/* 2002-03-18 N.OTUKA 10 POINTS CHECK */ /* 2006-02-23 N.OTUKA - Backing thickness added in EXP,1[3 - INC-ENGY-RANGE=MEV deleted in DATA,1 */ /* 2006-02-26 N.OTUKA - ENGY-GAMM -> ENGY-GAMMA in DATA,1 */ \\BIB,1[3; D#=D204; TITLE=/GAMMA DECAY OF G9/2 ISOBARIC ANALOG RESONANCE IN 57CO/; PURPOSE=/FOR THE COPPER ISOTOPES(A=59[63) THE STRENGTH OF G9/2 IAR TO ANTI-IAR(AIAR) TRANSITION IS IN THE RANGE OF 10[20 % OF THE S.P. ESTIMATES, GRADUALLY INCREASING WITH MASS NUMBER. ON EITHER SIDE OF THESE NUCLEI,HOWEVER, THE STRENGTH OF THIS TRANSITION SEEMS TO BE REDUCED. TO BETTER UNDERSTAND THIS PHENOMENON AND TO COMPLETE THE M1 STRENGTH SYSTEMATICS, FURTHER DATA ON TARGET NUCLEI WHOSE 1F9/2 PROTON SHELL IS NOT COMPLETELY FILLED WOULD BE VERY USEFUL. WE STUDIED THE 56FE(P,GAMMA)57CO REACTION TO LOCATE THE 9/2+ IAR AND AIAR AND INVESTIGATED THE DECAY OF THE IAR./; ATH=(C.RANGACHARYULU'1',I.M.SZOGHY'1',C.ST-PIERRE'1',K.RAMAVATARAM'1'); INST-ATH=(1CANLUQ'1'); REF=PR/C; VLP=19(1979)1762; RCTS=(56FE(P,GAMMA)57CO); \\EXP,1[3; RCT=56FE(P,GAMMA)57CO; ENR=99%; THK-TGT=20UG/CM**2; BAC=C; THK-BAC=20UG/CM**2; POL-TGT=NO; ALGN-TGT=NO; ACC=(VDG); INST-ACC=1CANLUQ; INC-ENGY-RANGE=(3.7MEV[3.8MEV); DELTA-INC-ENGY=XKEV; ERS-PRJ=XKEV; POL-PRJ=NO; DET-PARTCL=(GAMMA); /*@3@*/ DET-SYS=(GE(LI)); SOLID-ANGL=XMSR; ERS-DET=1KEV; ANL=(SHELL-MODEL); PHQ=(EXC-FUNCT,ANGL-DSTRN'8',EXC-ENGY,RESN-ENGY,SPIN'8',PTY'8',IAS'6',B E-L,BM-L); /*@6@*/ /*@8@*/ \\DATA,1; CMPD=57CO; RSD=57CO; EXC-ENGY=XMEV; DELTA-EXC-ENGY=XKEV; ENGY-GAMMA=845KEV; /*@5@*/ /*FIG.1-(A)*/ /* D204 FIG 1-(A) */ /* SER#= 1 */ /* XSCALE=LINEAR YSCALE=LINEAR */ /* XMAX= 3.740E+02*1E-2 YMAX= 3.000E+04 */ /* XMIN= 3.710E+02*1E-2 YMIN= 0.000E+00 */ /* FOLLOWING DATA ARE TAKEN FROM GRAPH */ \DATA; INC-ENGY-LAB COUNTS (MEV) (UNIT'4') 3.7116 6.92E+03 3.7130 9.36E+03 3.7145 1.20E+04 3.7158 7.73E+03 3.7174 7.22E+03 3.7187 7.12E+03 3.7202 6.92E+03 3.7220 3.25E+03 3.7231 3.86E+03 3.7237 1.88E+04 3.7246 3.15E+04 3.7256 2.28E+04 3.7259 8.44E+03 3.7268 6.00E+03 3.7275 3.36E+03 3.7281 3.46E+03 3.7287 4.17E+03 3.7293 4.47E+03 3.7303 5.39E+03 3.7316 9.15E+03 3.7325 5.49E+03 3.7330 3.05E+03 3.7344 1.83E+03 3.7362 6.00E+03 3.7375 2.75E+03 3.7388 2.24E+03 \END; \\DATA,2; CMPD=57CO; RSD=57CO; EXC-ENGY=X'6'MEV; DELTA-EXC-ENGY=XKEV; J-PI=X'6'; ENGY-GAMMA=8.6[9.7MEV; /*@7@*/ /*@6@*/ /*FIG.1-(B)*/ /* D204 FIG 1-(B) */ /* SER#= 2 */ /* XSCALE=LINEAR YSCALE=LINEAR */ /* XMAX= 3.740E+02*1E-2 YMAX= 1.000E+02 */ /* XMIN= 3.710E+02*1E-2 YMIN= 0.000E+00 */ /* FOLLOWING DATA ARE TAKEN FROM GRAPH */ \DATA; INC-ENGY-LAB COUNTS (MEV) (UNIT'4') 3.7114 8.12E+00 3.7130 5.08E+00 3.7145 