ENTRY 14323 20120522 13831432300000001 SUBENT 14323001 20120522 13831432300100001 BIB 12 69 1432300100002 TITLE Parity nonconservation in neutron resonances in 232Th 1432300100003 AUTHOR (S.L.Stephenson,J.D.Bowman,B.E.Crawford,P.P.J.Delheij, 1432300100004 C.M.Frankle,M.Iinuma,J.N.Knudson,L.Y.Lowie,A.Masaike, 1432300100005 Y.Matsuda,G.E.Mitchell,S.I.Penttila,H.Postma, 1432300100006 N.R.Roberson, S.J.Seestrom,E.I.Sharapov,Y.-F.Yen, 1432300100007 V.W.Yuan) 1432300100008 REFERENCE (J,PR/C,58,(2),1236,1998) 1432300100009 #doi:10.1103/PhysRevC.58.1236 1432300100010 REL-REF (M,14276001,B.E.Crawford+,J,PR/C,58,(2),1225,1998) 1432300100011 (R,10973001,D.K.Olsen+,J,NSE,82,289,1982) 1432300100012 (R,,Mughabghab+,B,NEUT.CS 1B,1,(B),1988) 1432300100013 INSTITUTE (1USANCS,1USATNL,1USALAS,1USADKE,1CANTMF,2JPNKTO, 1432300100014 2NEDDEL,4ZZZDUB) 1432300100015 FACILITY (LINAC,1USALAS) 1432300100016 INC-SOURCE (SPALL) The stored proton beam is directed towards 1432300100017 tungsten spallation target and approximately 17 fast 1432300100018 neutrons in the MeV energy range are produced for 1432300100019 each incident proton. 1432300100020 PART-DET (N) 1432300100021 DETECTOR (SCIN) The neutron detector system consists of 55 1432300100022 liquid scintillator cells optically coupled to 1432300100023 photomultipliers (PMT's). The segmented nature of the 1432300100024 detector allows very high instantaneous counting 1432300100025 rates, while the thickness of the scintillator is 1432300100026 such that most of the neutrons are thermalized and 1432300100027 captured, giving the detector a very high and almost 1432300100028 energy independent efficiency. 1432300100029 METHOD (TRN,TOF,TTM) The resonances in 232TH were studied by 1432300100030 transmitting neutrons through a thick sample. The 1432300100031 initial energy calibration was performed using 1432300100032 previous resonance data of Olsen and Mughabghab. For 1432300100033 the 100-ns data the time-of-flight length was 1432300100034 L=56.804 m and the channel offset was C0=7.42 1432300100035 channels, while the corresponding values for the 1432300100036 200-ns data were L=56.795 m and C0=4.18 channels. The 1432300100037 statistical error in these values is very small, but 1432300100038 the total error is not known since the errors in the 1432300100039 resonance energies used to determine L and C0 were 1432300100040 not given in Refs. Using the values of L and C0 given 1432300100041 above, the resonance energies were converted back to 1432300100042 time-of-flight channels and related to the Olsen 1432300100043 resonance energies by E=5.23x10-9[L2/d2(C+Co)2], 1432300100044 where d is the dwell time. 1432300100045 ANALYSIS (SHAPE) In the analysis to determine the resonance 1432300100046 parameters, 30 runs were summed for the 100-ns data 1432300100047 as well as the 200-ns data as a compromise between 1432300100048 better statistics and the maintenance of uniform 1432300100049 experimental conditions. Due to the thickness of the 1432300100050 thorium target, many of the s-wave resonances 1432300100051 absorbed all neutrons. After the standard background 1432300100052 correction there were still some counts under these 1432300100053 resonances. The remaining counts were fit to a 1432300100054 polynomial function of 1/TOF. These background 1432300100055 parameters were held fixed for the rest of the 1432300100056 fitting process. First a large energy region was fit 1432300100057 with known s-wave resonance parameters, allowing the 1432300100058 magnitude and energy dependence of the flux to vary. 1432300100059 The energy dependence was then fixed. Then a smaller 1432300100060 energy region was fit, allowing E(s), gGamma-n(s), 1432300100061 and Gamma-gamma(s) to vary. This process was then 1432300100062 repeated after adding a higher energy region with 1432300100063 some additional s-wave resonances. These new 1432300100064 resonances were then fit, with the resonance 1432300100065 parameters for the first s-wave resonances held 1432300100066 fixed. This process was iterated until the s-wave 1432300100067 parameters were stable. Then the p-wave resonances 1432300100068 were fit while allowing only the flux and the p-wave 1432300100069 resonance parameters to vary. 1432300100070 HISTORY (20120522C) BP 1432300100071 ENDBIB 69 0 1432300100072 NOCOMMON 0 0 1432300100073 ENDSUBENT 72 0 1432300199999 SUBENT 14323002 20120522 13831432300200001 BIB 5 21 1432300200002 REACTION 1(90-TH-232(N,0),,EN) 1432300200003 2(90-TH-232(N,0),,L) 1432300200004 3(90-TH-232(N,0),,J) 1432300200005 4(90-TH-232(N,EL),,WID,,G) 1432300200006 5(90-TH-232(N,G),,WID) 1432300200007 STATUS (TABLE) Table I, page 1240. 