ENTRY 14566 20190712 14561456600000001 SUBENT 14566001 20190712 14561456600100001 BIB 12 70 1456600100002 TITLE Measurement of the scattering cross section of slow 1456600100003 neutrons on liquid parahydrogen from neutron 1456600100004 transmission 1456600100005 AUTHOR (K.B.Grammer,R.Alarcon,L.Barron-Palos,D.Blyth, 1456600100006 J.D.Bowman, J.Calarco,C.Crawford,K.Craycraft,D.Evans, 1456600100007 N.Fomin,J.Fry,M.Gericke,R.C.Gillis,G.L.Greene, 1456600100008 J.Hamblen,C.Hayes,S.Kucuker,R.Mahurin, 1456600100009 M.Maldonado-Velazquez,E.Martin,M.McCrea, 1456600100010 P.E.Mueller, M.Musgrave,H.Nann,S.I.Penttila,W.M.Snow, 1456600100011 Z.Tang, W.S.Wilburn) 1456600100012 REFERENCE (J,PR/B,91,180301,2015) 1456600100013 #doi:10.1103/PhysRevB.91.180301 1456600100014 INSTITUTE (1USATEN,1USAASU,3MEXIFM,1USAORL,1USAUNH,1USAKTY, 1456600100015 1USAVIR,1USAINU,1CANMNA,1USAMTS,1USALAS) 1456600100016 (1USAUSA) University of Tennessee-Chattanooga, 1456600100017 Chattanooga, Tennessee 37403, USA 1456600100018 FACILITY (LINAC,1USAORL) The Spallation Neutron Source at Oak 1456600100019 Ridge National Laboratory. 1456600100020 INC-SOURCE (SPALL) Proton on liquid Hg 1456600100021 SAMPLE A 16-liter liquid hydrogen target at a temperature of 1456600100022 15.6+-0.6 K. The molecular hydrogen has two spin 1456600100023 states, labeled orthohydrogen (J=odd) and parahydrogen 1456600100024 (J=even). The lowest orthohydrogen state (J=1) lies 1456600100025 14.5 meV above the lowest parahydrogen state (J=0). 1456600100026 DETECTOR (CSICR,IOCH) NPDGamma experiment 48 cesium iodide 1456600100027 crystals, 3He ion plate chamber. 1456600100028 METHOD (TRN) Neutrons pass through the normalization 1456600100029 monitor, a multiwire proportional counter with a gas 1456600100030 mixture of 3He (15.1 Torr) and N2 (750 Torr) located 1456600100031 15.24+-0.12 m from the moderator, and are incident on 1456600100032 the 16-liter liquid hydrogen target centered 17.6 m 1456600100033 from the moderator. Roughly 60% of the neutron beam 1456600100034 is captured on the hydrogen in the target with the 1456600100035 2.2 MeV capture gammas relevant to the NPDGamma 1456600100036 experiment detected by 48 cesium iodide crystals. The 1456600100037 effective length of liquid hydrogen covered by the 1456600100038 neutron beam cross-sectional area including beam 1456600100039 divergence is 30.065+-0.005 cm when cold. The 1456600100040 transmitted neutrons exit the down stream end of the 1456600100041 target vessel through a 2.5-cm-diameter aperture in 1456600100042 the 6Li-rich neutron absorber surrounding the target. 1456600100043 The transmitted neutron intensity is measured in a 1456600100044 3He plate ion chamber located 3.44+-0.02 m from the 1456600100045 normalization monitor. Two different measurements 1456600100046 were required in order to measure the empty target 1456600100047 and full target transmissions. The full target 1456600100048 measurement was performed over eight hours with the 1456600100049 target vessel at 15.6 K after the target had been 1456600100050 in steady-state operation for four weeks, which 1456600100051 corresponds to 30 conversion time constants. The 1456600100052 empty target measurement was performed two weeks 1456600100053 later with the target vessel at 16.3 K in order to 1456600100054 cancel the temperature dependence of scattering from 1456600100055 the aluminum target vessel. 