𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Simultaneous measurement of (n, γ) and (n, fission) cross sections with the DANCE 4π BaF2 array

✍ Scribed by T.A. Bredeweg; M.M. Fowler; J.A. Becker; E.M. Bond; M.B. Chadwick; R.R.C. Clement; E.-I. Esch; T. Ethvignot; T. Granier; M. Jandel; R.A. Macri; J.M. O’Donnell; R. Reifarth; R.S. Rundberg; J.L. Ullmann; D.J. Vieira; J.B. Wilhelmy; J.M. Wouters; C.Y. Wu


Publisher
Elsevier Science
Year
2007
Tongue
English
Weight
422 KB
Volume
261
Category
Article
ISSN
0168-583X

No coin nor oath required. For personal study only.

✦ Synopsis


We have recently begun a program of high precision measurements of the key production and destruction reactions of important radiochemical diagnostic isotopes, including several isotopes of uranium, plutonium and americium. The detector for advanced neutron capture experiments (DANCE), a 4p BaF 2 array located at the Los Alamos Neutron Science Center, will be used to measure the neutron capture cross sections for most of the isotopes of interest. However, neutron capture measurements on many of the actinides are complicated by the presence of prompt c-rays arising from low energy neutron-induced fission, which competes with neutron capture to varying degrees. Previous measurements of 235 U using the DANCE array have shown that we can partially resolve capture from fission events based on total c-ray calorimetry (i.e. total c-ray energy versus c-ray multiplicity). The addition of a dedicated fission-tagging detector to the DANCE array has greatly improved our ability to separate these two competing processes. In addition to higher quality neutron capture data, the addition of a fission-tagging detector offers a means to determine the capture-to-fission ratio (r c /r f ) in a single measurement, which should reduce the effect of systematic uncertainties. We are currently using a dual parallel-plate avalanche counter (PPAC) with the target material electro-deposited directly on the center cathode foil. This design provides a high efficiency for detecting fission fragments and allows loading of pre-assembled target/detector assemblies into the neutron beam line at DANCE. Results from tests of the fission-tag detector, as well as preliminary results from measurements on 235 U and 252 Cf that utilized the fission-tag detector will be presented.


📜 SIMILAR VOLUMES


Semi-empirical systematics for the cross
✍ Junhua Luo; Fei Tuo; Fengqun Zhou; Xiangzhong Kong 📂 Article 📅 2008 🏛 Elsevier Science 🌐 English ⚖ 332 KB

Three new semi-empirical formulae for the calculation of the (n,a), (n,p) and (n,2n) cross-sections at neutron energy 14.5 MeV were obtained on the basis of experimental data measured by Lanzhou University. Derived from the statistical model with consideration of the Q-value dependence, the new form