ENTRY 31617 20080720 31293161700000001
SUBENT 31617001 20080720 31293161700100001
BIB 12 50 3161700100002
TITLE Cross-section measurement for the 10B(n,alpha)7Li 3161700100003
reaction at 4.0 and 5.0MeV 3161700100004
AUTHOR (Guohui Zhang,Li'an Guo,Rongtai Cao,Jiaguo Zhang, 3161700100005
Jinxiang Chen) 3161700100006
INSTITUTE (3CPRBJG) 3161700100007
REFERENCE (J,ARI,66,1427,2008) 3161700100008
FACILITY (VDG,3CPRBJG)Experiments were performed at the 4.5MV 3161700100009
Van de Graaff accelerator of Peking University 3161700100010
DETECTOR (IOCH)A gridded ionization chamber (GIC) was used as 3161700100011
the charged particle detector. It has the advantages 3161700100012
of high detection efficiency (close to 100%), large 3161700100013
detection solid angle (almost 2Pi), the ability of 3161700100014
particle energy and direction determination and the 3161700100015
potential of discrimination of different particles. 3161700100016
(BF3)A BF3 long counter was used as a neutron flux 3161700100017
monitor. 3161700100018
SAMPLE A 10B sample and a 238U foil were set back-to-back 3161700100019
at the common cathode. The 10B sample was evaporated 3161700100020
on a tantalum backing 4.8 cm in diameter and 50 mm 3161700100021
in thickness. The abundance of the 10B isotope was 3161700100022
94.0%. The mass of the 10B sample was 514 mu-g, and 3161700100023
the thickness was 34.7 mu-g/cm2. The mass and the 3161700100024
diameter of the 238U sample were 7.85+-0.10 mg and 3161700100025
4.50 cm, and the abundance of the 238U isotope was 3161700100026
99.999%. 3161700100027
INC-SOURCE (D-D)Neutrons were produced through the D(d,n)3He 3161700100028
reaction with a deuterium gas target. The length of 3161700100029
the gas cell was 2.0 cm and the pressure of the 3161700100030
deuterium gas was 3.0-2.87 atm with a molybdenum 3161700100031
foil window 5 mm in thickness separated from the 3161700100032
vacuum tube. The energies of the deuteron beam 3161700100033
before enter the foil were 1.77 and 2.44 MeV, and 3161700100034
the neutron energies were 4.0 and 5.0 MeV, with 3161700100035
energy spreads 0.22 and 0.16 MeV, respectively. The 3161700100036
estimated neutron fluxes on the sample were 2.1x10**5 3161700100037
and 2.5x10**5 n/s/cm2 for the above-mentioned two 3161700100038
neutron energy measurements. 3161700100039
ERR-ANALYS (ERR-T) The main sources of error of the cross-section 3161700100040
value are: 3161700100041
(ERR-1) uncertainty in background subtraction 3161700100042
(ERR-2) uncertainty in the 238U fission cross-section 3161700100043
(ERR-3) uncertainty in the 238U fission count 3161700100044
(ERR-4)uncertainty in the atom number of the 10B sample3161700100045
(ERR-5) uncertainty in the atom number of the 3161700100046
238U sample 3161700100047
Total error is about 8%. 3161700100048
MONITOR (92-U-238(N,F),,SIG) data were taken from ENDF/B-VI.8 3161700100049
STATUS (TABLE) from the abstract of ref. 3161700100050
(APRVD) Entry approved by Dr. Guohui Zhang 3161700100051
HISTORY (20080720C) SD, LV. 3161700100052
ENDBIB 50 0 3161700100053
COMMON 5 3 3161700100054
ERR-1 ERR-2 ERR-3 ERR-4 ERR-5 3161700100055
PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 3161700100056
6.5 2.5 2.5 2.0 1.3 3161700100057
ENDCOMMON 3 0 3161700100058
ENDSUBENT 57 0 3161700199999
SUBENT 31617002 20080720 31293161700200001
BIB 1 1 3161700200002
REACTION (5-B-10(N,A)3-LI-7,,SIG) 3161700200003
ENDBIB 1 0 3161700200004
NOCOMMON 0 0 3161700200005
DATA 4 2 3161700200006
EN DATA ERR-T MONIT 3161700200007
MEV MB MB MB 3161700200008
4.0 211. 17. 548.1 3161700200009
5.0 169. 14. 540.5 3161700200010
ENDDATA 4 0 3161700200011
ENDSUBENT 10 0 3161700299999
ENDENTRY 2 0 3161799999999