ENTRY M0450 20230614 M045000000001 SUBENT M0450001 20230614 20231011 M045000100001 BIB 13 71 M045000100002 TITLE Absolute cross section versus energy of the M045000100003 Cu-63(gamma,n) and Cu-63(gamma,2n) reactions. M045000100004 AUTHOR (A.I.Berman,K.L.Brown) M045000100005 REFERENCE (J,PR,96,83,1954) M045000100006 INSTITUTE (1USASTF) M045000100007 FACILITY (LINAC,1USASTF) M045000100008 INC-SOURCE (BRST) M045000100009 METHOD (STTA,ACTIV,BCINT) The stacked-foil method. The M045000100010 reaction yields were measured by determining the M045000100011 radioactivity of the ten-minute copper-62 and M045000100012 three-hour copper-61 nuclei which results from the M045000100013 (gamma,n) and (gamma,2n) processes, respectively, in M045000100014 copper-63. The number of photoneutrons ejected from M045000100015 the copper foil was determined by counting the M045000100016 residual radioactivity of the Cu-62 and Cu-61 M045000100017 isotopes with 4pi scintillation counter. M045000100018 SAMPLE The natural-copper foils used in the (gamma,n) runs M045000100019 were 1.25-inch diameter disks 40 mg/cm2 thick, while M045000100020 the enriched foils were 0.5 inch x 0.75-inch strips M045000100021 totaling 65 mg/cm2. Highly-enriched copper-63 foils: M045000100022 copper oxide containing 99.4% copper-63. Foils M045000100023 ranging in thickness from 3 to 16 mg/cm2 and M045000100024 totaling 130 mg/cm2 were made. M045000100025 DETECTOR (SCIN) 4Pi scintillation counter: the foil was M045000100026 sandwiched between two flat anthracene crystals, M045000100027 1.-inch square and 0.125-inch thick, backed by two M045000100028 DuMont 6292 photomultipliers. M045000100029 ANALYSIS (UNFLD,PHDIF) The number of photoneutrons ejected M045000100030 from the copper foil was determined by counting the M045000100031 residual radioactivity of the Cu-62 and Cu-61 M045000100032 isotopes with 4pi scintillation counter. Activation M045000100033 points were taken at 2 MeV intervals. The cross M045000100034 sections were computed from experimental yield M045000100035 curves by applying the photon-difference method M045000100036 using bremsstrahlung distributions calculated at 2 M045000100037 MeV intervals for a 0.025-radiation-length copper M045000100038 radiator. M045000100039 CORRECTION The cross sections given were corrected for M045000100040 contributions caused by the competing three-hour M045000100041 activity of Cu-61 (from Cu-63(g,2n) reaction) for M045000100042 twelve-hour Cu-64 activity (from Cu-65(g,n) M045000100043 reaction) which was evaluated by counting it after M045000100044 decay of the three-hour Cu-61 activity and then M045000100045 correcting by extrapolating back to the original M045000100046 Cu-64 activity and for multiple scattering of the M045000100047 primary electrons from Linac in the foils increases M045000100048 the effective path length of the bremsstrahlung M045000100049 quanta and electrons in the rear foil relative to M045000100050 the first (a correction for this was applied which M045000100051 varied from 4.0 to 0.4% from 12 to 36 MeV). M045000100052 COMMENT Experimental values were found for the absolute cross M045000100053 section of both Cu-63(gamma,n) and (gamma,2n) M045000100054 reactions versus gamma-quanta energy from threshold M045000100055 to 36 MeV. Statistical and systematic errors were M045000100056 limited by the use of: M045000100057 (a) the direct electron beam of the Stanford 36 MeV M045000100058 linear accelerator, which produced M045000100059 bremsstrahlung immediately before and within M045000100060 the copper foils under bombardment, M045000100061 (b) an electron-beam collector which recorded the M045000100062 total accumulated charge in the incident flux, M045000100063 (c) a 4pi scintillation counter which measured the M045000100064 activity of the resultant Cu-62 and Cu-61, M045000100065 (d) electroplated foils of separated Cu-63 M045000100066 isotopes. M045000100067 HISTORY (19910218C) M045000100068 (20180228A) Corrected by SD and VV: Updated to new M045000100069 date formats, lower case, STATUS, PART-DET deleted, M045000100070 REACTION, ERR-ANALYS moved to SUBENTs 002 - 006. M045000100071 (20230614A) Corrected by V.Varlamov: DATA in SUBENT M045000100072 005. M045000100073 ENDBIB 71 0 M045000100074 NOCOMMON 0 0 M045000100075 ENDSUBENT 74 0 M045000199999 SUBENT M0450002 20180228 M095M045000200001 BIB 5 10 M045000200002 REACTION (29-CU-63(G,N)29-CU-62,,SIG,,BRS) M045000200003 DECAY-DATA (29-CU-62,9.73MIN,B+) M045000200004 ERR-ANALYS (DATA-ERR) The error in the values of the integrated M045000200005 cross section. M045000200006 (ERR-1,1.,2.) An error of 1 to 2% arises from the M045000200007 calculation of the thick-target bremsstrahlung M045000200008 distribution M045000200009 STATUS (CURVE) Data from Fig. 5 from PR,96,83,1954. M045000200010 HISTORY (20180228A) Corrected by SD and VV: REACTION (BRS), M045000200011 DECAY-DATA, STATUS. M045000200012 ENDBIB 10 0 M045000200013 COMMON 2 3 M045000200014 ANAL-STEP DATA-ERR M045000200015 MEV PER-CENT M045000200016 2. 