ENTRY 22185 19910722 00002218500000001 SUBENT 22185001 19910722 00002218500100001 BIB 14 64 2218500100002 REFERENCE (J,PR/C,41,862,9003) 2218500100003 TITLE -MECHANISM FOR ELECTRIC DIPOLE TRANSITIONS FROM THE 2218500100004 BROAD P-WAVE NEUTRON RESONANCE IN 24-MG. 2218500100005 AUTHOR (T.UCHIYAMA,M.IGASHIRA,H.KITAZAWA) 2218500100006 INSTITUTE (2JPNTIT) 2218500100007 FACILITY .3.2 MV PELLETRON ACCELERATOR AT TOKYO INST. OF TECH., 2218500100008 PULSED PROTON BEAM, REPETITION RATE 2 MHZ, PULSE WIDTH2218500100009 1.5 NS AND AVERAGE BEAM CURRENT 9 MICRO-AMP. 2218500100010 INC-SOURCE (P-LI7) LI EVAPORATED CU DISK. TARGET THICKNESS DETER- 2218500100011 MINED BY MEASURING NEUTRON TOF SPECTRA. 2218500100012 METHOD (TOF ) 2218500100013 (GSPEC) THE GAMMA PULSE-HEIGHT SPECTRA WERE UNFOLDED 2218500100014 BY AN ITERATIVE METHOD TO YIELD GAMMA ENERGY SPECTRA 2218500100015 AND YIELDS, USING THE MATRIX FORMED FROM THE PRODUCT 2218500100016 OF THE GAMMA RESPONSE MATRIX AND M-C GENERATED 2218500100017 CORRECTION MATRIX. 2218500100018 DETECTOR (NAICR) CAPTURE GAMMAS WERE DETECTED BY A NAI(TL) 2218500100019 DETECTOR 7.6 CM IN DIAM AND 15.2 CM LONG CENTERED IN 2218500100020 AN ANNULAR NAI(TL) DETECTOR 25.4 CM IN DIAM AND 2218500100021 28.0 CM LONG, PLACED IN A HEAVY SHIELD OF BORATED 2218500100022 PARAFFIN, LEAD AND CADMIUM, THE WHOLE DETECTOR BEING 2218500100023 OPERATED AS AN ANTI-COMPTON GAMMA SPECTROMETER. 2218500100024 A 6-LIH SHIELD WAS ADDED TO THE DETECTOR COLLIMATOR 2218500100025 TO ABSORB NEUTRONS SCATTERED BY THE SAMPLE. THE SAMPLE2218500100026 DETECTOR DISTANCE WAS 80 CM AND THE GAMMAS WERE 2218500100027 OBSERVED AT A LAB ANGLE OF 125 DEG TO THE PROTON BEAM.2218500100028 DETECTOR EFFICIENCY DETERMINED EXPERIMENTALLY USING 2218500100029 SEVERAL CALIBRATED SOURCES. 2218500100030 (SCIN ) 6-LI GLASS SCINTILLATION DETECTOR USED AS N 2218500100031 MONITOR LOCATED AT AN ANGLE OF 30 DEG TO THE P BEAM 2218500100032 (SCIN ) ANOTHER 6-LI GLASS SCINTILLATOR, 102 MM DIAM 2218500100033 BY 6.4 MM, PLACED AT AN ANGLE OF 7 DEG TO THE P BEAM 2218500100034 MEASURED INCIDENT NEUTRON TOF SPECTRA. ENERGY DEPEND- 2218500100035 ENCE OF DETECTOR EFFICIENCY CALCULATED BY A M-C METHOD2218500100036 SAMPLE .DISKS OF NATURAL MG, 60 MM DIAM BY 2 MM FOR THE 84 KEV2218500100037 RESONANCE EXPERIMENT AND 60 MM DIAM BY 12 MM FOR THE 2218500100038 266 KEV AND 431 KEV RESONANCE EXPERIMENTS. THE SAMPLE 2218500100039 THICKNESSES WERE CHOSEN TO GIVE THE N TRANSMISSIONS OF2218500100040 ABOUT 70 % AT THE RESONANCE PEAK, THUS REDUCING THE 2218500100041 MULTIPLE SCATTERING AND SELF-SHIELDING CORRECTIONS. 