ENTRY            21733   19840409                             00002173300000001 
SUBENT        21733001   19840409                             00002173300100001 
BIB                 12         24                                 2173300100002 
INSTITUTE  (2JPNTOK) DEPT OF PHYSICS.                             2173300100003 
REFERENCE  (J,NP/A,115,1,6807)                                    2173300100004 
AUTHOR     (K.FUJIKAWA,H.MORINGA)                                 2173300100005 
TITLE      -SEARCH FOR TRI-NEUTRONS -.                            2173300100006 
FACILITY   (CYCLO) CYCLOTRON AT THE INSTITUTE FOR NUCLEAR STUDY   2173300100007 
            OF THE UNIVERSITY OF TOKYO.                           2173300100008 
INC-SOURCE (P-LI7) 55 MEV PROTONS ON NATURAL LITHIUM TARGET.      2173300100009 
INC-SPECT  .BROAD NEUTRON SPECTRUM, WITH A FLUX OF 5 10*8         2173300100010 
            BETWEEN 13.7 AND 19 MEV.                              2173300100011 
SAMPLE     .HIGH PURITY LITHIUM FROURIDE FOR BOTH THE NEUTRON     2173300100012 
            SOURCE AND THE TARGET.                                2173300100013 
METHOD     .THE CROSS SECTION FOR THE (N,3N) REACTION OF LI-7     2173300100014 
            WAS INVESTIGATED USING THE (3N,N) REACTION ON BA-138  2173300100015 
            AS DETECTOR OF TRI-NEUTRONS. THE ACTIVITY OF LA-140   2173300100016 
            WAS MONITORED, AS THE BETA-DECAY PRODUCT OF BA-140.   2173300100017 
            TO AVOID OTHER REACTION PROCESSES SAMPLES OF LIF      2173300100018 
            AND BACO3 OF 99.0 PERCENT PURITY WERE USED.           2173300100019 
DETECTOR   (NAICR) 7.6 CM BY 7.6 CM NAI(TL) SCINTILLATOR AND      2173300100020 
           (GELI ) GE(LI) CRYSTAL FOR COINCIDENCE COUNTING.       2173300100021 
STATUS     .TEXT, PAGES 12 AND 13.                                2173300100022 
HISTORY    (810127C)                                              2173300100023 
           (810213E)                                              2173300100024 
           (840106U) A.P.T. JAPAN CODE CHANGED TO JPN             2173300100025 
           (840106E)                                              2173300100026 
ENDBIB              24          0                                 2173300100027 
NOCOMMON             0          0                                 2173300100028 
ENDSUBENT           27          0                                 2173300199999 
SUBENT        21733002   19810213                             00002173300200001 
BIB                  5         15                                 2173300200002 
REACTION   (3-LI-7(N,3N)3-LI-5,,SIG,,SPA) TRI-NEUTRON PRODUCTION. 2173300200003 
ANALYSIS   .A SOLID ANGLE OF 2 PI IS ASSUMED FOR TRI-NEUTRONS     2173300200004 
            ON BA-138. THE CROSS SECTION ON BA-138 IS CALCULATED  2173300200005 
            USING THE COMPOUND NUCLEUS MODEL OF BLATT AND         2173300200006 
            WEISSKOPF.                                            2173300200007 
STATUS     .TEXT, PAGE 13.                                        2173300200008 
HISTORY    (810127C)                                              2173300200009 
           (810213E)                                              2173300200010 
ERR-ANALYS .THE LARGEST CONTRIBUTION TO THE UNCERTAINTY COMES     2173300200011 
            FROM THE (3N,N) CROSS SECTION OF BA-138, FOR          2173300200012 
            WHICH A VALUE OF 100 MB IS TAKEN. ONE ORDER OF        2173300200013 
            MAGNITUDE IS SUGGESTED AS THE OUTER LIMITS OF         2173300200014 
            UNCERTAINTY ON THIS CROSS SECTION.                    2173300200015 
           .IN COMPARISON THE STATISTICAL COUNTING ERRORS         2173300200016 
            ARE SMALL.                                            2173300200017 
ENDBIB              15          0                                 2173300200018 
NOCOMMON             0          0                                 2173300200019 
DATA                 2          1                                 2173300200020 
EN-DUMMY   DATA-APRX                                              2173300200021 
MEV        MB                                                     2173300200022 
 1.6000E+01 1.0000E+00                                            2173300200023 
ENDDATA              3          0                                 2173300200024 
ENDSUBENT           23          0                                 2173300299999 
ENDENTRY             2          0                                 2173399999999