5. M045000200017 ENDCOMMON 3 0 M045000200018 DATA 2 9 M045000200019 EN DATA M045000200020 MEV MB M045000200021 13. 20.5 M045000200022 15. 48. M045000200023 17. 96. M045000200024 19. 73. M045000200025 21. 14.5 M045000200026 23. 12. M045000200027 25. 5. M045000200028 27. 2.5 M045000200029 29. .5 M045000200030 ENDDATA 11 0 M045000200031 ENDSUBENT 30 0 M045000299999 SUBENT M0450003 20180228 M095M045000300001 BIB 5 7 M045000300002 REACTION (29-CU-63(G,2N)29-CU-61,,SIG,,BRS) M045000300003 DECAY-DATA (29-CU-61,3.32HR,B+) M045000300004 ERR-ANALYS (DATA-ERR) The error in the values of the integrated M045000300005 cross section. M045000300006 STATUS (CURVE) Data from Fig. 6 from PR,96,83,1954. M045000300007 HISTORY (20180228A) Corrected by SD and VV: REACTION (BRS), M045000300008 DECAY-DATA, STATUS. M045000300009 ENDBIB 7 0 M045000300010 COMMON 1 3 M045000300011 DATA-ERR M045000300012 PER-CENT M045000300013 20. M045000300014 ENDCOMMON 3 0 M045000300015 DATA 2 8 M045000300016 EN DATA M045000300017 MEV MB M045000300018 21. 4.05 M045000300019 23. 6.55 M045000300020 25. 12.2 M045000300021 27. 10.05 M045000300022 29. 3.6 M045000300023 31. 3.2 M045000300024 33. 2.1 M045000300025 35. 1.05 M045000300026 ENDDATA 10 0 M045000300027 ENDSUBENT 26 0 M045000399999 SUBENT M0450004 20180228 M095M045000400001 BIB 3 8 M045000400002 REACTION ((29-CU-63(G,2N)29-CU-61,,SIG,,BRS)/ M045000400003 ((29-CU-63(G,N)29-CU-62,,SIG,,BRS)+ M045000400004 (29-CU-63(G,2N)29-CU-61,,SIG,,BRS))) M045000400005 STATUS (DEP,M0450002) M045000400006 (DEP,M0450003) M045000400007 (TABLE) Data from Table II of PR,96,83,1954. M045000400008 HISTORY (20180228U) Corrected by SD and VV: REACTION (BRS), M045000400009 STATUS. M045000400010 ENDBIB 8 0 M045000400011 NOCOMMON 0 0 M045000400012 DATA 2 4 M045000400013 EN DATA M045000400014 MEV NO-DIM M045000400015 21. 0.13 M045000400016 23. 0.43 M045000400017 25. 0.71 M045000400018 27. 0.79 M045000400019 ENDDATA 6 0 M045000400020 ENDSUBENT 19 0 M045000499999 SUBENT M0450005 20230614 20231011 M045000500001 BIB 4 14 M045000500002 REACTION (29-CU-63(G,N)29-CU-62,,INT,,BRS) M045000500003 ERR-ANALYS (DATA-ERR) The error in the values of the integrated M045000500004 cross section. M045000500005 No information on the source of the uncertainty. M045000500006 (ERR-1,1.,2.) An error of 1 to 2% arises from the M045000500007 calculation of the thick-target bremsstrahlung M045000500008 distribution. The limit of accuracy of the electron M045000500009 collector is 2%, and fluctuactions in foil mass per M045000500010 unit area constitute the remainder of the major M045000500011 errors. M045000500012 STATUS (TABLE) Data from Table III of PR,96,83,1954. M045000500013 HISTORY (20180228U) Corrected by SD and VV: STATUS. M045000500014 (20230614A) Corrected by V.Varlamov: ERR-ANALYS, M045000500015 REACTION, DATA, DATA-ERR deleted. M045000500016 ENDBIB 14 0 M045000500017 COMMON 1 3 M045000500018 DATA-ERR M045000500019 PER-CENT M045000500020 5. M045000500021 ENDCOMMON 3 0 M045000500022 DATA 3 1 M045000500023 EN-MIN EN-MAX DATA M045000500024 MEV MEV MB*MEV M045000500025 11. 35. .55 M045000500026 ENDDATA 3 0 M045000500027 ENDSUBENT 26 0 M045000599999 SUBENT M0450006 20180228 M095M045000600001 BIB 4 5 M045000600002 REACTION (29-CU-63(G,2N)29-CU-61,,INT) M045000600003 ERR-ANALYS (DATA-ERR) The error in the values of the integrated M045000600004 cross section. M045000600005 STATUS (TABLE) Data from the text on p.89 of PR,96,83,1954. M045000600006 HISTORY (20180228U) SD+VV: STATUS added. M045000600007 ENDBIB 5 0 M045000600008 COMMON 1 3 M045000600009 DATA-ERR M045000600010 PER-CENT M045000600011 20. M045000600012 ENDCOMMON 3 0 M045000600013 DATA 3 1 M045000600014 EN-MIN EN-MAX DATA M045000600015 MEV MEV MB*MEV M045000600016 20. 36. .081 M045000600017 ENDDATA 3 0 M045000600018 ENDSUBENT 17 0 M045000699999 ENDENTRY 6 0 M045099999999