ENTRY 21819 19830801 00002181900000001 SUBENT 21819001 19830801 00002181900100001 BIB 15 83 2181900100002 INSTITUTE (2SWDLND) UNIVERSITY OF LUND. 2181900100003 REFERENCE (C,82ANTWER,,866,8209) 2181900100004 AUTHOR (P.ANDERSSON,R.ZORRO,I.BERQVIST) 2181900100005 TITLE -ON NEUTRON CAPTURE CROSS SECTION MEASUREMENTS 2181900100006 WITH THE ACTIVATION TECHNIQUE IN THE MEV 2181900100007 REGION.- 2181900100008 FACILITY (VDG,2SWDLND) 3 MV TANDEM VAN DE GRAAFF. 2181900100009 INC-SOURCE (P-T ) PROTON-TRITIUM REACTION AND 2181900100010 (D-T ) DEUTERON-TRITIUM REACTION. 2181900100011 THE PROTONS AND THE DEUTERONS WERE ACCELERATED 2181900100012 BY THE VAN DE GRAAFF MACHINE. 2181900100013 SEVERAL TARGETS WERE USED AND INVESTIGATED WITH 2181900100014 RESPECT TO THE PRIMARY NEUTRON BACKGROUND. 2181900100015 - THIN TITANIUM LAYERS, ABOUT 2 MG/CM**2 2181900100016 THICKNESS IN WHICH THE DEUTERIUM OR TRITIUM 2181900100017 WAS ABSORBED, EAVAPORATED ONTO A 0.5 MM 2181900100018 THICK BACKING. IT WAS SHOWN THAT THE TI(T) 2181900100019 CANNOT BE USED ANYMORE BEYOND 4.5 MEV 2181900100020 NEUTRON ENERGY, AND THAT DEUTERIUM TARGETS 2181900100021 ARE PREFERABLE ABOVE 3.0 MEV. THE ENERGY 2181900100022 RANGE CAN THAN BE EXTENDED BY 1. MEV. 2181900100023 - DEUTERIUM GAS TARGET WITH A 4.2 MG/CM**2 2181900100024 THICK MO-FOIL AS ENTRANCE WINDOW AND GOLD 2181900100025 AS A BEAM STOP. THIS WAY THE NEUTRON ENERGY 2181900100026 RANGE CAN BE EXTENDED BY SEVERAL MEV. 2181900100027 - ALSO A T(ZR-90) TARGET WITH NATURAL ZR 2181900100028 HAS BEEN TESTED. 2181900100029 SAMPLE .PLACED AT DISTANCES SUCH THAT THE SOLID ANGLE 2181900100030 SUBTENDED BY THE SAMPLES AT THE TARGET WAS THE 2181900100031 SAME IN ALL CASES. FOR THE STUDIES OF THE 2181900100032 THICKNESS DEPENDENCE OF THE ACTIVATION YIELDS, 2181900100033 INDIUM SAMPLES WERE USED WITH A DIAMETER OF 10. 2181900100034 MM AND A THICKNESS RANGING FROM 0.18 TO 1.66 2181900100035 GRAMS/CM**2. THE TARGET-SAMPLE DISTANCE DEPENDENCE 2181900100036 WAS DETERMINED USING 0.6 GRAMS/CM**2 SAMPLES WITH 2181900100037 DIAMETERS RANGING FROM 5.0 TO 20. MM. 2181900100038 METHOD .ACTIVATION. 2181900100039 .DEPENDENCE OF THE ACTIVATION YIELDS ON SAMPLE 2181900100040 THICKNESS AND EFFECTIVE TARGET-SAMPLE DISTANCE 2181900100041 HAS BEEN INVESTIGATED TO ALLOW DETAILED 2181900100042 CORRECTIONS. 2181900100043 DETECTOR (LONGC) TO MONITOR THE NEUTRON FLUX. AT 1.2 M 2181900100044 FROM THE TARGET. 2181900100045 (GELI ) 80 CC OPEN END GE(LI) DETECTOR. THE 2181900100046 RELATIVE EFFICIENCY WAS DETERMINED WITH A 2181900100047 EU-152 SOURCE. 2181900100048 MONITOR (49-IN-115(N,INL)49-IN-115-M,,SIG) 2181900100049 PART-DET (DG ) DECAY-GAMMAS. 2181900100050 STATUS .DATA TAKEN FROM MAIN REFERENCE. 2181900100051 HISTORY (830121C) G.C. 2181900100052 (830210E) 2181900100053 (830314A) A.P.T. UNITS IN SUBWORK 002 CORRECTED. 2181900100054 (830322E) 2181900100055 (830610A) BN. ABUNDANCE IN SE 002 CORRECTED. 2181900100056 (830801E) 2181900100057 CORRECTION .PRIMARY NEUTRON BACKGROUND, I.E. NEUTRONS 2181900100058 PRODUCED BY (P,N) AND (D,N) REACTIONS IN THE 2181900100059 TARGET BACKING AND ABSORPTION MATERIALS AND 2181900100060 IN THE APERTURES ALONG THE BEAM LINE. THIS WAS 2181900100061 DONE BY USING TARGETS WITH NATURAL HYDROGEN 2181900100062 IN STEAD OF D OR T. (EMPTY TARGETS). 