ENTRY            20663   19840127                             00002066300000001 
SUBENT        20663001   19840127                             00002066300100001 
BIB                 16         97                                 2066300100002 
INSTITUTE  (2GERKFK) INSTITUT FUER NEUTRONENPHYSIK UND REAKTOR-   2066300100003 
            TECHNIK.                                              2066300100004 
REFERENCE  (R,KFK-2191,,750806)ALSO AS THESIS ACCEPTED AT THE     2066300100005 
            FACULTY FOR ENGINEERING OF THE UNIVERSITY OF          2066300100006 
            KARLSRUHE.                                            2066300100007 
           (J,NSE,61,(4),471,7612)                                2066300100008 
AUTHOR     (C.S.YEN)                                              2066300100009 
TITLE      -MEASUREMENTS OF THE RATIO OF THE CROSS SECTIONS OF    2066300100010 
            235-U FOR CAPTURE AND FISSION IN THE NEUTRON ENERGY   2066300100011 
            RANGE 200 EV TO 20 KEV-                               2066300100012 
FACILITY   (CCW  ) COCKCROFT-WALTON-TYPE ACCELERATOR (150 KV,50   2066300100013 
            MICROAMP AT A PULSELENGTH OF 0.5 MICROSEC AND         2066300100014 
            625 PPS REPETITIONRATE) USED FOR MAIN EXPERIMENT.     2066300100015 
           .THE EXPERIMENTAL REACTOR STARK OF THE INSTITUTE WAS   2066300100016 
            USED FOR THE CALIBRATION MEASUREMENTS.                2066300100017 
INC-SOURCE (D-T  ) WITH THE REACTION 3H(D,N)4HE 14 MEV NEUTRONS   2066300100018 
            WERE CREATED IN A TRITIUM-TITANIUM TARGET.            2066300100019 
           (THCOL) THE THERMAL COLUMN OF THE EXPERIMENTAL         2066300100020 
            REACTOR STARK OF THE INSTITUT FUER NEUTRONENPHYSIK    2066300100021 
            UND REAKTORTECHIK (5 W CONSTANT POWER) SUPPLIED THE   2066300100022 
            FLUX FOR THE CALIBRATION OF THE FISSION DETECTOR.     2066300100023 
SAMPLE     .FOR THE SUM-MEASUREMENT U-235 FOILS (3.57,8.92,       2066300100024 
            17.84X10E+20 ATOMS/CM2,93.5PC U-235) WERE PLACED AS   2066300100025 
            ZYLINDERS AROUND THE PROPORTIONAL COUNTER.            2066300100026 
           .SAMPLE AND DETECTOR FOR THE FISSION REACTION WERE     2066300100027 
            ONE AND THE SAME.                                     2066300100028 
METHOD     (SLODT) A SLOWING DOWN TIME SPECTROMETER IN THE FORM   2066300100029 
            OF A PB-PILE(2X2X2M3,99.99PC PURITY) IN CONNECTION    2066300100030 
            WITH THE COCKCROFT-WALTON ACCELERATOR WAS USED TO     2066300100031 
            CREATE A SLOW FLUX (200 EV TO 20 KEV).ENERGY-         2066300100032 
            DETERMINATION WAS ACHIEVED FROM THE MEASUREMENT OF    2066300100033 
            THE SLOWING-DOWN-TIME.                                2066300100034 
           .DETAILED DESCRIPTION SEE REFERENCE.                   2066300100035 
DETECTOR   (PROPC) A GAMMA-PROPORTIONAL COUNTER WAS USED TO       2066300100036 
            MEASURE THE SUM OF FISSION AND CAPTURE EVENTS.        2066300100037 
           .IT WAS EMBEDDED IN THE SAMPLES.                       2066300100038 
           .THE CYLINDRICAL COUNTER CONSISTED OF ALMG3 OF A       2066300100039 
            THICKNESS OF 5.5MM WITH A TUNGSTEN ANODE (DIAMETER    2066300100040 
            50 MICRON).IT WAS FILLED WITH 1.5 BAR ARGON AND       2066300100041 
            0.02 BAR CO2.THE OUTER DIAMETER WAS 27MM, LENGTH      2066300100042 
            370MM, HIGHEST OPERATING VOLTAGE 2500V.               2066300100043 
           .THE EFFICIENCY WAS DETERMINED BY CALIBRATED GAMMA-    2066300100044 
            SOURCES FROM THE RADIOCHEMICAL CENTRE,AMERSHAM,       2066300100045 
            ENGLAND,AND WITH THE HELP OF A 24NA-SOURCE, CREATED   2066300100046 
            BY IRRADIATION OF 23NA FROM THE THERMAL COLUMN OF     2066300100047 
