ENTRY 23291 20160325 22492329100000001 SUBENT 23291001 20160325 22492329100100001 BIB 13 39 2329100100002 TITLE The disintegration of 7Be by slow neutrons. 2329100100003 AUTHOR (R.C.Hanna) 2329100100004 INSTITUTE (2UK HAR) 2329100100005 REFERENCE (J,PM,46,381,1955) 2329100100006 REL-REF (O,,R.C.Hanna,J,PM,46,381,1955) 2329100100007 CS for Li-7(p,n) at 13 and 18 keV - 2329100100008 (5.2+-0.6)*10-2 b and (4.8+-0.5)*10-2 b. 2329100100009 FACILITY (REAC,2UK HAR) Harwell pile B.E.P.O. 2329100100010 INC-SOURCE (REAC) Collimated beam of thermal neutrons. 2329100100011 SAMPLE Be-7 was prepared by bombardment of a block of pile 2329100100012 graphite with the 175 MeV internal proton beam of the 2329100100013 Harwell cyclotron.After chemical separation the Be-7 2329100100014 was deposited on Pt sheet as a "weightless" source. 2329100100015 The mass of Be-7 was determined from the counting rate 2329100100016 due to 478 keV gamma-rays detected in an organic 2329100100017 scintillation crystal relative to the rate due to 2329100100018 411 keV gamma-rays from Au-198 source. 2329100100019 Be-7 absolute activity (5.4+-0.1)*10**6 gammas/sec, 2329100100020 corresponding mass (3.76+-0.40)*10**-9 g of Be-7. 2329100100021 Sample was mounted on the source electrode of IOCH . 2329100100022 PHDs were measured at different filling gas pressure. 2329100100023 DETECTOR (IOCH) Parallel plate gridded ionization chamber . 2329100100024 METHOD (PHD) Pulse-height spectra measured. 2329100100025 Cd difference curves . 2329100100026 Intensity of proton group was measured to be of the 2329100100027 expected 53d half-life. 2329100100028 DECAY-DATA (4-BE-7,53.D) 2329100100029 ADD-RES The cross section for all processes leading to the 2329100100030 destruction of Be-7 was measured to be 2329100100031 SIG=(4.8+-0.9)*10**b by using the ratio of activities 2329100100032 of two Be-7 samples, one of which was irradiated for 2329100100033 28 days ( integrated flux F=(1.36+-0.10)*10**18). 2329100100034 Spectra were studded by NaI scintillator and organic 2329100100035 crystal detector. 2329100100036 Ratio of activities of two samples: 2329100100037 before irradiation Y=1.112+-0.009 ; 2329100100038 after irradiation of stronger sample - Y1=1.043+-0.005.2329100100039 Used formula: Y1=Y*exp(-SIG*F) . 2329100100040 HISTORY (20160325C) M.M. 2329100100041 ENDBIB 39 0 2329100100042 NOCOMMON 0 0 2329100100043 ENDSUBENT 42 0 2329100199999 SUBENT 23291002 20160325 22492329100200001 BIB 3 5 2329100200002 REACTION (4-BE-7(N,P)3-LI-7,,SIG) 2329100200003 ERR-ANALYS (ERR-T) Total error 2329100200004 (ERR-1) Uncertainty of mass determination due to 2329100200005 uncertainty on branching ratio. 2329100200006 STATUS (TABLE) Text, page 381, of J,PM,46,381,1955 2329100200007 ENDBIB 5 0 2329100200008 COMMON 1 3 2329100200009 ERR-1 2329100200010 PER-CENT 2329100200011 10. 2329100200012 ENDCOMMON 3 0 2329100200013 DATA 3 1 2329100200014 EN-DUMMY DATA ERR-T 2329100200015 EV B B 2329100200016 0.0253 5.3E+4 0.8E+4 2329100200017 ENDDATA 3 0 2329100200018 ENDSUBENT 17 0 2329100299999 SUBENT 23291003 20160325 22492329100300001 BIB 2 2 2329100300002 REACTION (4-BE-7(N,X)2-HE-4,,SIG) 2329100300003 STATUS (TABLE) Text, page 381, of J,PM,46,381,1955 2329100300004 ENDBIB 2 0 2329100300005 NOCOMMON 0 0 2329100300006 DATA 2 1 2329100300007 EN-DUMMY DATA-MAX 2329100300008 EV B 2329100300009 0.0253 1. 2329100300010 ENDDATA 3 0 2329100300011 ENDSUBENT 10 0 2329100399999 ENDENTRY 3 0 2329199999999