ENTRY 11191 20210317 14831119100000001 SUBENT 11191001 20210317 14831119100100001 BIB 10 36 1119100100002 TITLE Neutron Beam Spectrometer Studies of Boron, Cadmium, 1119100100003 and the Energy Distribution from Paraffin 1119100100004 AUTHOR (J.Rainwater,W.W.Havens Jr) 1119100100005 REFERENCE (J,PR,70,136,1946) 1119100100006 #doi:10.1103/PhysRev.70.136 1119100100007 REL-REF (O,11685001,L.J.Rainwater+,J,PR,71,65,1947) Cd data. 1119100100008 INSTITUTE (1USACOL) 1119100100009 FACILITY (CYCLO,1USACOL) The Columbia Neutron Velocity 1119100100010 Spectrometer. 1119100100011 DETECTOR (BF3) BF3 proportional counter detectors. 1119100100012 METHOD (TOF) Neutrons slowed down in paragon are detected by 1119100100013 BF3 proportional counters. Excellent collimation is 1119100100014 obtained by using an extensive B4C and Cd collimating 1119100100015 system. Experiments were conducted principally at a 1119100100016 5.4-meter source detector distance. A special 1119100100017 selector system counts all the neutrons detected and 1119100100018 also selectively counts those detected in an 1119100100019 adjustable timed interval after the cyclotron burst. 1119100100020 The slow neutron energy distributions from paraffin 1119100100021 "source" slabs were shown to be of a modified 1119100100022 Maxwellian form with an asymmetrical high energy tail. 1119100100023 COMMENT Compiler's comment: Plots were digitized vs. neutron 1119100100024 time of flight in microsec/meter and converted to 1119100100025 energy by compiler using the relation 1119100100026 E = (72.3/t)**2 eV which gives the neutron 1119100100027 energy for a timing t, microsec/meter from. Formula 1119100100028 was taken from Phys. Rev. 71, 165 (1947) and verified 1119100100029 using the method of visual inspection. Transmission 1119100100030 data are more reliable, while cross section scale is 1119100100031 less obvious. 1119100100032 HISTORY (19760924T) Translated from SCISRS. 1119100100033 (19800814A) Converted to reaction formalism. 1119100100034 (20210317A) BP: Updated to new date formats, lower 1119100100035 case. corrections according last EXFOR rules and 1119100100036 Dict. Added method, detectors, doi and updated the 1119100100037 data subentry, digitized data. Subentry 3 was added. 1119100100038 ENDBIB 36 0 1119100100039 NOCOMMON 0 0 1119100100040 ENDSUBENT 39 0 1119100199999 SUBENT 11191002 20210317 14831119100200001 BIB 5 10 1119100200002 REACTION (5-B-0(N,TOT),,SIG) 1119100200003 SAMPLE A 2.464 g/cm2 sample of B203 was used. 1119100200004 METHOD For the highest energy measurements the cyclotron and 1119100200005 detection on time intervals were reduced to about 15 1119100200006 microseconds each to give a total resolution width of 1119100200007 about 6 microseconds/meter. 1119100200008 STATUS (CURVE) Fig. 10, page 152. Digitizing is based on time 1119100200009 of flight, converted to energy by compiler. 1119100200010 HISTORY (20210317A) BP: Added sample, resolution. Changed old 1119100200011 BNL-325 curve with digitization. 1119100200012 ENDBIB 10 0 1119100200013 NOCOMMON 0 0 1119100200014 DATA 2 3 1119100200015 EN DATA 1119100200016 EV B 1119100200017 259.636 7.362 1119100200018 76.301 12.815 1119100200019 36.246 19.728 1119100200020 ENDDATA 5 0 1119100200021 ENDSUBENT 20 0 1119100299999 SUBENT 11191003 20210414 14831119100300001 BIB 6 23 1119100300002 REACTION (5-B-0(N,TOT),,SIG) 1119100300003 SAMPLE A 2.464 g/cm2 sample of B203 was used. 1119100300004 METHOD For the measurements below 100 microseconds/meter the 1119100300005 total resolution width was 20 microseconds/meter plus 1119100300006 3.7 percent of the time-of-flight due to the counter 1119100300007 length. For the remainder of the measurements a 5000- 1119100300008 microsecond cycle was used with cyclotron and 1119100300009 detection, on-time widths of 100 microseconds each 1119100300010 below 500 microseconds/meter and 150 microseconds 1119100300011 each above 500 microseconds/meter. In calculating the 1119100300012 total resolution width above 200 microseconds/meter 1119100300013 the delayed thermal emission width of 45 microseconds 1119100300014 and the 3.7 percent effect due to the counter length 1119100300015 must be added to the sum of the cyclotron and 1119100300016 detection on-time intervals. 1119100300017 ANALYSIS The results of these measurements together with an 1119100300018 estimate of the overall uncertainty present may be 1119100300019 given as: sigma = [(118+-4)*E**(-1/2)]*10**(-24) 1119100300020 cm2/atom, where E is the neutron energy in electron 1119100300021 volts. 1119100300022 STATUS (CURVE) Fig. 11, page 152. Digitizing is based on time 1119100300023 of flight, converted to energy by compiler. 1119100300024 HISTORY (20210317C) BP 1119100300025 ENDBIB 23 0 1119100300026 NOCOMMON 0 0 1119100300027 DATA 2 19 1119100300028 EN DATA 1119100300029 EV B 1119100300030 104.282 465.252 1119100300031 46.356 517.936 1119100300032 7.416 482.768 1119100300033 5.150 530.214 1119100300034 1.984 565.316 1119100300035 1.156 582.839 1119100300036 0.902 616.203 1119100300037 0.724 668.868 1119100300038 0.594 721.555 1119100300039 0.514 702.201 1119100300040 0.297 716.248 1119100300041 0.220 747.849 1119100300042 0.146 804.060 1119100300043 0.099 835.676 1119100300044 0.077 858.470 1119100300045 0.070 905.869 1119100300046 0.060 976.121 1119100300047 0.056 1025.253 1119100300048 0.054 1098.968 1119100300049 ENDDATA 21 0 1119100300050 ENDSUBENT 49 0 1119100399999 ENDENTRY 3 0 1119199999999