            THE EXPERIMENTAL REACTOR FR2.                         2066300100048 
           (FISCH) 2 FISSION CHAMBERS(U-235,ARGON) WERE USED, TO  2066300100049 
            DETERMINE THE FISSION EVENT RATE.                     2066300100050 
           .CALIBRATION IN THE THERMAL FLUX OF STARK.             2066300100051 
           .THERMAL FLUX FOR CALIBRATION MONITORED BY A U-235,    2066300100052 
            ARGON-FILLED FISSION CHAMBER.                         2066300100053 
           .U-238 FISSION CHAMBER TO MONITOR THE TIME-DEPENDENT   2066300100054 
            BEHAVIOUR OF NEUTRON PRODUCTION.                      2066300100055 
           .BF3-COUNTOR TO MONITOR THE FLUX IN THE VICINITY OF    2066300100056 
            THE SAMPLE.                                           2066300100057 
ANALYSIS   .AS NORMALIZING STANDARD FOR THE MEASUREMENT OF THE    2066300100058 
            FISSION RATE (EFFICIENCY OF FISSION CHAMBER) A        2066300100059 
            MEASUREMENT IN THERMAL REACTORFLUX WAS UNDERTAKEN     2066300100060 
            AND THE NECESSARY THERMAL FISSION AND CAPTURE CROSS   2066300100061 
            SECTIONS TAKEN FROM TABULATIONS (REF. NOT GIVEN).     2066300100062 
           .ENERGY SPECTRUM DEDUCED FROM SLOWING DOWN TIME        2066300100063 
            SPECTRUM.TIME AND SPACE DEPENDENT NEUTRON FLUX        2066300100064 
            DETERMINED VIA INSTATIONARY ENERGY-DEPENDENT          2066300100065 
            TRANSPORT THEORY, DIFFUSION THEORY AND FERMI-AGE      2066300100066 
            THEORY.                                               2066300100067 
           .THE NECESSARY CONSTANTS HAVE BEEN DETERMINED BY       2066300100068 
            EITHER MONTE-CARLO CALCULATIONS OR EXPERIMENTALLY.    2066300100069 
           .FOR DETAILS SEE REFERENCE.                            2066300100070 
PART-DET   (G    ) GAMMAS DETECTED BY PROPORTIONAL COUNTERS TO    2066300100071 
            GIVE THE NUMBER OF FISSION AND CAPTURE EVENTS.        2066300100072 
           (N    ) FISSION RATE WAS DETERMINED BY USE OF A        2066300100073 
            NEUTRON DETECTING FISSION CHAMBER.                    2066300100074 
COMMENT    .SYSTEMATIC ERROR POSSIBLE,SINCE ANALYSIS WAS CARRIED  2066300100075 
            OUT UNDER THE ASSUMPTION, THAT THE MEAN PROMPT        2066300100076 
            GAMMA-ENERGY PER FISSION IS INDEPENDENT OF THE        2066300100077 
            NEUTRON-ENERGY.                                       2066300100078 
STATUS     .ALPHA VALUES TAKEN FROM REFERENCE.                    2066300100079 
HISTORY    (761012C)                                              2066300100080 
           (770504E)                                              2066300100081 
           (810112A) ERR-COLUMNS CHANGED.                         2066300100082 
           (810120E)                                              2066300100083 
CORRECTION .FOR CALIBRATION MEASUREMENTS                          2066300100084 
            DELAYED FISSION GAMMAS,                               2066300100085 
            NATURAL ACTIVITY OF THE URANIUM,                      2066300100086 
            ACTIVITY DUE TO THE CREATION OF                       2066300100087 
            FISSION PRODUCTS FROM PREVIOUS IRRADIATIONS.          2066300100088 
           .FOR THE MAIN EXPERIMENT                               2066300100089 
            NATURAL RADIOACTIVITY,                                2066300100090 
            ACTIVATION DURING DURATION OF EXPERIMENT,             2066300100091 
            NEUTRONS FROM PREVIOUS BEAM BURSTS,(LESS THAN 1 PC),  2066300100092 
            CAPTURE-GAMMA-RAYS IN PILE AND COUNTER,               2066300100093 
            SELF-ABSORPTION,                                      2066300100094 
            DEAD-TIME OF ANALYZER (16 MICROSEC,4PC CORRECTION),   2066300100095 