1432300200008 ANALYSIS L values were deduced using the Bayesian analysis for 1432300200009 p-wave probabilities. The Bayesian analysis uses the 1432300200010 measured widths, strength functions, and level 1432300200011 densities, and relies mainly on the large difference 1432300200012 in s- and p-wave penetrabilities. 1432300200013 ERR-ANALYS (DATA-ERR) No details are given, these resonances and 1432300200014 their errors were previously known. 1432300200015 (ERR-T) The errors include the statistical uncertainty 1432300200016 and the estimated systematic uncertainties: 1432300200017 (ERR-1) 2% uncertainty due to fitting process. 1432300200018 (ERR-2) 2% uncertainty included for the p-wave due to 1432300200019 small fluctuations in the flux. 1432300200020 FLAG (1.) J=0.5 is assigned to p-wave resonances with 1432300200021 statistically significant PNC(Parity Non Conservation) 1432300200022 asymmetries. 1432300200023 ENDBIB 21 0 1432300200024 COMMON 2 3 1432300200025 ERR-1 ERR-2 1432300200026 PER-CENT PER-CENT 1432300200027 2. 2. 1432300200028 ENDCOMMON 3 0 1432300200029 DATA 9 39 1432300200030 DATA 1DATA-ERR 1DATA 2DATA 3DATA 4ERR-T 41432300200031 DATA 5ERR-T 5FLAG 1432300200032 EV EV NO-DIM NO-DIM EV EV 1432300200033 EV EV NO-DIM 1432300200034 8.36032 0.0012 1. 0.5 2.67E-7 4.0E-91432300200035 1. 1432300200036 13.1377 0.0018 1. 1.93E-7 4.0E-91432300200037 1432300200038 21.819 0.003 0. 0.5 2.18E-3 4.4E-51432300200039 2.498E-2 5.0E-4 1. 1432300200040 23.454 0.003 0. 0.5 4.1E-3 8.2E-51432300200041 2.416E-2 4.8E-4 1. 1432300200042 36.982 0.004 1.0 8.82E-7 1.8E-81432300200043 1432300200044 38.232 0.004 1.0 0.5 4.81E-7 1.0E-81432300200045 1. 1432300200046 41.066 0.005 1.0 5.1E-7 1.0E-81432300200047 1432300200048 47.068 0.005 1.0 0.5 1.74E-6 3.5E-81432300200049 1. 1432300200050 49.941 0.006 1.0 4.29E-7 1.0E-81432300200051 1432300200052 58.786 0.009 1. 9.2E-6 1.8E-71432300200053 1432300200054 59.523 0.009 0.0 0.5 3.88E-3 8.3E-51432300200055 2.393E-2 4.9E-4 1. 1432300200056 64.575 0.0010 1.0 0.5 7.94E-7 3.7E-81432300200057 1. 1432300200058 69.228 0.0015 0.0 0.5 4.452E-2 9.1E-41432300200059 2.065E-2 5.6E-4 1. 1432300200060 90.139 0.01 1.0 5.59E-6 1.3E-71432300200061 1432300200062 98.057 0.013 1.0 0.5 4.29E-6 9.8E-81432300200063 1. 1432300200064 103.63 0.01 1.0 6.5E-6 1.3E-71432300200065 1432300200066 113.00 0.01 0.0 0.5 1.307E-2 2.7E-41432300200067 2.398E-2 5.2E-4 1. 1432300200068 120.83 0.02 0.0 0.5 2.267E-2 4.7E-41432300200069 2.354E-2 5.1E-4 1. 1432300200070 128.17 0.02 1.0 0.5 8.01E-5 4.4E-61432300200071 1. 1432300200072 129.16 0.02 0.0 0.5 3.59E-3 7.9E-41432300200073 2.754E-2 1.10E-3 1. 1432300200074 145.83 0.02 1.0 8.8E-5 3.0E-61432300200075 1432300200076 148.06 0.02 1.0 6.3E-6 1.0E-71432300200077 1432300200078 154.29 0.02 0.0 0.5 1.93E-4 1.5E-51432300200079 2.251E-2 4.9E-4 1. 1432300200080 167.11 0.003 1.0 0.5 2.35E-5 6.0E-71432300200081 1. 1432300200082 170.30 0.04 0.0 0.5 6.223E-2 1.35E-31432300200083 2.214E-2 1.18E-3 1. 1432300200084 178.86 0.03 1.0 2.46E-5 7.0E-71432300200085 1432300200086 192.60 0.03 0.0 0.5 1.636E-2 3.6E-41432300200087 2.382E-2 4.8E-4 1. 1432300200088 196.20 0.03 1.0 0.5 7.0E-5 2.0E-61432300200089 1. 1432300200090 199.25 0.03 0.0 0.5 9.58E-3 1.9E-41432300200091 2.054E-2 4.3E-4 1. 1432300200092 202.58 0.03 1.0 0.5 4.22E-5 2.0E-61432300200093 1. 1432300200094 210.91 0.03 1.0 1.81E-5 4.0E-71432300200095 1432300200096 221.11 0.04 0.0 0.5 2.925E-2 6.0E-41432300200097 2.316E-2 4.7E-4 1. 1432300200098 231.95 0.04 1.0 0.5 1.02E-5 5.0E-71432300200099 1. 1432300200100 234.07 0.04 1.0 1.161E-5 4.0E-71432300200101 1432300200102 242.25 0.04 1.0 4.34E-5 9.0E-71432300200103 1432300200104 251.47 0.05 0.0 0.5 3.105E-2 6.5E-41432300200105 2.609E-2 8.1E-4 1. 1432300200106 263.04 0.05 0.0 0.5 2.116E-2 5.0E-41432300200107 2.498E-2 7.1E-4 1. 1432300200108 276.45 0.03 1.0 8.6E-6 2.0E-71432300200109 1432300200110 285.68 0.06 0.0 0.5 3.056E-2 7.6E-41432300200111 2.586E-2 1.04E-3 1. 1432300200112 ENDDATA 82 0 1432300200113 ENDSUBENT 112 0 1432300299999 ENDENTRY 2 0 1432399999999