1.12E+01 3.7156 4.57E+00 3.7173 1.27E+01 3.7187 5.08E+00 3.7202 7.61E+00 3.7213 8.22E+01 3.7217 1.06E+02 3.7228 8.68E+01 3.7231 3.05E+01 3.7244 1.62E+01 3.7258 4.57E+00 3.7272 1.27E+01 3.7282 8.22E+01 3.7286 1.13E+02 3.7296 8.43E+01 3.7303 2.74E+01 3.7318 1.47E+01 3.7330 4.06E+00 3.7344 1.32E+01 3.7360 7.61E+00 3.7374 4.57E+00 3.7388 5.58E+00 \END; \\DATA,3; /*@9@*/ /*@17@*/ CMPD=57CO; RSD=57CO; \DATA; DATA1'10' J-PI DATA2'11' J-PI DATA3'12' DATA3-ERR BE-1'16' BM-1'16' RATIO'15,16' (MEV) (NODIM) (MEV) (NODIM) (EV) (EV) (UNIT1'13) (UNIT2'14') (NODIM) 9.690 9/2+ 0.0 7/2- 0.137 0.020 1.44 X X 9.690 9/2+ 1.223 9/2- 0.029 0.005 4.56E-4 X X 9.690 9/2+ 4.597 9/2+ 0.029 0.006 X 1.89E-2 0.011 \END; /*@10@*/ /*@11@*/ /*@12@*/ /*@13@*/ /*@14@*/ /*@15@*/ /*@16@*/ \\END; @@3; METHOD = DETAILS OF THE TARGET CHAMBER, THE DETECTION SYSTEM, AND THE EXPERIMENTAL PROCEDURE HAVE BEEN DESCRIBED EARLIER; K.RAMAVATARAM ET AL.,PHYS.REV.C9(1974)237, IBID. C17(1978)1583. @@4; '4' UNIT = COUNTS/100 MICRO-CURIE @@5; DATA = EXCITATION FUNCTION FOR (P,P' GAMMA) WITH E(GAMMA)=845 KEV. @@6; '6' A WINDOW WAS SET TO COUNT GAMMA RAYS BETWEEN 8.6 AND 9.7 MEV. IN THIS REGION TWO RESONANCES WERE OBERVED AT E(PROTON)=3.72/ AND 3.728 MEV, WITH AN INTENSE GAMMA-RAY TRANSITION TO THE GROUND STATE. THE RESONANT LEVEL(R) FOR E(PROTON)=3.728 MEV WAS FOUND TO DECAY ONLY TO KNOWN HIGH SPIN STATES GS(7/2-), 1.223(9/2-) AND TO THE STATE AT 4.597 MEV. THE ON RESONANCE GAMMA-RAY SPECTRUM IS SHOWH IN FIG.2. THIS RESONANCE IS MOST LIKELY THE 9/2+ IAR. @@7; DATA = EXCITATION FUNCTION FOR RESONANCES TO GROUND STATE TRANSITION IN (P,GAMMA) REACTION. @@8; '8' THE ANGULAR DISTRIBUTIONS OF PRIMARY GAMMA RAYS, BETWEEN 0 AND 90 DEGREES, WERE OBTAINED FOR THE 3.728MEV RESONACE(R) TO G.S.(7/2-), R TO 1.223MEV(9/2-), AND R TO 4.597MEV(7/2+,9/2+) TRANSITIONS AS WELL AS THOSE OF THE SECONDARY GAMMA RAYS FOR THE 4.597 TO 2.311MEV(7/2-) AND THE 4.597 TO G.S.(7/2-) TRANSITIONS. @@9; TABLE = GAMMA-DECAY PROPERTIES OF THE 9/2+ IAR IN THE 56FE(P,GAMMA) 57CO REACTION @@10; DATA1 = INITIAL STATE OF TRANSITION @@11; DATA2 = FINAL STATE OF TRANSITION @@12; DATA3 = WIDTH(P)*WIDTH(GAMMA)/(TOTAL WIDTH) @@13; UNIT1 = (E*FM**2)**2 @@14; UNIT2 = (NUCLEAR MAGNETON)**2 @@15; '15' RATIO = PARTIAL LEVEL WIDTH OF GAMMA RATIO OF WIDTH(EXP)/WIDTH(S.P.) @@16; '16' DEDUCED WITH THE CONVENTIONAL ASSUMPTION WIDTH(TOT) = WIDTH(P) >> WIDTH(GAMMA). @@17; ANALYSIS = TO EXTRACT THE G.S. TRANSITION STRENGTH, THE YIELD FOR THE FULL ENERGY AND TWO ESCAPE PEAKS, WITH PROPER BACKGROUND SUBTRAC- TION, WAS USED. THIS YIELD IS CLOSELY 0.37 TIMES THE ONE SEEN IN \\DATA1,2. @@;