ENTRY 14700 20210420 14831470000000001
SUBENT 14700001 20210420 14831470000100001
BIB 10 45 1470000100002
TITLE Scattering of Slow Neutrons. II 1470000100003
AUTHOR (A.C.G.Mitchell,E.J.Murphy,M.D.Whitaker) 1470000100004
REFERENCE (J,PR,50,133,1936) 1470000100005
#doi:10.1103/PhysRev.50.133 1470000100006
REL-REF (I,,A.C.G.Mitchell+,J,PR,48,653,1935) Experimental 1470000100007
apparatus. 1470000100008
INSTITUTE (1USANYU) 1470000100009
INC-SOURCE (RA-BE) 1470000100010
DETECTOR (GEMUC) The detectors were thin sheets of the metals 1470000100011
Ag, Rh and In of dimensions 6 by 10 cm. After 1470000100012
irradiation the detectors were assayed with a 1470000100013
Geiger-Muller tube. 1470000100014
METHOD A cylindrical block of paraffin, 15 cm in diameter 1470000100015
and 17 cm high, contained a Ra-Be bulb located on the 1470000100016
axis 6 cm from the top surface. The thin detectors 1470000100017
were placed on top of the paraffin cylinder and the 1470000100018
scatterer, usually blocks of metal the same size as 1470000100019
the detector, were placed on top of the detector. In 1470000100020
some cases a sheet of Cd metal, containing 0.218 1470000100021
g/cm2, was interposed between the paraffin and the 1470000100022
detector. This served as a filter to cut out neutrons 1470000100023
of the C group. After irradiation for a given length 1470000100024
of time the detectors were placed around a 1470000100025
Geiger-Muller tube counter and the activity obtained 1470000100026
with the help of a thyratron "scale of two" recording 1470000100027
system. An activity measurement was used to derive 1470000100028
the scattering cross sections. 1470000100029
ANALYSIS Percentage of scattered neutrons was measured (n/n0). 1470000100030
This quantity is related to a combination of single 1470000100031
scattering (sigmas) and capture cross (sigmac) 1470000100032
sections as n/n0 = (N*a*sigmas/(2*N*b*(sigmas+sigmac)) 1470000100033
*[1-exp(-2*N*b*(sigmas +sigmac)*x)], where N is the 1470000100034
number of atoms/cm2 of the scatterer, and a and b 1470000100035
quantities which come in because of the solid angles 1470000100036
involved. The quantity N*(sigmas+sigmac) is the usual 1470000100037
absorption coefficient, and the factor 2 arises since 1470000100038
the neutrons traverse the scatterer twice. The 1470000100039
calculation does show, however, that the slope of the 1470000100040
curve for small thicknesses is proportional to 1470000100041
N*sigmas, and the saturation value is governed by 1470000100042
sigmas/(sigmas+sigmac). Thus the relative scattering 1470000100043
cross section can be obtained and some idea as to the 1470000100044
ratio of scattering cross section to total cross 1470000100045
section. 1470000100046
HISTORY (20210420C) BP 1470000100047
ENDBIB 45 0 1470000100048
COMMON 1 3 1470000100049
EN-DUMMY 1470000100050