2181900100063 .SECONDARY NEUTRON BACKGROUND. IT CONSISTS OF 2181900100064 SEVERAL CONTRIBUTIONS , 2181900100065 - NEUTRONS PRODUCED BY INELASTIC SCATTERING 2181900100066 IN THE SAMPLE. THIS WAS CORRECTED FOR BY 2181900100067 STUDYING THE ACTIVATION YIELD AS A FUNCTION 2181900100068 OF THE SAMPLE THICKNESS. 2181900100069 - NEUTRONS PRODUCED BY INELASTIC SCATTERING 2181900100070 IN STRUCTURAL MATERIALS NEAR THE TARGET- 2181900100071 SAMPLE ASSEMBLY AND NEUTRONS SCATTERED BY 2181900100072 THE WALLS OF THE ROOM. THIS WAS CORRECTED 2181900100073 FOR BY THE STUDYING THE ACTIVATION YIELD 2181900100074 AS A FUNCTION OF THE TARGET-SAMPLE DISTANCE. 2181900100075 BOTH EFFECTS PRODUCE NEUTRONS WITH LOWER 2181900100076 ENERGIES WITH HIGHER (N,G) CROSS SECTIONS 2181900100077 AND ARE THUS IMPORTANT. 2181900100078 ERR-ANALYS (ERR-T) TOTAL ERROR GIVEN. 2181900100079 IT CONSISTS OF THE FOLLOWING CONTRIBUTIONS , 2181900100080 (ERR-S) STATISTICAL UNCERTAINTIES , 4-5 PERC. 2181900100081 (MONIT-ERR) 6 PERCENT. 2181900100082 (ERR-1) RELATIVE DETECTION EFFICIENCY, 2 PERC. 2181900100083 (ERR-2) GAMMA-RAY CORRECTION FACTORS, 2 PERC. 2181900100084 (ERR-3) DECAY- AND BRANCHING RATIOS, 2 PERC. 2181900100085 ENDBIB 83 0 2181900100086 COMMON 4 3 2181900100087 ERR-S ERR-1 ERR-2 ERR-3 2181900100088 PER-CENT PER-CENT PER-CENT PER-CENT 2181900100089 5.0000E+00 2.0000E+00 2.0000E+00 2.0000E+00 2181900100090 ENDCOMMON 3 0 2181900100091 ENDSUBENT 90 0 2181900199999 SUBENT 21819002 19861015 00002181900200001 BIB 5 14 2181900200002 REACTION (49-IN-115(N,G)49-IN-116-M1,M+,SIG) 2181900200003 DECAY-DATA (49-IN-116-M1,3247.SEC,DG,1293.54,0.85) 2181900200004 DECAY-MON (49-IN-115-M,16150.SEC,DG,336.0,0.459) 2181900200005 STATUS .DATA TAKEN FROM TABLE 2 OF MAIN REFERENCE. 2181900200006 THE UNITS OF THE INCIDENT NEUTRON ENERGY ARE 2181900200007 MISPRINTED AS 'KEV' INSTEAD OF 'MEV'. 2181900200008 HISTORY (830121C) G.C. 2181900200009 (830210E) 2181900200010 (830314A) A.P.T. NEUTRON ENERGY UNIT HEADING CORRECTED.2181900200011 (830322E) 2181900200012 (830610A) BN. ABUNDANCE CORRECTED 2181900200013 (830801E) 2181900200014 (860808A)HH REACTION/DECAY DATA STRING CORRECTED 2181900200015 (860807E) 2181900200016 ENDBIB 14 0 2181900200017 NOCOMMON 0 0 2181900200018 DATA 5 17 2181900200019 EN DATA ERR-T MONIT MONIT-ERR 2181900200020 MEV MB PER-CENT MB PER-CENT 2181900200021 1.9600E+00 1.3200E+02 6.8000E+00 2.6200E+02 6.1000E+00 2181900200022 2.0600E+00 1.3200E+02 6.9000E+00 2.8700E+02 6.1000E+00 2181900200023 2.1600E+00 1.2600E+02 6.8000E+00 3.1300E+02 6.0000E+00 2181900200024 2.2100E+00 1.2700E+02 6.8000E+00 3.1900E+02 6.0000E+00 2181900200025 2.2600E+00 1.1900E+02 6.8000E+00 3.2300E+02 6.0000E+00 2181900200026 2.3500E+00 1.0200E+02 6.8000E+00 3.3000E+02 6.0000E+00 2181900200027 2.4500E+00 7.5400E+01 6.7000E+00 3.3600E+02 6.0000E+00 2181900200028 2.6800E+00 6.0000E+01 6.9000E+00 3.4300E+02 6.0000E+00 2181900200029 2.9300E+00 4.7000E+01 6.9000E+00 3.4800E+02 6.0000E+00 2181900200030 3.1700E+00 3.9000E+01 8.2000E+00 3.4800E+02 7.3000E+00 2181900200031 3.4200E+00 3.2900E+01 8.1000E+00 3.4100E+02 7.3000E+00 2181900200032 3.6800E+00 2.6300E+01 7.7000E+00 3.3600E+02 6.0000E+00 2181900200033 3.8600E+00 2.2400E+01 7.7000E+00 3.2800E+02 6.0000E+00 2181900200034 4.0600E+00 2.0400E+01 8.0000E+00 3.2700E+02 6.0000E+00 2181900200035 4.2100E+00 1.7300E+01 8.0000E+00 3.2500E+02 6.0000E+00 2181900200036 4.3600E+00 1.5500E+01 7.9000E+00 3.2100E+02 6.0000E+00 2181900200037 4.4600E+00 1.3200E+01 1.5200E+01 3.2100E+02 6.0000E+00 2181900200038 ENDDATA 19 0 2181900200039 ENDSUBENT 38 0 2181900299999 ENDENTRY 2 0 2181999999999