ENTRY 14687 20210309 14821468700000001 SUBENT 14687001 20210309 14821468700100001 BIB 8 18 1468700100002 TITLE Experiments with a Slow Neutron Velocity Spectrometer 1468700100003 AUTHOR (C.P.Baker,R.F.Bacher) 1468700100004 REFERENCE (J,PR,59,332,1941) 1468700100005 #doi:10.1103/physrev.59.332 1468700100006 INSTITUTE (1USACOR) 1468700100007 FACILITY (CYCLO,1USACOR) 1468700100008 DETECTOR (IOCH) BF3 ionization chamber. 1468700100009 METHOD (TOF) Neutron bursts were produced by modulation of 1468700100010 the arc source of a small cyclotron. Neutrons 1468700100011 subsequently slowed down in paraffin were detected by 1468700100012 a BF3 ionization chamber and linear amplifier. 1468700100013 Modulation of an additional amplifier allowed the 1468700100014 counting of all detected neutrons as well as those 1468700100015 arriving in a specified time interval. Time of flight 1468700100016 experiments were carried out at 3.0 meters with "on" 1468700100017 times of 50 or 100 microsec (microseconds) out of a 1468700100018 period of 2500 microsec. 1468700100019 HISTORY (20210309C) BP 1468700100020 ENDBIB 18 0 1468700100021 NOCOMMON 0 0 1468700100022 ENDSUBENT 21 0 1468700199999 SUBENT 14687002 20210309 14821468700200001 BIB 6 11 1468700200002 REACTION (48-CD-0(N,TOT),,SIG) 1468700200003 SAMPLE Thin cadmium, 0.052 g/cm2. 1468700200004 METHOD 3 meters source detector distance. 1468700200005 ERR-ANALYS (ERR-S) The statistical accuracy of each point is 1468700200006 about 10 percent in the measurement of the 1468700200007 transmission. 1468700200008 CORRECTION No correction has been applied for the possible 1468700200009 effect of the resolution of the apparatus or the 1468700200010 effect of delayed emission of thermal neutrons, both 1468700200011 of which are discussed later. 1468700200012 STATUS (CURVE) Fig. 11, page 340. 1468700200013 ENDBIB 11 0 1468700200014 COMMON 1 3 1468700200015 ERR-S 1468700200016 PER-CENT 1468700200017 10.0 1468700200018 ENDCOMMON 3 0 1468700200019 DATA 2 21 1468700200020 EN DATA 1468700200021 EV B 1468700200022 0.249 2239.074 1468700200023 0.272 2351.358 1468700200024 0.292 1777.179 1468700200025 0.314 2069.409 1468700200026 0.336 2296.133 1468700200027 0.356 2915.445 1468700200028 0.399 2698.833 1468700200029 0.410 3188.266 1468700200030 0.421 2958.367 1468700200031 0.431 3202.573 1468700200032 0.442 4215.212 1468700200033 0.452 5309.593 1468700200034 0.464 4997.782 1468700200035 0.474 5094.909 1468700200036 0.484 3916.858 1468700200037 0.495 1577.955 1468700200038 0.506 1397.101 1468700200039 0.517 644.053 1468700200040 0.527 610.392 1468700200041 0.539 609.201 1468700200042 0.549 36.099 1468700200043 ENDDATA 23 0 1468700200044 ENDSUBENT 43 0 1468700299999 SUBENT 14687003 20210309 14821468700300001 BIB 6 11 1468700300002 REACTION (48-CD-0(N,TOT),,SIG) 1468700300003 SAMPLE Thin cadmium, 0.052 g/cm2. 1468700300004 METHOD 1.5 meters source detector distance. 1468700300005 ERR-ANALYS (ERR-S) The statistical accuracy of each point is 1468700300006 about 10 percent in the measurement of the 1468700300007 transmission. 