            NEUTRON SCATTERING IN THE GAMMA-COUNTER.              2066300100096 
ERR-ANALYS (ERR-S) STATISTICAL ERRORS- LESS THAN 1 PC.            2066300100097 
           (ERR-T) TOTAL ERRORS BETWEEN 13 AND 20 PC.             2066300100098 
           .ERROR IN CALIBRATION- 3.2 PC(80PC OF TOTAL).          2066300100099 
ENDBIB              97          0                                 2066300100100 
NOCOMMON             0          0                                 2066300100101 
ENDSUBENT          100          0                                 2066300199999 
SUBENT        20663002   19840127                             00002066300200001 
BIB                  3          7                                 2066300200002 
REACTION   (92-U-235(N,ABS),,ALF)                                 2066300200003 
COMMENT    .THE ENERGY RESOLUTION IS 25 PC AT 200 EV AND 50 PC    2066300200004 
            AT 20 KEV.                                            2066300200005 
HISTORY    (761021C)                                              2066300200006 
           (770504E)                                              2066300200007 
           (810112A)                                              2066300200008 
           (810120E)                                              2066300200009 
ENDBIB               7          0                                 2066300200010 
NOCOMMON             0          0                                 2066300200011 
DATA                 4         24                                 2066300200012 
EN         DATA       ERR-T      ERR-S                            2066300200013 
KEV        NO-DIM     NO-DIM     NO-DIM                           2066300200014 
 2.0000E-01 7.6000E-01 1.0000E-01                                 2066300200015 
 2.5000E-01 7.0000E-01            3.0000E-02                      2066300200016 
 3.0000E-01 7.2000E-01            3.0000E-02                      2066300200017 
 3.5000E-01 7.1000E-01            3.0000E-02                      2066300200018 
 4.1000E-01 6.1000E-01            3.0000E-02                      2066300200019 
 4.7000E-01 5.7000E-01            5.0000E-02                      2066300200020 
 5.6000E-01 3.6000E-01            4.0000E-02                      2066300200021 
 6.1000E-01 3.8000E-01            5.0000E-02                      2066300200022 
 7.0000E-01 4.8000E-01            5.0000E-02                      2066300200023 
 7.9000E-01 5.3000E-01            5.0000E-02                      2066300200024 
 9.1000E-01 5.8000E-01            5.0000E-02                      2066300200025 
 1.0500E+00 5.8000E-01            3.0000E-02                      2066300200026 
 1.2800E+00 5.1000E-01            3.0000E-02                      2066300200027 
 1.5400E+00 4.5000E-01            6.0000E-02                      2066300200028 
 1.8500E+00 4.7000E-01            5.0000E-02                      2066300200029 
 2.1100E+00 4.5000E-01            3.0000E-02                      2066300200030 
 2.6800E+00 4.2000E-01            3.0000E-02                      2066300200031 
 3.3700E+00 3.3000E-01            3.0000E-02                      2066300200032 
 4.2300E+00 3.8000E-01            4.0000E-02                      2066300200033 
 5.1700E+00 3.5000E-01            2.0000E-02                      2066300200034 
 6.3300E+00 3.6000E-01            2.0000E-02                      2066300200035 
 7.8200E+00 3.6000E-01            2.0000E-02                      2066300200036 
 9.3500E+00 3.7000E-01            2.0000E-02                      2066300200037 
 1.2760E+01 3.3000E-01 7.0000E-02                                 2066300200038 
ENDDATA             26          0                                 2066300200039 
ENDSUBENT           38          0                                 2066300299999 
ENDENTRY             2          0                                 2066399999999