ENTRY C2506 20210518 C204C250600000001 SUBENT C2506001 20210518 C204C250600100001 BIB 11 51 C250600100002 TITLE Be(p,2n)B8 reaction as a neutrino source C250600100003 AUTHOR (N.E.Davison,M.J.Canty,D.A.Dohan,A.Mcdonald) C250600100004 INSTITUTE (1CANMNA) C250600100005 REFERENCE (J,PR/C,10,50,1974) C250600100006 #doi:10.1103/PhysRevC.10.50 C250600100007 FACILITY (CYCLO,1CANMNA) C250600100008 SAMPLE A self-supporting beryllium metal foil of C250600100009 9.1 mg/cm2 thickness. C250600100010 DETECTOR (NAICR) Two 5.1 x 3.2 cm NaI crystals operated in C250600100011 fast-slow coincidence. C250600100012 METHOD (COINC,GSPEC,EXTB) The proton current 60 nA was C250600100013 collected in a Faraday cup. The beam was pulsed: C250600100014 0.7 sec irradiation interval, a 10.0 sec counting C250600100015 interval. The target was mounted at the center of an C250600100016 annular aluminum stopper 10 cm long, and with a wall C250600100017 thickness of 3.8 cm. Pairs of 511 keV quanta were C250600100018 detected in two NaI crystals operated in fast-slow C250600100019 coincidence. The coincidence resolving time of the C250600100020 detectors was 12 nsec full width at half maximum. C250600100021 The absolute efficiency of the apparatus as a detector C250600100022 of B-8 positrons was obtained in two stages: (i) The C250600100023 distribution of the stopped positrons in the aluminum C250600100024 stopper was calculated; and (ii) a Na-22 source of C250600100025 known strength was used to measure experimentally the C250600100026 efficiency. C250600100027 CORRECTION Correction was made: C250600100028 - to take into account those B-8 nuclei which recoil C250600100029 out of the target at angles such as to be lost; this C250600100030 correction is approximately 4% at Ep = 30 MeV and C250600100031 12% at Ep =47.5 MeV, C250600100032 - for positron annihilation in flight. ' C250600100033 ERR-ANALYS (ERR-T) The errors on the cross sections were C250600100034 obtained by adding in quadrature statistical errors in C250600100035 the number of counts attributed to B-8, statistical C250600100036 errors in the background subtraction, inaccuracy in C250600100037 the estimation of time at which the beam was cut off. C250600100038 (ERR-1) uncertainty in the strength of the Na-22 sourceC250600100039 used to obtain the stopper efficiency (5%), C250600100040 (ERR-2) statistical uncertainty in the efficiency C250600100041 calibration (2%), C250600100042 (ERR-3) inaccuracies in the range formulas and the C250600100043 computation of the distribution of positrons stopped inC250600100044 the aluminum stopper (5%), C250600100045 (ERR-4) inaccuracy in the estimation of time at which C250600100046 the beam was cut off (3%), C250600100047 (ERR-5) uncertainty in target thickness (5%), C250600100048 (ERR-6) uncertainty in the correction for annihilation C250600100049 in flight (2%), C250600100050 (ERR-7,2.,6.) uncertainty in the correction for lost C250600100051 recoil 8B nuclei (2% at Ep=30 MeV, 6% at Ep=47.5 MeV). C250600100052 HISTORY (20210518C) OG C250600100053 ENDBIB 51 0 C250600100054 COMMON 6 3 C250600100055 ERR-1 ERR-2 ERR-3 ERR-4 ERR-5 ERR-6 C250600100056 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT C250600100057 5. 2. 5. 3. 5. 2. C250600100058 ENDCOMMON 3 0 C250600100059 ENDSUBENT 58 0 C250600199999 SUBENT C2506002 20210518 C204C250600200001 BIB 3 4 C250600200002 REACTION (4-BE-9(P,2N)5-B-8,,SIG) C250600200003 DECAY-DATA (5-B-8,0.762SEC,B+) C250600200004 STATUS (CURVE) Fig.3 in Phys.Rev.C,10,50,1974 was digitized C250600200005 by GSYS2.4.7. C250600200006 ENDBIB 4 0 C250600200007 NOCOMMON 0 0 C250600200008 DATA 3 9 C250600200009 EN DATA ERR-T C250600200010 MEV MB MB C250600200011 22.021 0.016 0.012 C250600200012 25.088 0.058 0.007 C250600200013 30.104 0.163 0.013 C250600200014 30.113 0.195 0.012 C250600200015 35.182 0.282 0.017 C250600200016 40.125 0.237 0.017 C250600200017 45.093 0.274 0.018 C250600200018 47.586 0.223 0.017 C250600200019 47.604 0.286 0.017 C250600200020 ENDDATA 11 0 C250600200021 ENDSUBENT 20 0 C250600299999 ENDENTRY 2 0 C250699999999