ENTRY C2836 20221021 C283600000001 SUBENT C2836001 20221021 20231011 C283600100001 BIB 11 44 C283600100002 TITLE Cyclotron Targets: Preparation and Radiochemical C283600100003 Separation. III. Na22 C283600100004 AUTHOR (J.W.Irvine Jr,E.T.Clarke) C283600100005 REFERENCE (J,JCP,16,686,1948) C283600100006 #doi:10.1063/1.1746975 C283600100007 INSTITUTE (1USAMIT) C283600100008 FACILITY (CYCLO,1USAMIT) C283600100009 DETECTOR (PROPC) Gamma-ray activities from the Na24 generated C283600100010 in the individual foils were measured on a calibrated C283600100011 platinum screen wall counter shielded with 1/16" lead, C283600100012 and compared with a 10-microgram radium standard to C283600100013 obtain the absolute disintegration rates. Decays of C283600100014 several foils were also followed for a few days as a C283600100015 check on the identity of the activity. The Na22 C283600100016 positrons in the foils were measured with a bell-type C283600100017 thin window counter after the shorter-lived component C283600100018 had died away. C283600100019 SAMPLE The magnesium disks, because of their fragility, were C283600100020 sealed between layers of aluminum foil (0.00025") and C283600100021 stacked, resulting in a series of 24 absorbers whose C283600100022 average individual thickness was 7.7 mg/cm2 and whose C283600100023 total thickness, 185 mg/cm2, was approximately equal toC283600100024 the distance of penetration of the 14-MeV deuterons C283600100025 used. C283600100026 METHOD (CHSEP,STTA,ACTIV) The stack of foils was bombarded C283600100027 for 1.5 hours, 47.5-microampere minutes, with a C283600100028 deuteron beam whose initial energy was 14.20 MeV C283600100029 (range 184.5 mg/cm2 Al). After bombardment the C283600100030 targets should be allowed to age for about a week to C283600100031 allow the Na24 to decay, thus reducing the radiation C283600100032 hazard. The aged target is weighed and dissolved in C283600100033 50 percent excess of glacial acetic acid. With the C283600100034 metal the reaction is slow in starting but becomes C283600100035 very vigorous as it proceeds. After the reaction C283600100036 subsides, the solution is diluted with an equal C283600100037 volume of 50 percent alcohol. The last traces of C283600100038 metal are dissolved after 15-30 minutes. If any C283600100039 insoluble residue remains, it is removed by filtration.C283600100040 ERR-ANALYS (ERR-1) Even though individual thicknesses C283600100041 varied as much as 20 percent, the data could be C283600100042 corrected for these variations to reduce errors from C283600100043 this source to about 2 percent. C283600100044 CORRECTION Target thickness corrections. C283600100045 HISTORY (20221021C) BP C283600100046 ENDBIB 44 0 C283600100047 COMMON 1 3 C283600100048 ERR-1 C283600100049 PER-CENT C283600100050 2.0 C283600100051 ENDCOMMON 3 0 C283600100052 ENDSUBENT 51 0 C283600199999 SUBENT C2836002 20221021 20231011 C283600200001 BIB 3 3 C283600200002 REACTION (12-MG-24(D,A)11-NA-22,,SIG) C283600200003 DECAY-DATA (11-NA-22,3.0YR) C283600200004 STATUS (CURVE) Fig. 1, page 688 of J,JCP,16,686,1948. C283600200005 ENDBIB 3 0 C283600200006 NOCOMMON 0 0 C283600200007 DATA 2 23 C283600200008 EN DATA C283600200009 MEV B C283600200010 2.601 0.005 C283600200011 3.582 0.021 C283600200012 4.415 0.048 C283600200013 5.162 0.074 C283600200014 5.845 0.102 C283600200015 6.506 0.122 C283600200016 7.061 0.134 C283600200017 7.659 0.146 C283600200018 8.192 0.148 C283600200019 8.704 0.151 C283600200020 9.238 0.157 C283600200021 9.665 0.160 C283600200022 10.134 0.156 C283600200023 10.518 0.150 C283600200024 10.988 0.145 C283600200025 11.415 0.140 C283600200026 11.820 0.133 C283600200027 12.204 0.131 C283600200028 12.610 0.126 C283600200029 12.973 0.119 C283600200030 13.314 0.111 C283600200031 13.698 0.106 C283600200032 14.040 0.100 C283600200033 ENDDATA 25 0 C283600200034 ENDSUBENT 33 0 C283600299999 SUBENT C2836003 20221021 20231011 C283600300001 BIB 4 4 C283600300002 REACTION (12-MG-26(D,A)11-NA-24,,SIG) C283600300003 REL-REF (A,C2841002,M.C.Henderson,J,PR,48,855,1935) C283600300004 DECAY-DATA (11-NA-24,14.8HR) C283600300005 STATUS (CURVE) Fig. 1, page 688 of J,JCP,16,686,1948. C283600300006 ENDBIB 4 0 C283600300007 NOCOMMON 0 0 C283600300008 DATA 2 23 C283600300009 EN DATA C283600300010 MEV B C283600300011 2.579 0.005 C283600300012 3.582 0.021 C283600300013 4.415 0.039 C283600300014 5.119 0.054 C283600300015 5.887 0.070 C283600300016 6.527 0.079 C283600300017 7.104 0.082 C283600300018 7.701 0.090 C283600300019 8.213 0.096 C283600300020 8.726 0.093 C283600300021 9.216 0.093 C283600300022 9.686 0.092 C283600300023 10.155 0.087 C283600300024 10.518 0.084 C283600300025 11.009 0.079 C283600300026 11.436 0.077 C283600300027 11.863 0.070 C283600300028 12.226 0.068 C283600300029 12.610 0.064 C283600300030 12.994 0.064 C283600300031 13.335 0.060 C283600300032 13.698 0.054 C283600300033 14.040 0.052 C283600300034 ENDDATA 25 0 C283600300035 ENDSUBENT 34 0 C283600399999 ENDENTRY 3 0 C283699999999