ENTRY 13789 20120715 13851378900000001 SUBENT 13789001 20120715 13851378900100001 BIB 13 39 1378900100002 INSTITUTE (1USABRK) 1378900100003 REFERENCE (J,PR,55,339,19390215) 1378900100004 AUTHOR (W.F.Libby,E.A.Long) 1378900100005 TITLE The Scattering of slow neutrons by gaseous ortho- and 1378900100006 parahydrogen: spin dependence of the neutron-proton 1378900100007 force. 1378900100008 SAMPLE Ortho- and parahydrogen gas contained in a cylindrical 1378900100009 copper bomb. Liquid air used to keep the gas at 90 K. 1378900100010 A pressure line for up to several hundred atmospheres 1378900100011 connected the bomb to the storage hydrogen tank and a 1378900100012 calibrated pressure gauge. 1378900100013 INC-SOURCE (RA-BE) 200 mg of radium as bromide mixed with 10 g of 1378900100014 powdered beryllium metal. Paraffin used as a moderator1378900100015 for the work with room temperature neutrons. Neutrons 1378900100016 obtained through the walls of Dewar vessel surrounding1378900100017 Ra-Be source and containing a cylinder of paraffin 1378900100018 immersed in liquid air. 1378900100019 METHOD (TRN) Transmission. 1378900100020 Parahydrogen gas obtained after 24 hour conversion 1378900100021 by placing a few hundred cc charcoal in about eight 1378900100022 liters of liquid normal hydrogen in a Dewar surrounded1378900100023 by a liquid air. The gas analyses were made by the 1378900100024 heat conductivity method of Bonhoeffer. 1378900100025 DETECTOR (BF3) Boron Trifluoride neutron detector. The distances1378900100026 from the scatterer to the source and to the counter 1378900100027 were each about 25 cm. 1378900100028 ANALYSIS Cross sections calculated from measured transmission 1378900100029 by converting pressures into number of H2 molecules 1378900100030 in the beam using the perfect gas laws. 1378900100031 CORRECTION Results corrected for scattering into counter of 1378900100032 neutrons that would have missed it if scatterer had 1378900100033 not been present. Correction calculated assuming 1378900100034 isotropic scattering and checked experimentally by 1378900100035 measuring scattering cross sections of ethane, 1378900100036 ethylene, and methane in apparatus. 1378900100037 ERR-ANALYS (DATA-ERR) Absolute uncertainties given. 1378900100038 STATUS (TABLE) Data taken from Table I of PR,55,339,1939 1378900100039 HISTORY (20020710C) IS 1378900100040 (20120714U) SD:BIB update according to last EXFOR rules1378900100041 ENDBIB 39 0 1378900100042 COMMON 1 3 1378900100043 TEMP 1378900100044 K 1378900100045 90. 1378900100046 ENDCOMMON 3 0 1378900100047 ENDSUBENT 46 0 1378900199999 SUBENT 13789002 20020923 00001378900200001 BIB 2 3 1378900200002 REACTION (1-H-1(N,TOT),,SIG,,MXW) 1378900200003 FLAG (1.) Parahydrogen target. 1378900200004 (2.) Orthohydrogen target. 1378900200005 ENDBIB 3 0 1378900200006 NOCOMMON 0 0 1378900200007 DATA 4 4 1378900200008 KT-K DATA DATA-ERR FLAG 1378900200009 K B B NO-DIM 1378900200010 130. 19. 4. 1. 1378900200011 130. 39. 5. 2. 1378900200012 300. 22. 4. 1. 1378900200013 300. 22. 4. 2. 1378900200014 ENDDATA 6 0 1378900200015 ENDSUBENT 14 0 1378900299999 ENDENTRY 2 0 1378999999999