ENTRY            30781   20220202                             32073078100000001 
SUBENT        30781001   20220202                             32073078100100001 
BIB                 19         92                                 3078100100002 
TITLE      Neutron capture cross section measurement of 232Th in  3078100100003 
           the energy range of 400-950 keV                        3078100100004 
AUTHOR     (R.P.Anand, H.M.Jain, S.Kailas, S.K.Gupta,             3078100100005 
            V.S.Ramamurthy)                                       3078100100006 
INSTITUTE  (3INDTRM)                                              3078100100007 
REFERENCE  (J,ANE,16,87,1989)                                     3078100100008 
           ((J,RE,93,189,1986)=(C,85SANTA,1,525,1985))            3078100100009 
            Prelim. of the ANE article                            3078100100010 
FACILITY   (VDG,3INDTRM) 5.5 MeV accelerator                      3078100100011 
SAMPLE     - The Th-oxide target in form of discs (~14 mm diam.,  3078100100012 
            2 mm thick).                                          3078100100013 
           - Two thin Au foils (0.013 mm thick, ~14 mm diam.)     3078100100014 
INC-SOURCE (P-LI7)                                                3078100100015 
DETECTOR   (GELI) 100 cm3                                         3078100100016 
METHOD     (ACTIV)                                                3078100100017 
           - Activation method was employed in which the gammas   3078100100018 
             emitted from the decay of the Th-233 were measured.  3078100100019 
           - The cross sections were measured relative to the     3078100100020 
             neutron capture cross sections of Au-197.            3078100100021 
ANALYSIS   The photopeak area of 459 keV g-ray was extracted with 3078100100022 
            the computer code SAMPO, which fits each gamma-ray    3078100100023 
            with Gaussian + two exponentials.                     3078100100024 
           The fitting parameters for the code were determined by 3078100100025 
            using standard monoenerg. gamma-sources.              3078100100026 
MONITOR    ((MONIT1)(90-TH-232(N,G)90-TH-233,,SIG,,MXW)/          3078100100027 
           (79-AU-197(N,G)79-AU-198,,SIG,,MXW))                   3078100100028 
           The ratio of the capture cross section of Th and Au at 3078100100029 
            thermal neutron energy was used as monitor.           3078100100030 
           The values of the thermal neutron capture cross section3078100100031 
           used were: 7.40 +/- 0.08 barn for Th-232               3078100100032 
                      98.8 +/- 0.3  barn for Au-197               3078100100033 
           ((MONIT2)79-AU-197(N,G)79-AU-198,,SIG)                 3078100100034 
MONIT-REF  ((MONIT1),,R,BNL-325,(1),1973)                         3078100100035 
           ((MONIT2),,R,IAEA-227,1983)                            3078100100036 
             The capture cross sections of 197-Au in the keV      3078100100037 
             energy range were taken from standard cross sections 3078100100038 
             recommended by IAEA.                                 3078100100039 
DECAY-DATA (90-TH-233,22.3MIN,DG,459.)                            3078100100040 
DECAY-MON  (79-AU-198-G,2.7D,DG,412.)                             3078100100041 
CORRECTION Measured cross sections were corrected for:            3078100100042 
           1. Multiple scattering and self-shielding effects:     3078100100043 
             ---------------------------------------------------  3078100100044 
               En (keV)       C1                    C2            3078100100045 
             ---------------------------------------------------  3078100100046 
            Thermal maxw      0.97230               1.0562        3078100100047 
                425           0.99995               1.0295        3078100100048 
                480           0.99995               1.0305        3078100100049 
                535           0.99995               1.0310        3078100100050 
                590           0.99995               1.0313        3078100100051 
                615           0.99995               1.0316        3078100100052 
                645           0.99996               1.0319        3078100100053 
                690           0.99996               1.0321        3078100100054 
                740           0.99996               1.0325        3078100100055 
                845           0.99996               1.0333        3078100100056 
                950           0.99997               1.0338        3078100100057 
             ------------ --------------------------------------  3078100100058 
              C1: Self-shielding + multiple scattering correction 3078100100059 
                  factor for Al-foils                             3078100100060 