1456600100056 ERR-ANALYS (DATA-ERR) From equation 2: sigma total = sigma 1456600100057 absorption + f sigma-para + (1-f) sigma-ortho. The 1456600100058 upper error bar is carried over from the total cross 1456600100059 section uncertainties. In order to determine the 1456600100060 lower error bar, an upper limit on the orthohydrogen 1456600100061 concentration was determined by assuming that 1456600100062 sigma-para=0 at the lowest measured value 1456600100063 (corresponding to 0.8meV), and then the corresponding 1456600100064 f along with the ENDF/B-VII orthohydrogen cross 1456600100065 section was used to determine the lower value for all 1456600100066 other measured points. This produces a measurement 1456600100067 band for sigma-para, rather than sigma-para since the 1456600100068 apparatus had no method to measure the orthohydrogen 1456600100069 fraction. 1456600100070 STATUS (APRVD) Approved by K.B. Grammer on July 15, 2019. 1456600100071 HISTORY (20190712C) BP 1456600100072 ENDBIB 70 0 1456600100073 NOCOMMON 0 0 1456600100074 ENDSUBENT 73 0 1456600199999 SUBENT 14566002 20190712 14561456600200001 BIB 3 5 1456600200002 REACTION (1-H-1(N,TOT),,SIG,,TMP) 1456600200003 COMMENT Compiler's comment: Original article units are in 1456600200004 b/atom. 1456600200005 STATUS (TABLE) Authors' data. They are shown in Fig. 6, page 1456600200006 180301-4. 1456600200007 ENDBIB 5 0 1456600200008 COMMON 2 3 1456600200009 TEMP TEMP-ERR 1456600200010 K K 1456600200011 15.6 0.6 1456600200012 ENDCOMMON 3 0 1456600200013 DATA 3 130 1456600200014 EN DATA DATA-ERR 1456600200015 EV B B 1456600200016 0.0161166 3.73153 0.13904 1456600200017 0.0149702 2.73734 0.11774 1456600200018 0.0139419 2.10658 0.10014 1456600200019 0.0130161 1.79662 0.08344 1456600200020 0.0109541 1.59075 0.04897 1456600200021 0.0103056 1.58692 0.04477 1456600200022 0.00971301 1.59395 0.03982 1456600200023 0.00917012 1.60966 0.03483 1456600200024 0.00867145 1.62836 0.03068 1456600200025 0.00821242 1.64876 0.02923 1456600200026 0.00778891 1.67039 0.02803 1456600200027 0.00739733 1.69235 0.02672 1456600200028 0.00703455 1.71438 0.02606 1456600200029 0.00669782 1.73726 0.02583 1456600200030 0.0063847 1.76026 0.02651 1456600200031 0.00609304 1.78362 0.02566 1456600200032 0.00582091 1.80708 0.02294 1456600200033 0.00556662 1.8303 0.02121 1456600200034 0.00532863 1.85364 0.02241 1456600200035 0.00510559 1.87789 0.0303 1456600200036 0.00489623 1.89723 0.03082 1456600200037 0.00469952 1.92298 0.02862 1456600200038 0.00451443 1.94602 0.0228 1456600200039 0.00434006 1.96793 0.02158 1456600200040 0.00417561 1.98923 0.02092 1456600200041 0.00402032 2.00944 0.02091 1456600200042 0.00387354 2.02919 0.02148 1456600200043 0.00373466 2.04732 0.02512 1456600200044 0.00360311 2.06263 0.02233 1456600200045 0.00347839 2.07808 0.02096 1456600200046 0.00336004 2.09088 0.021 1456600200047 0.00324762 2.10128 0.02137 1456600200048 0.00314074 2.10936 0.02167 1456600200049 0.00303907 2.11483 0.02187 1456600200050 0.00294225 2.11759 0.02201 1456600200051 0.00284999 2.11726 0.02215 1456600200052 0.002762 2.11339 0.02229 1456600200053 0.00267802 2.10584 0.02245 1456600200054 0.00259782 2.0944 0.02261 1456600200055 0.00252116 2.07858 0.02275 1456600200056 0.00244785 2.05912 0.02289 1456600200057 0.00237769 2.03554 0.02303 1456600200058 0.0023105 2.00865 0.02313 1456600200059 0.00224612 1.9791 0.02325 1456600200060 0.00208704 1.89381 0.02347 1456600200061 0.00203171 1.86226 0.0235 1456600200062 0.00197855 1.83255 0.02358 1456600200063 0.00192745 1.80531 0.02366 