of the <sup>33</sup>S(n,α) cross-section at n_TOF(CERN): Applications to BNCT

Theoretical calculations and evaluations of n + <sup>32,33,34,36,nat.</sup>S reactions

<sup>33</sup>S as a cooperative capturer for BNCT

Determination of Resonance Parameters and their Covariances from Neutron Induced Reaction Cross Section Data

Cross-section measurements for <sup>239</sup>Pu(n,f) and <sup>6</sup>Li(n,α) with a lead slowing-down spectrometer

A compensated fission detector based on photovoltaic cells