EV 1470000100051
0.0253 1470000100052
ENDCOMMON 3 0 1470000100053
ENDSUBENT 52 0 1470000199999
SUBENT 14700002 20210420 14831470000200001
BIB 2 2 1470000200002
REACTION (6-C-0(N,EL)6-C-0,,SIG) 1470000200003
STATUS (TABLE) Table II, page 135. 1470000200004
ENDBIB 2 0 1470000200005
NOCOMMON 0 0 1470000200006
DATA 1 1 1470000200007
DATA 1470000200008
B 1470000200009
3.4 1470000200010
ENDDATA 3 0 1470000200011
ENDSUBENT 10 0 1470000299999
SUBENT 14700003 20210420 14831470000300001
BIB 2 2 1470000300002
REACTION (12-MG-0(N,EL)12-MG-0,,SIG) 1470000300003
STATUS (TABLE) Table II, page 135. 1470000300004
ENDBIB 2 0 1470000300005
NOCOMMON 0 0 1470000300006
DATA 1 1 1470000300007
DATA 1470000300008
B 1470000300009
3.0 1470000300010
ENDDATA 3 0 1470000300011
ENDSUBENT 10 0 1470000399999
SUBENT 14700004 20210420 14831470000400001
BIB 2 2 1470000400002
REACTION (13-AL-27(N,EL)13-AL-27,,SIG) 1470000400003
STATUS (TABLE) Table II, page 135. 1470000400004
ENDBIB 2 0 1470000400005
NOCOMMON 0 0 1470000400006
DATA 1 1 1470000400007
DATA 1470000400008
B 1470000400009
1.0 1470000400010
ENDDATA 3 0 1470000400011
ENDSUBENT 10 0 1470000499999
SUBENT 14700005 20210420 14831470000500001
BIB 2 2 1470000500002
REACTION (16-S-0(N,EL)16-S-0,,SIG) 1470000500003
STATUS (TABLE) Table II, page 135. 1470000500004
ENDBIB 2 0 1470000500005
NOCOMMON 0 0 1470000500006
DATA 1 1 1470000500007
DATA 1470000500008
B 1470000500009
0.9 1470000500010
ENDDATA 3 0 1470000500011
ENDSUBENT 10 0 1470000599999
SUBENT 14700006 20210420 14831470000600001
BIB 2 2 1470000600002
REACTION (24-CR-0(N,EL)24-CR-0,,SIG) 1470000600003
STATUS (TABLE) Table II, page 135. 1470000600004
ENDBIB 2 0 1470000600005
NOCOMMON 0 0 1470000600006
DATA 1 1 1470000600007
DATA 1470000600008
B 1470000600009
1.4 1470000600010
ENDDATA 3 0 1470000600011
ENDSUBENT 10 0 1470000699999
SUBENT 14700007 20210420 14831470000700001
BIB 2 2 1470000700002
REACTION (25-MN-55(N,EL)25-MN-55,,SIG) 1470000700003
STATUS (TABLE) Table II, page 135. 1470000700004
ENDBIB 2 0 1470000700005
NOCOMMON 0 0 1470000700006
DATA 1 1 1470000700007
DATA 1470000700008
B 1470000700009
2.2 1470000700010
ENDDATA 3 0 1470000700011
ENDSUBENT 10 0 1470000799999
SUBENT 14700008 20210420 14831470000800001
BIB 2 2 1470000800002
REACTION (26-FE-0(N,EL)26-FE-0,,SIG) 1470000800003
STATUS (TABLE) Table II, page 135. 1470000800004
ENDBIB 2 0 1470000800005
NOCOMMON 0 0 1470000800006
DATA 1 1 1470000800007
DATA 1470000800008
B 1470000800009
10.6 1470000800010
ENDDATA 3 0 1470000800011
ENDSUBENT 10 0 1470000899999
SUBENT 14700009 20210420 14831470000900001
BIB 2 2 1470000900002
REACTION (28-NI-0(N,EL)28-NI-0,,SIG) 1470000900003
STATUS (TABLE) Table II, page 135. 1470000900004
ENDBIB 2 0 1470000900005
NOCOMMON 0 0 1470000900006
DATA 1 1 1470000900007
DATA 1470000900008
B 1470000900009
18.0 1470000900010
ENDDATA 3 0 1470000900011