1468700300008 CORRECTION No correction has been applied for the possible 1468700300009 effect of the resolution of the apparatus or the 1468700300010 effect of delayed emission of thermal neutrons, both 1468700300011 of which are discussed later. 1468700300012 STATUS (CURVE) Fig. 11, page 340. 1468700300013 ENDBIB 11 0 1468700300014 COMMON 1 3 1468700300015 ERR-S 1468700300016 PER-CENT 1468700300017 10.0 1468700300018 ENDCOMMON 3 0 1468700300019 DATA 2 18 1468700300020 EN DATA 1468700300021 EV B 1468700300022 -0.022 3491.118 1468700300023 0.024 3813.664 1468700300024 0.065 2796.149 1468700300025 0.108 2939.203 1468700300026 0.150 3114.953 1468700300027 0.151 2886.018 1468700300028 0.235 2109.590 1468700300029 0.236 1929.701 1468700300030 0.257 2352.719 1468700300031 0.279 1729.381 1468700300032 0.300 3133.418 1468700300033 0.321 2788.060 1468700300034 0.344 1265.444 1468700300035 0.365 2146.275 1468700300036 0.386 2160.582 1468700300037 0.428 3399.038 1468700300038 0.449 5195.381 1468700300039 0.460 5308.799 1468700300040 ENDDATA 20 0 1468700300041 ENDSUBENT 40 0 1468700399999 SUBENT 14687004 20210309 14821468700400001 BIB 5 13 1468700400002 REACTION (48-CD-0(N,TOT),,TRN) 1468700400003 SAMPLE Thick cadmium, 0.45 g/cm2. 1468700400004 ERR-ANALYS (ERR-S,10.,25.) The statistical accuracy above 0.4 eV 1468700400005 is 10 percent but at lower energy it was decreased 1468700400006 because of the long time involved in taking accurate 1468700400007 data where the transmission is low. At 0.21 eV the 1468700400008 error is 15 percent and the lowest energy point has a 1468700400009 statistical error of 25 percent. 1468700400010 CORRECTION No correction for delayed emission of thermal 1468700400011 neutrons need be considered for these data as the 1468700400012 energy range is above that where the thermal 1468700400013 distribution plays an important role. 1468700400014 STATUS (CURVE) Fig. 12, page 341. 1468700400015 ENDBIB 13 0 1468700400016 COMMON 1 3 1468700400017 THICKNESS 1468700400018 G/CM-SQ 1468700400019 0.45 1468700400020 ENDCOMMON 3 0 1468700400021 DATA 2 10 1468700400022 EN DATA 1468700400023 EV NO-DIM 1468700400024 0.285 0.016 1468700400025 0.502 0.021 1468700400026 0.719 0.050 1468700400027 0.943 0.123 1468700400028 1.151 0.297 1468700400029 1.374 0.503 1468700400030 1.586 0.737 1468700400031 1.803 0.707 1468700400032 2.015 0.941 1468700400033 2.016 0.807 1468700400034 ENDDATA 12 0 1468700400035 ENDSUBENT 34 0 1468700499999 SUBENT 14687005 20210309 14821468700500001 BIB 3 9 1468700500002 REACTION 1(48-CD-0(N,0),,EN) 1468700500003 2(48-CD-0(N,TOT),,SIG,,RES) 1468700500004 3(48-CD-0(N,TOT),,WID) 1468700500005 4(48-CD-0(N,EL),,WID) 1468700500006 ANALYSIS From the cross section at resonance (1+-((1/2i)+1)) 1468700500007 Gamman, Gamman was found to be 5x10-4 eV. In this 1468700500008 calculation 13 percent abundance of the effective 1468700500009 isotope was assumed. 1468700500010 STATUS (TABLE) page 346. 1468700500011 ENDBIB 9 0 1468700500012 NOCOMMON 0 0 1468700500013 DATA 4 1 1468700500014 DATA 1DATA 2DATA 3DATA 4 1468700500015 EV B EV EV 1468700500016 0.14 5400.0 0.12 5.0E-04 1468700500017 ENDDATA 3 0 1468700500018 ENDSUBENT 17 0 1468700599999 ENDENTRY 5 0 1468799999999