              C2: Multiple scattering correction factor for Th-   3078100100061 
                  pellet                                          3078100100062 
           2. The effect of the variation of neutron flux as a    3078100100063 
              function of time was taken into consideration.      3078100100064 
              This correction factor was found to be less than 6%.3078100100065 
           3. Second group of neutrons due Ep > 2.4 MeV the       3078100100066 
              estimated error due to this  corr  < +/- 1%.        3078100100067 
           4. The average energy and the spread of the neutron    3078100100068 
              beam for Li target thickness. The neutron spread    3078100100069 
              due this was calcu. to be varying from +/-15 to     3078100100070 
              +/- 25 keV                                          3078100100071 
           5. The energy spread due to the angular spread of      3078100100072 
              neutrons. This was estimated to be about +/- 17 keV.3078100100073 
ERR-ANALYS (ERR-T) Overall uncertainty was estimated (5-6%)       3078100100074 
           (ERR-S,1.,4.) The statistical and fitting error in the 3078100100075 
            determining the photopeak areas of the 459 and 412 keV3078100100076 
            gammas by SAMPO:                     (2-4%) for keV   3078100100077 
                                                (<1%)for thermal  3078100100078 
           (ERR-1,,2.) The uncertainty due the self-shielding and 3078100100079 
            multiple scattering                           (<2%)   3078100100080 
           (ERR-2,,1.) The uncertainty on the thermal capture     3078100100081 
            cross sections of 232-Th and 197-Au:          (<1%)   3078100100082 
CRITIQUE   The present measurements are in good agreement with the3078100100083 
            other recent measurements and deviations are within   3078100100084 
            experimental errors up to En=740keV.                  3078100100085 
STATUS     (TABLE) Table 2 of Ann. Nucl. Energy, 16 (1989) 87     3078100100086 
HISTORY    (19880411C) TMK                                        3078100100087 
           (19890412A) VOF.-Complete revision.                    3078100100088 
           (20090725A) SD: Updated to new date formats,lower case.3078100100089 
            Units and data in COMMON section were corrected,      3078100100090 
            energy was added. Cosmetic changes and codes for      3078100100091 
            partial uncertainties were added.                     3078100100092 
           (20120703U) On. ANALYSIS: Code AREA deleted            3078100100093 
           (20220202A) VT ERR-ANALYS: corrected                   3078100100094 
ENDBIB              92          0                                 3078100100095 
COMMON               2          3                                 3078100100096 
EN-NRM     MONIT1                                                 3078100100097 
EV         NO-DIM                                                 3078100100098 
 0.0253     0.0749                                                3078100100099 
ENDCOMMON            3          0                                 3078100100100 
ENDSUBENT           99          0                                 3078100199999 
SUBENT        30781002   20220202                             32073078100200001 
BIB                  1          1                                 3078100200002 
REACTION   (90-TH-232(N,G)90-TH-233,,SIG)                         3078100200003 
ENDBIB               1          0                                 3078100200004 
NOCOMMON             0          0                                 3078100200005 
DATA                 5         10                                 3078100200006 
EN         EN-RSL     DATA       ERR-T      MONIT2                3078100200007 
KEV        KEV        MB         MB         MB                    3078100200008 
425.       35.        150.       8.         151.4                 3078100200009 
480.       35.        151.       8.         138.                  3078100200010 
535.       35.        166.       9.         127.                  3078100200011 
590.       35.        160.       9.         118.                  3078100200012 
615.       45.        150.       8.         115.                  3078100200013 
645.       35.        167.       9.         108.8                 3078100200014 
690.       45.        164.       9.         102.4                 3078100200015 
740.       45.        170.       9.          96.4                 3078100200016 
845.       45.        175.       9.          87.6                 3078100200017 
950.       45.        162.       9.          84.2                 3078100200018 
ENDDATA             12          0                                 3078100200019 
ENDSUBENT           18          0                                 3078100299999 
ENDENTRY             2          0                                 3078199999999