ENDSUBENT 10 0 1470000999999
SUBENT 14700010 20210420 14831470001000001
BIB 2 2 1470001000002
REACTION (29-CU-0(N,EL)29-CU-0,,SIG) 1470001000003
STATUS (TABLE) Table II, page 135. 1470001000004
ENDBIB 2 0 1470001000005
NOCOMMON 0 0 1470001000006
DATA 1 1 1470001000007
DATA 1470001000008
B 1470001000009
8.3 1470001000010
ENDDATA 3 0 1470001000011
ENDSUBENT 10 0 1470001099999
SUBENT 14700011 20210420 14831470001100001
BIB 2 2 1470001100002
REACTION (30-ZN-0(N,EL)30-ZN-0,,SIG) 1470001100003
STATUS (TABLE) Table II, page 135. 1470001100004
ENDBIB 2 0 1470001100005
NOCOMMON 0 0 1470001100006
DATA 1 1 1470001100007
DATA 1470001100008
B 1470001100009
3.7 1470001100010
ENDDATA 3 0 1470001100011
ENDSUBENT 10 0 1470001199999
SUBENT 14700012 20210420 14831470001200001
BIB 2 2 1470001200002
REACTION (47-AG-0(N,EL)47-AG-0,,SIG) 1470001200003
STATUS (TABLE) Table II, page 135. 1470001200004
ENDBIB 2 0 1470001200005
NOCOMMON 0 0 1470001200006
DATA 1 1 1470001200007
DATA 1470001200008
B 1470001200009
6.3 1470001200010
ENDDATA 3 0 1470001200011
ENDSUBENT 10 0 1470001299999
SUBENT 14700013 20210420 14831470001300001
BIB 2 2 1470001300002
REACTION (48-CD-0(N,EL)48-CD-0,,SIG) 1470001300003
STATUS (TABLE) Table II, page 135. 1470001300004
ENDBIB 2 0 1470001300005
NOCOMMON 0 0 1470001300006
DATA 1 1 1470001300007
DATA-APRX 1470001300008
B 1470001300009
1.2 1470001300010
ENDDATA 3 0 1470001300011
ENDSUBENT 10 0 1470001399999
SUBENT 14700014 20210420 14831470001400001
BIB 2 2 1470001400002
REACTION (50-SN-0(N,EL)50-SN-0,,SIG) 1470001400003
STATUS (TABLE) Table II, page 135. 1470001400004
ENDBIB 2 0 1470001400005
NOCOMMON 0 0 1470001400006
DATA 1 1 1470001400007
DATA 1470001400008
B 1470001400009
4.1 1470001400010
ENDDATA 3 0 1470001400011
ENDSUBENT 10 0 1470001499999
SUBENT 14700015 20210420 14831470001500001
BIB 2 2 1470001500002
REACTION (80-HG-0(N,EL)80-HG-0,,SIG) 1470001500003
STATUS (TABLE) Table II, page 135. 1470001500004
ENDBIB 2 0 1470001500005
NOCOMMON 0 0 1470001500006
DATA 1 1 1470001500007
DATA 1470001500008
B 1470001500009
4.7 1470001500010
ENDDATA 3 0 1470001500011
ENDSUBENT 10 0 1470001599999
SUBENT 14700016 20210420 14831470001600001
BIB 2 2 1470001600002
REACTION (82-PB-0(N,EL)82-PB-0,,SIG) 1470001600003
STATUS (TABLE) Table II, page 135. 1470001600004
ENDBIB 2 0 1470001600005
NOCOMMON 0 0 1470001600006
DATA 1 1 1470001600007
DATA 1470001600008
B 1470001600009
7.7 1470001600010
ENDDATA 3 0 1470001600011
ENDSUBENT 10 0 1470001699999
SUBENT 14700017 20210420 14831470001700001
BIB 2 2 1470001700002
REACTION (83-BI-209(N,EL)83-BI-209,,SIG) 1470001700003
STATUS (TABLE) Table II, page 135. 1470001700004
ENDBIB 2 0 1470001700005
NOCOMMON 0 0 1470001700006
DATA 1 1 1470001700007
DATA 1470001700008
B 1470001700009
10.2 1470001700010
ENDDATA 3 0 1470001700011
ENDSUBENT 10 0 1470001799999
ENDENTRY 17 0 1470099999999