2218500100042 IN ATOMS/BARN THE SAMPLE THICKNESSES ARE: 2218500100043 84 KEV RES 6.78E-3 ATOM/B 2218500100044 266 AND 431 KEV RES 4.06E-2 ATOM/B 2218500100045 THE DISCS WERE PLACED 156 MM FROM THE NEUTRON SOURCE 2218500100046 AT 90 DEG TO THE PROTON BEAM DIRECTION. 2218500100047 .A GOLD STANDARD SAMPLE FOR NORMALISATION OF 24-MG 2218500100048 CAPTURE GAMMA YIELD, THICKNESS 1.02E-2 ATOM/B. 2218500100049 MONITOR (79-AU-197(N,G)79-AU-198,,SIG) DATA FROM ENDF/B-V 2218500100050 CORRECTION .SELF-SHIELDING AND MULTIPLE SCATTERING IN THE SAMPLE 2218500100051 .BACKROUND 2218500100052 .IN THE UNFOLDING OF THE PULSE-HEIGHT SPECTRA THE M-C 2218500100053 GENERATED CORRECTION MATRIX ACCOUNTED FOR PHOTO- 2218500100054 ELECTRIC ABSORPTION, COMPTON SCATTERING AND PAIR 2218500100055 CREATION OF GAMMAS IN THE SAMPLE. THE CORRECTION WAS 2218500100056 FOUND TO BE SEVERAL PERCENT AT MOST. 2218500100057 ERR-ANALYS (ERR-T) TOTAL ERROR OF PARTIAL RADIATIVE WIDTHS, 2218500100058 CALCULATED INCLUDING CONTRIBUTIONS FROM: 2218500100059 COUNTING STATISTICS 2 - 30 % 2218500100060 GAMMA DETECTOR EFFICIENCY 3 - 7 % 2218500100061 TOTAL CAPTURE YIELD OF 197-AU 5 % 2218500100062 CAPTURE CROSS SECTION OF 197-AU 5 % 2218500100063 STATUS .DATA TAKEN FROM MAIN REFERENCE. 2218500100064 HISTORY (910710C) S.W. 2218500100065 (910722E) 2218500100066 ENDBIB 64 0 2218500100067 NOCOMMON 0 0 2218500100068 ENDSUBENT 67 0 2218500199999 SUBENT 22185002 19910806 00002218500200001 BIB 6 26 2218500200002 REACTION (12-MG-24(N,G),PAR,WID,,,DERIV) 2218500200003 ANALYSIS (SLA ) RESONANCE ENERGY, TOTAL WIDTH AND NEUTRON WIDTH2218500200004 ALL TAKEN FROM MUGHABGHAB ET AL. 'NEUTRON CROSS 2218500200005 SECTIONS' (ACADEMIC, NEW YORK 1981) VOL. 1, P. 12-2. 2218500200006 .THE PARTIAL OFF-RESONANCE CROSS SECTIONS AT THE RES- 2218500200007 ONANCES CONSIDERED WERE CALCULATED ON THE BASIS OF 2218500200008 POTENTIAL-CAPTURE THEORY USING THE COMPUTER CODE 2218500200009 HIKARI. SUCH CALCULATIONS MAY INCLUDE ERRORS OF 20 - 2218500200010 30 %, BUT THESE CROSS SECTIONS ACCOUNT FOR ONLY 10 % 2218500200011 OF THE AVERAGE PARTIAL CROSS SECTIONS. 2218500200012 LEVEL-PROP (12-MG-25,E-LVL=0.0,SPIN=2.5,PARITY=+1.) 