ENTRY L0279 20220316 L050L027900000001 SUBENT L0279001 20220316 L050L027900100001 BIB 10 28 L027900100002 TITLE High Energy Photo-Nuclear Reactions L027900100003 AUTHOR (K.Strauch) L027900100004 REFERENCE (J,PR,81,973,1951) L027900100005 #doi:10.1103/PhysRev.81.973 L027900100006 INSTITUTE (1USABRK) L027900100007 FACILITY (SYNCH,1USABRK) L027900100008 INC-SOURCE (BRST) 322-MeV bremsstrahlung from the Berkeley L027900100009 synchrotron. L027900100010 DETECTOR (GEMUC,THRES) Short bombardments of silver, copper, L027900100011 and polystyrene detectors result in activities L027900100012 produced primarily by (gamma,n) processes: L027900100013 Ag107(gamma,n) Ag106, 24 min (counting was started L027900100014 after the 2.3-min activity of Ag108 had died out); L027900100015 Cu63(gamma,n)Cu62 10.1 min; C12(gamma,n)C11, 20 min. L027900100016 METHOD (ACTIV) After bombardment the foils were rolled into L027900100017 cylinders having a diameter of 7/8 in., placed over L027900100018 Eck and Krebs thin-walled glass Geiger counters, and L027900100019 their activities compared. The consecutive L027900100020 interchange of samples compensated for the different L027900100021 counter efficiencies. L027900100022 ANALYSIS (DECAY) Decay curves were then taken for each sample L027900100023 and the different product activities separated. The L027900100024 irradiation time depends, of course, on the half-life L027900100025 and the yield of the product activity, but it was in L027900100026 general of the same order as the half-life. The L027900100027 values of effective photon energy (W), as obtained L027900100028 from the transition curves were used. L027900100029 HISTORY (20220316C) BP L027900100030 ENDBIB 28 0 L027900100031 NOCOMMON 0 0 L027900100032 ENDSUBENT 31 0 L027900199999 SUBENT L0279002 20220316 L050L027900200001 BIB 3 3 L027900200002 REACTION (6-C-12(G,N)6-C-11,,INT) L027900200003 DECAY-DATA (6-C-11,20.0MIN,B+,990.0) L027900200004 STATUS (TABLE) Table III, page 979. L027900200005 ENDBIB 3 0 L027900200006 NOCOMMON 0 0 L027900200007 DATA 2 1 L027900200008 EN-MAX DATA L027900200009 MEV B*MEV L027900200010 322. 0.090 L027900200011 ENDDATA 3 0 L027900200012 ENDSUBENT 11 0 L027900299999 SUBENT L0279003 20220316 L050L027900300001 BIB 3 6 L027900300002 REACTION (29-CU-63(G,N)29-CU-62,,INT) L027900300003 DECAY-DATA (29-CU-62,10.1MIN,B+,2920.0) L027900300004 (30-ZN-62,9.5HR,B+,660.0,0.1) L027900300005 (29-CU-64,12.8HR,B+,640.0,0.15, L027900300006 B-,570.0,0.31) L027900300007 STATUS (TABLE) Table III, page 979. L027900300008 ENDBIB 6 0 L027900300009 NOCOMMON 0 0 L027900300010 DATA 2 1 L027900300011 EN-MAX DATA L027900300012 MEV B*MEV L027900300013 322. 0.76 L027900300014 ENDDATA 3 0 L027900300015 ENDSUBENT 14 0 L027900399999 SUBENT L0279004 20220316 L050L027900400001 BIB 4 28 L027900400002 REACTION (30-ZN-0(G,TOT),,INT) L027900400003 ANALYSIS A lower limit to the total integrated cross section L027900400004 sigma int tot for photon absorption by the Zn nucleus L027900400005 can be estimated. Adding the integrated cross L027900400006 sections, for the (gamma,n), (gamma,2n),(gamma,p), L027900400007 (gamma,pn), and (gamma,p2n) reactions, a L027900400008 value of 1.2 MeV*barns is obtained. The relative L027900400009 yields, but not W are known for the (gamma,3n), L027900400010 (gamma,p3n), and (gamma,p4n) processes. By L027900400011 estimating the corresponding effective photon energies L027900400012 from the number of ejected nucleons, an additional L027900400013 contribution of about 0.2 MeV*barn is obtained. The L027900400014 fact that not all of the observed reactions started L027900400015 from the same Zn isotope should not greatly affect L027900400016 this result since the excited nuclei were all of the L027900400017 even-even type. L027900400018 DECAY-DATA (30-ZN-63,38.0MIN,B+,470.0,0.01, L027900400019 B+,1400.0,0.07, L027900400020 B+,2360.0,0.85) L027900400021 (29-CU-67,63.0HR,B-,560.0) L027900400022 (30-ZN-62,9.5HR,B+,660.0,0.1) L027900400023 (29-CU-62,10.1MIN,B+,2920.0) L027900400024 (29-CU-64,12.8HR,B+,640.0,0.15, L027900400025 B-,570.0,0.31) L027900400026 (29-CU-61,3.4HR,B+,1200.0,0.63, L027900400027 B+,550.0,0.025, L027900400028 B+,260.0,0.0003) L027900400029 STATUS (TABLE) page 980. L027900400030 ENDBIB 28 0 L027900400031 NOCOMMON 0 0 L027900400032 DATA 2 1 L027900400033 EN-MAX DATA-MIN L027900400034 MEV B*MEV L027900400035 322. 1.4 L027900400036 ENDDATA 3 0 L027900400037 ENDSUBENT 36 0 L027900499999 ENDENTRY 4 0 L027999999999