ENTRY M0303 20160224 M082M030300000001 SUBENT M0303001 20160224 M082M030300100001 BIB 14 36 M030300100002 TITLE Photoneutrons from lead. M030300100003 AUTHOR (M.E.Toms,W.E.Stephens) M030300100004 INSTITUTE (1USANRL,1USAPEN) M030300100005 REFERENCE (J,PR,108,(1),77,1957) M030300100006 FACILITY (BETAT,1USAPEN) M030300100007 INC-SOURCE (BRST) M030300100008 SAMPLE A 1.247 g truncated lead sphere was 5 mm thick in the M030300100009 direction of the beam. M030300100010 METHOD (REC) M030300100011 PART-DET (P) M030300100012 DETECTOR (PLATE) 200 mu thick Ilford E-1 nuclear emulsions. M030300100013 CORRECTION The number of photoneutrons in each energy interval M030300100014 was obtained by taking into account: M030300100015 1) the probability of producing acceptable recoil M030300100016 protons in the volume of emulsion examined, which M030300100017 included (A) the number of hydrogen nuclei per unit M030300100018 of volume of nuclear emulsion, (B) the amount of M030300100019 neutron path length in the volume, (C) the M030300100020 neutron-proton scattering cross section, (D) the M030300100021 fraction of recoil lying within acceptable angles; M030300100022 2) the absorption of neutrons by the target and M030300100023 along their paths through the plates. M030300100024 ERR-ANALYS (ERR-S) Statistical errors are presented. M030300100025 ADD-RES (COMP) The energy distributions of neutrons are M030300100026 compared with the evaporation theory. M030300100027 (TRCS) A yield curve for the photoneutrons from lead M030300100028 was obtained using neutron counters in paraffin and M030300100029 was normalized at 23 MeV to the yield observed using M030300100030 nuclear emulsion. The cross section curve for lead M030300100031 was derived from the yield curve and X-ray energy M030300100032 spectrum by means of the photon difference method. M030300100033 HISTORY (19881227C) Data were compiled at SCJAD of Saratov M030300100034 State University. M030300100035 (19910202A) Corrected by V.Varlamov, V.Mclane M030300100036 (20160224A) Corrected by SD and VV: dates, STATUS, M030300100037 REACTION, lowercase. M030300100038 ENDBIB 36 0 M030300100039 COMMON 1 3 M030300100040 EN-MAX M030300100041 MEV M030300100042 23.0 M030300100043 ENDCOMMON 3 0 M030300100044 ENDSUBENT 43 0 M030300199999 SUBENT M0303002 20160224 M082M030300200001 BIB 5 22 M030300200002 REACTION (82-PB-0(G,X)0-NN-1,,DA/DE,,BRA/REL) M030300200003 ANALYSIS The energy distribution of the photoneutrons was M030300200004 obtained by (1) summing the neutrons in each energy M030300200005 interval over the angles 30, 50, 70, 90, 110, 130 M030300200006 and 150 degrees, (2) dividing the neutron sums by M030300200007 the sum of the fractional solid angles, (3) dividing M030300200008 by the number of moles of target irradiated by the M030300200009 beam and (4) dividing by the exposure in roentgens, M030300200010 corrected for the effective absorption of x-rays by M030300200011 the target. M030300200012 COMMENT Arbitrary unit = M030300200013 10**6* neutron/(0.5*MeV*mole*roentgen). M030300200014 The yield, in units 10**7 neutrons per M030300200015 mole-roentgen, was 1.4 with the error of 0.2. The M030300200016 calculated energy distribution which gave a M030300200017 satisfactory correspondence to the observed M030300200018 photoneutrons consisted of 90% evaporation from a M030300200019 compound nucleus and 10% emission by the resonance M030300200020 direct effect. M030300200021 STATUS (CURVE) Data from Fig.7 from PR,108,(1),77,1957. M030300200022 HISTORY (20160224A) Corrected by SD and VV: REACTION, BRS -> M030300200023 BRA, STATUS. M030300200024 ENDBIB 22 0 M030300200025 COMMON 3 3 M030300200026 E-ERR ANG-MIN ANG-MAX M030300200027 MEV ADEG ADEG M030300200028 0.25 30. 150. M030300200029 ENDCOMMON 3 0 M030300200030 DATA 3 17 M030300200031 E DATA ERR-S M030300200032 MEV ARB-UNITS ARB-UNITS M030300200033 0.75 1.90 0.41 M030300200034 1.25 5.19 0.45 M030300200035 1.75 5.15 0.44 M030300200036 2.25 4.70 0.43 M030300200037 2.75 3.20 0.37 M030300200038 3.25 1.48 0.27 M030300200039 3.75 1.26 0.26 M030300200040 4.25 1.52 0.29 M030300200041 4.75 1.03 0.26 M030300200042 5.25 1.08 0.25 M030300200043 5.75 0.89 0.25 M030300200044 6.25 0.49 0.17 M030300200045 6.75 0.32 0.15 M030300200046 7.25 0.16 0.12 M030300200047 7.75 0.08 0.07 M030300200048 8.25 0.00 M030300200049 8.75 0.08 0.08 M030300200050 ENDDATA 19 0 M030300200051 ENDSUBENT 50 0 M030300299999 SUBENT M0303003 20160224 M082M030300300001 BIB 5 9 M030300300002 REACTION (82-PB-0(G,X)0-NN-1,,DA/DE,,BRA/REL) M030300300003 ANALYSIS (INTED) M030300300004 COMMENT Arbitrary unit = M030300300005 10**4*neutron/(steradian*mole*roentgen). M030300300006 The angular distribution was fitted by the form M030300300007 A+B*sin**2 with B/A ratio of 0.23. M030300300008 STATUS (CURVE) Data from Fig.4 from PR,108,(1),77,1957. M030300300009 HISTORY (20160224A) Corrected by SD and VV: REACTION, BRS -> M030300300010 BRA, STATUS. M030300300011 ENDBIB 9 0 M030300300012 COMMON 1 3 M030300300013 E-MIN M030300300014 MEV M030300300015 4.0 M030300300016 ENDCOMMON 3 0 M030300300017 DATA 3 7 M030300300018 ANG DATA ERR-S M030300300019 ADEG ARB-UNITS ARB-UNITS M030300300020 30. 10.5 3.7 M030300300021 50. 7.9 3.0 M030300300022 70. 16.4 4.3 M030300300023 90. 20.4 5.2 M030300300024 110. 12.7 3.6 M030300300025 130. 14.0 3.6 M030300300026 150. 14.8 3.9 M030300300027 ENDDATA 9 0 M030300300028 ENDSUBENT 27 0 M030300399999 ENDENTRY 3 0 M030399999999