1456600200064 0.00187831 1.78105 0.02375 1456600200065 0.00183103 1.75989 0.02382 1456600200066 0.00178551 1.74166 0.0239 1456600200067 0.00174166 1.72662 0.02398 1456600200068 0.00169941 1.71426 0.02407 1456600200069 0.00165868 1.70457 0.02414 1456600200070 0.0016194 1.69739 0.0242 1456600200071 0.00158149 1.69253 0.02424 1456600200072 0.0015449 1.68954 0.02428 1456600200073 0.00150956 1.68826 0.02429 1456600200074 0.00147543 1.6884 0.02432 1456600200075 0.00144244 1.68987 0.02437 1456600200076 0.00141054 1.69242 0.02443 1456600200077 0.00137969 1.69594 0.02447 1456600200078 0.00134984 1.70056 0.02445 1456600200079 0.00132095 1.70612 0.02446 1456600200080 0.00129298 1.71332 0.02444 1456600200081 0.00126589 1.72159 0.02446 1456600200082 0.00123963 1.73005 0.0245 1456600200083 0.00121419 1.73889 0.02453 1456600200084 0.00118952 1.74784 0.02457 1456600200085 0.0011656 1.75685 0.02461 1456600200086 0.00114239 1.76625 0.02464 1456600200087 0.00111987 1.77603 0.02468 1456600200088 0.001098 1.78658 0.02471 1456600200089 0.00107678 1.79792 0.02475 1456600200090 0.00105616 1.80937 0.02478 1456600200091 0.00103612 1.82127 0.0248 1456600200092 0.00101666 1.83308 0.02483 1456600200093 0.000997732 1.84492 0.02486 1456600200094 0.000979332 1.85687 0.02489 1456600200095 0.000961435 1.86862 0.02493 1456600200096 0.000944025 1.8807 0.02497 1456600200097 0.000927082 1.89252 0.02501 1456600200098 0.000910592 1.90545 0.02506 1456600200099 0.000894539 1.91828 0.0251 1456600200100 0.000853747 1.95987 0.02525 1456600200101 0.000839167 1.97694 0.02532 1456600200102 0.000824957 1.99633 0.0254 1456600200103 0.0008111 2.01461 0.02548 1456600200104 0.000797606 2.03139 0.02559 1456600200105 0.00078443 2.04715 0.02572 1456600200106 0.000771577 2.06092 0.02584 1456600200107 0.000759038 2.07498 0.02598 1456600200108 0.000746817 2.08821 0.02612 1456600200109 0.000734874 2.10183 0.02627 1456600200110 0.000723216 2.11702 0.02643 1456600200111 0.000711846 2.13237 0.02662 1456600200112 0.000700729 2.15126 0.02683 1456600200113 0.000689871 2.17009 0.02707 1456600200114 0.000679275 2.18883 0.02732 1456600200115 0.00066891 2.20866 0.0276 1456600200116 0.00065878 2.22641 0.02792 1456600200117 0.000648878 2.24398 0.02825 1456600200118 0.000639209 2.26125 0.02863 1456600200119 0.000629744 2.27793 0.02905 1456600200120 0.000620487 2.2975 0.0295 1456600200121 0.000611444 2.31743 0.02999 1456600200122 0.000602587 2.33672 0.03055 1456600200123 0.00059392 2.35654 0.03112 1456600200124 0.000585439 2.37177 0.03175 1456600200125 0.000577149 2.38652 0.03244 1456600200126 0.000569023 2.39983 0.03316 1456600200127 0.000561068 2.41189 0.0339 1456600200128 0.000553288 2.43153 0.03479 1456600200129 0.00054566 2.44874 0.03572 1456600200130 0.000538188 2.4708 0.03677 1456600200131 0.000530869 2.49556 0.03794 1456600200132 0.000523706 2.51441 0.03915 1456600200133 0.000516679 2.53493 0.0405 1456600200134 0.000509793 2.54744 0.04184 1456600200135 0.000503051 2.55945 0.04327 1456600200136 0.000496435 2.57502 0.04488 1456600200137 0.000489948 2.58752 0.04651 1456600200138 0.000483595 2.60772 0.04844 1456600200139 0.000477357 2.6281 0.05048 1456600200140 0.000461306 2.68044 0.05661 1456600200141 0.000455493 2.67702 0.05836 1456600200142 0.00044979 2.6954 0.06112 1456600200143 0.000444199 2.71764 0.06423 1456600200144 0.000438706 2.74254 0.06774 1456600200145 0.000433313 2.78189 0.07229 1456600200146 ENDDATA 132 0 1456600200147 ENDSUBENT 146 0 1456600299999 ENDENTRY 2 0 1456699999999