2218500200013 (12-MG-25,E-LVL=0.59,SPIN=0.5,PARITY=+1.) 2218500200014 (12-MG-25,E-LVL=0.98,SPIN=1.5,PARITY=+1.) 2218500200015 (12-MG-25,E-LVL=1.61,SPIN=3.5,PARITY=+1.) 2218500200016 (12-MG-25,E-LVL=1.97,SPIN=2.5,PARITY=+1.) 2218500200017 (12-MG-25,E-LVL=2.56,SPIN=0.5,PARITY=+1.) 2218500200018 (12-MG-25,E-LVL=2.74,SPIN=3.5,PARITY=+1.) 2218500200019 (12-MG-25,E-LVL=2.80,SPIN=1.5,PARITY=+1.) 2218500200020 (12-MG-25,E-LVL=3.41,SPIN=1.5,PARITY=-1.) 2218500200021 (12-MG-25,E-LVL=4.27,SPIN=0.5,PARITY=-1.) 2218500200022 (12-MG-25,E-LVL=5.47,SPIN=0.5,PARITY=+1.) 2218500200023 FLAG (2.) THESE THREE TRANSITIONS COULD NOT BE SEPARATED 2218500200024 THEREFORE ONLY THE SUM OF THE PARTIAL WIDTHS IS GIVEN 2218500200025 STATUS .DATA TAKEN FROM MAIN REFERENCE. 2218500200026 HISTORY (910710C) S.W. 2218500200027 (910722E) 2218500200028 ENDBIB 26 0 2218500200029 NOCOMMON 0 0 2218500200030 DATA 6 23 2218500200031 EN-RES E-LVL-FIN DATA DATA-MAX ERR-T FLAG 2218500200032 KEV MEV EV EV EV NO-DIM 2218500200033 84. 0.00 0.93 0.14 2218500200034 84. 0.59 3.98 0.57 2218500200035 84. 0.98 0.10 2218500200036 84. 1.97 0.20 0.03 2218500200037 84. 2.56 0.68 0.11 2218500200038 84. 4.27 0.03 2218500200039 266. 0.00 0.07 2218500200040 266. 0.59 6.07 2.2 2218500200041 266. 0.98 3.78 1.8 2218500200042 266. 1.61 0.13 0.40 2218500200043 266. 1.97 0.03 0.18 2218500200044 266. 2.56 2.73 0.86 2. 2218500200045 266. 2.74 2.73 0.86 2. 2218500200046 266. 2.80 2.73 0.86 2. 2218500200047 431. 0.00 0.35 0.07 2218500200048 431. 0.59 2.53 0.37 2218500200049 431. 0.98 0.48 0.07 2218500200050 431. 1.97 0.25 0.03 2218500200051 431. 2.56 1.04 0.14 2218500200052 431. 2.80 0.28 0.04 2218500200053 431. 3.41 0.18 2218500200054 431. 4.27 0.09 2218500200055 431. 5.47 0.10 2218500200056 ENDDATA 25 0 2218500200057 ENDSUBENT 56 0 2218500299999 SUBENT 22185003 19910722 00002218500300001 BIB 3 5 2218500300002 REACTION (12-MG-24(N,G),,WID) 2218500300003 STATUS .DATA TAKEN FROM MAIN REFERENCE. 2218500300004 (DEP,22185002) SUMS OF PARTIAL WIDTHS 2218500300005 HISTORY (910710C) S.W. 2218500300006 (910722E) 2218500300007 ENDBIB 5 0 2218500300008 NOCOMMON 0 0 2218500300009 DATA 3 3 2218500300010 EN-RES DATA ERR-T 2218500300011 KEV EV EV 2218500300012 84. 5.9 0.6 2218500300013 266. 12.5 4.2 2218500300014 431. 5.40 0.57 2218500300015 ENDDATA 5 0 2218500300016 ENDSUBENT 15 0 2218500399999 ENDENTRY 3 0 2218599999999