ENTRY 14744 20220208 14971474400000001 SUBENT 14744001 20220208 14971474400100001 BIB 10 33 1474400100002 TITLE (n,2n) cross section of Be9 1474400100003 AUTHOR (H.M.Agnew) 1474400100004 REFERENCE (R,LA-1371,1952) 1474400100005 INSTITUTE (1USALAS) 1474400100006 DETECTOR (LONGC) A long counter which had a flat response. 1474400100007 METHOD (SHELT) By measuring the transmission of shells of 1474400100008 graphite of various thicknesses. A series of shells 1474400100009 having a diameter up to 9 in. all gave a transmission 1474400100010 of unity. 1474400100011 ANALYSIS The cross section was computed as I = I0*exp((sigma 1474400100012 n,2n - sigma a)Nt), where I is the number of 1474400100013 neutrons per standard time interval detected by the 1474400100014 long counter with the sphere of Be surrounding the 1474400100015 neutron source. I0 is the number of neutrons detected 1474400100016 under identical conditions except with source bare, 1474400100017 sigma n,2n is the average cross section of Be per 1474400100018 atom for the (n,2n) reaction for the neutron spectrum 1474400100019 involved, sigma a is the average absorption cross 1474400100020 section of Be per atom for the neutron spectrum 1474400100021 involved, and t is the wall thickness in source. 1474400100022 ERR-ANALYS (DATA-ERR) The relatively large errors (average 1474400100023 deviation from the mean) are due primarily to the 1474400100024 misfit cavities in the Be spheres, cracks in in size of1474400100025 the Be spheres. 1474400100026 (ERR-S,,1.) In the experiment reported the here 1474400100027 the source was 80 cm from statistical errors involved 1474400100028 were less than 1%. 1474400100029 COMMENT Compiler's comment: The difference between (n,2n) and 1474400100030 the absorption cs would have to be negative, because 1474400100031 "absorption" as defined in EXFOR includes (n,2n). In 1474400100032 old papers "absorption" is often used for "capture", so1474400100033 (N,ABS) was replaced with (N,G). 1474400100034 HISTORY (20220208C) BP 1474400100035 ENDBIB 33 0 1474400100036 NOCOMMON 0 0 1474400100037 ENDSUBENT 36 0 1474400199999 SUBENT 14744002 20220208 14971474400200001 BIB 3 4 1474400200002 REACTION ((4-BE-9(N,2N)4-BE-8,,SIG,,SPA)- 1474400200003 (4-BE-9(N,G)4-BE-10,,SIG,,SPA)) 1474400200004 INC-SOURCE (RA-BE) 1474400200005 STATUS (TABLE) page 5. 1474400200006 ENDBIB 4 0 1474400200007 COMMON 1 3 1474400200008 EN-MAX 1474400200009 MEV 1474400200010 12.0 1474400200011 ENDCOMMON 3 0 1474400200012 DATA 2 1 1474400200013 DATA DATA-ERR 1474400200014 B B 1474400200015 0.20 0.04 1474400200016 ENDDATA 3 0 1474400200017 ENDSUBENT 16 0 1474400299999 SUBENT 14744003 20220208 14971474400300001 BIB 3 4 1474400300002 REACTION ((4-BE-9(N,2N)4-BE-8,,SIG,,SPA)- 1474400300003 (4-BE-9(N,G)4-BE-10,,SIG,,SPA)) 1474400300004 INC-SOURCE (PO-BE) 1474400300005 STATUS (TABLE) page 5. 1474400300006 ENDBIB 4 0 1474400300007 COMMON 1 3 1474400300008 EN-MAX 1474400300009 MEV 1474400300010 12.0 1474400300011 ENDCOMMON 3 0 1474400300012 DATA 2 1 1474400300013 DATA DATA-ERR 1474400300014 B B 1474400300015 0.24 0.07 1474400300016 ENDDATA 3 0 1474400300017 ENDSUBENT 16 0 1474400399999 SUBENT 14744004 20220208 14971474400400001 BIB 3 4 1474400400002 REACTION ((4-BE-9(N,2N)4-BE-8,,SIG,,SPA)- 1474400400003 (4-BE-9(N,G)4-BE-10,,SIG,,SPA)) 1474400400004 INC-SOURCE A mock fission spectrum. 1474400400005 STATUS (TABLE) page 5. 1474400400006 ENDBIB 4 0 1474400400007 COMMON 1 3 1474400400008 EN-APRX 1474400400009 MEV 1474400400010 2.0 1474400400011 ENDCOMMON 3 0 1474400400012 DATA 2 1 1474400400013 DATA DATA-ERR 1474400400014 B B 1474400400015 -0.16 0.13 1474400400016 ENDDATA 3 0 1474400400017 ENDSUBENT 16 0 1474400499999 ENDENTRY 4 0 1474499999999