C. E. Brient

Measurement of the thick-target 9Be(p, n) neutron energy spectra

Abstract The thick-target neutron energy spectra of the 9Be(p,n) reaction were measured at several angles for proton-bombarding energies of 3.0, 3.4, 3.7, 4.0, and 5.0 MeV. Time-of-flight techniques were used to determine the neutron energy spectra and to discriminate against background radiation. By using lithium-loaded glass scintillators and low proton pulse rate frequency, the neutron spectra have been determined at energies as low as 70 keV. The detectors were calibrated for efficiency using the neutron spectrum of the Al(d,n) reaction, which was accurately measured using fission chamber detectors.

A Measurement of the 27Al (d, n) Spectrum for Use in Neutron Detector Calibration

Calibration of neutron detectors for use in measurements spanning a wide range of neutron energies is normally a challenging task. Use of monoenergetic neutron beams is tedious and not convenient for certain energies. Measurements of a continuous spectrum of neutrons from the {sup 27}Al(d,n) reaction at E{sub d} = 7.44 MeV have been made with a fission chamber. This should allow rapid calibration of neutron detectors in the energy range 0.2 {le} E{sub n} {le} 14.5 MeV.

Cross sections and spectra for the sup 54 Fe and sup 56 Fe (n,xp) and (n,x. alpha. ) reactions between 8 and 15 MeV

This paper reports on cross sections and spectra for the (n,xp) and (n,x{alpha}) reactions on targets of {sup 54}Fe and {sup 56}Fe measured at 8-, 9.5-, and 11-MeV bombarding energies. The bulk of the spectra appears to be the result of compound nuclear reactions, based on their angular and emission energy dependence. A single set of level density parameters is deduced which fits not only these data but also the data recently obtained at 15 MeV. Very small (n,d) cross sections are found in this energy region.

The 59Co(n,xα) Reaction from 5 to 50 MeV

Alpha-particle production cross sections and spectra produced by neutron bombardment of 59Co are measured at 30, 60, 90, and 135 deg over the neutron energy range from 5 to 50 MeV. A source of neut...

Thick target neutron spectrum from the 9Be(p,n) reaction

The thick target spectrum from the 9Be(p,n) nuclear reaction has ben experimentally determined. The data are of use in the design of accelerator-based neutron beams for Boron Neutron Capture Therapy and Boron Neutron Capture Synovectomy due to the superior physical properties of beryllium targets compared with those made of lithium. The thick target spectrum of the reaction as a function of neutron energy and angle was measured at the Ohio University time-of-flight facility. Proton energies of 4.0, 3.7, 3.4 and 3.0 MeV were used. The neutron energy spectrum was measured using 4 lithium glass detectors at 0, 20, 40, 60, 80, and 110 degrees for 4.0 and 3.7 MeV protons, and at forward angles for 3.4 and 3.0 MeV protons. The total statistical error is less than 5 percent over most of the data set. The lithium glass detectors were calibrated using the Al(d,n) spectrum which has been accurately characterized.

Erratum: Measurement of the n-p elastic scattering angular distribution at E{sub n}=10 MeV [Phys. Rev. C 65, 014004 (2001)]

The reported data are given for the mean angles measured rather than for the central angles. The data are normalized to the most recent Evaluated Nuclear Data File evaluated angle-integrated elastic-scattering cross section and refitted with a Legendre polynomial expansion.

Measurement of the H(n,n)H Elastic Scattering Angular Distribution at En = 15 MeV

We have undertaken an experiment to measure the relative differential cross section for neutron scattering from hydrogen at a neutron energy of 15 MeV, for center‐of‐mass scattering angles from 60 degrees to 180 degrees. A total of eleven E‐ΔE telescopes were used to detect the scattered protons at laboratory angles of 0, ±12, ±24, ±36, ±48, and ±60 degrees. This experiment is intended to extend the earlier work performed by this group at 10.04 MeV. To avoid possible dead‐time problems and amplifier summing noise a unique approach to data acquisition was taken The data acquisition is based on eleven individual data‐acquisition boards, one for each detector telescope, installed in separate personal computers, each running independently. In this way, no multiplexing of the detector signals is required, and the noise associated with the summing of the signals is eliminated. Also an additional acquisition board and personal computer are used for a neutron detector, with gamma‐ray discrimination, as a neutron ...

Study of the Be(p,n) and Be(d,n) Source Reactions

We have developed lithium glass detector arrays to measure the energy spectra of neutrons below 1 MeV. The use of a calibrated neutron source spectrum allows measurement of neutron spectra from 0.070 to 14 MeV. The angular distribution and the neutron energy spectra are reported for the Be(d,n) and Be(p,n) neutron source reactions .The applications of these reactions to Boron Neutron Capture Therapy (BNCT) and neutron radiography are discussed.

Measurements of the H(n,n)H Angular Distribution at 10 MeV Neutron Energy

Relative measurements of the cross section for scattering of neutrons by protons have been made at 10 MeV neutron energy for center-of-mass neutron scattering angles from 60° to 180°. The measurements were made using the Ohio University Accelerator Laboratory’s tandem Van de Graaff accelerator with the D(d,n) reaction as the neutron source. The data are in good agreement with predictions from the phase shift analyses of Arndt, the groups of Nijmegen and Bonn, and the ENDF/B-V evaluation. The ENDF/B-Vl evaluation does not appear to have the same angular dependence as the data.

Measurement of the angular distribution of neutron-proton scattering at 10 MeV

The relative angular distribution of neutrons scattered from protons was measured at an incident neutron energy of 10 MeV at the Ohio University Accelerator Laboratory. An array of 11 detector telescopes at laboratory angles of 0 to 60 degrees was used to detect recoil protons from neutron interactions with a CH{sub 2} (polypropylene) target. Data for 7 of these telescopes were obtained with one set of electronics and are presented here. These data, from 108 to 180 degrees for the center-of-mass scattering angles, have a small slope which agrees better with angular distributions predicted by the Arndt phase shifts than with the ENDF/B-VI angular distribution.