ENTRY 14853 20250815 1485300000001 SUBENT 14853001 20250815 20260228 1485300100001 BIB 12 52 1485300100002 TITLE Measurement of the isomeric yield ratio for 88Zr 1485300100003 thermal neutron absorption 1485300100004 AUTHOR (I.Kelly,W.Flanagan,J.Moldenhauer,W.Charlton,J.Lapka, 1485300100005 D.Nolting) 1485300100006 REFERENCE (J,PR/C,111,L021601,2025) 1485300100007 #doi:10.1103/PhysRevC.111.L021601 1485300100008 REL-REF (R,14520003,J.A.Shusterman+,J,NAT,565,328,2019) Thermal1485300100009 neutron cross sections for mathematical model. 1485300100010 INSTITUTE (1USADLS,1USATEX) 1485300100011 FACILITY (REAC,1USATEX) The TRIGA Mark II nuclear research 1485300100012 reactor at the Nuclear Engineering Teaching Lab- 1485300100013 oratory (NETL) at the University of Texas. 1485300100014 INC-SPECT The TRIGA Mark II nuclear research reactor at NETL 1485300100015 thermal neutron flux of ~10**12 n/cm2/s. The flux is 1485300100016 derived by scaling an MCNP spectra which has been 1485300100017 tuned by 47 foils and subsequent unfolding with the 1485300100018 SAND-II package with the amount of 99Mo activity 1485300100019 created during exposure of the natural molybdenum 1485300100020 monitoring wire. The flux at 0.025 eV is (4.38+-0.22) 1485300100021 *10**12 n/cm2/s. 1485300100022 DETECTOR (HPGE) The HPGe system. 1485300100023 SAMPLE A sample of 88Zr was produced at Los Alamos National 1485300100024 Laboratory Isotope Production Facility through proton 1485300100025 irradiation of a yttrium target 89Y(p,2n)88Zr and 1485300100026 was delivered to NETL in 2N HCl solution. As the 1485300100027 sample was over a year past initial separation, the 1485300100028 88Y activity exceeded the 88Zr activity. These 1485300100029 factors motivated a 88Zr/88Y separation. This was 1485300100030 accomplished by immersing the sample within 0.01 M 1485300100031 HDEHP in dodecane. The 88Zr residue was dissolved in 1485300100032 2M nitric acid, transferred dropwise onto Kapton tape, 1485300100033 and evaporated to dryness by heating. Kapton is a 1485300100034 polyimide (C41H22N4O11) film with a silicone adhesive 1485300100035 backing. The dried sample was sealed in two High- 1485300100036 density polyethylene (HDPE) vials for irradiation 1485300100037 along with a natural molybdenum flux monitor wire. A 1485300100038 88Zr sample activity of 5 microCi was chosen to 1485300100039 maximize the number of target atoms without creating an1485300100040 unmanageable dead-time during post-exposure counting. 1485300100041 METHOD (ACTIV) The simultaneous measurement of 89mZr and 1485300100042 89Zr requires a high neutron flux as well as prompt 1485300100043 counting after exposure. Zirconium sample, 1485300100044 accompanied by a 6mg natural molybdenum flux monitor, 1485300100045 was irradiated for 10 min. Upon end of irradiation 1485300100046 the sample was counted in a HPGe with an ORTEC DSPEC 1485300100047 50 MCA. Measurement began 180 s after end of 1485300100048 irradiation, at which point the 588 keV 89mZr 1485300100049 activity was 500 counts/s. Spectra were extracted 1485300100050 from the ORTEC MCA, corrected for deadtime, and 1485300100051 background subtracted. 1485300100052 ERR-ANALYS (DATA-ERR) The MINUIT package fitting uncertainties. 1485300100053 HISTORY (20250815C) BP 1485300100054 ENDBIB 52 0 1485300100055 COMMON 1 3 1485300100056 EN-DUMMY 1485300100057 EV 1485300100058 0.0253 1485300100059 ENDCOMMON 3 0 1485300100060 ENDSUBENT 59 0 1485300199999 SUBENT 14853002 20250815 20260228 1485300200001 BIB 4 15 1485300200002 REACTION (40-ZR-88(N,G)40-ZR-89-M/G,,SIG/RAT,,SPA) 1485300200003 DECAY-DATA (40-ZR-88,83.4D,DG,393.0) 1485300200004 (40-ZR-89-G,78.361HR,DG,909.0,0.9914) 1485300200005 (40-ZR-89-M,4.161MIN,DG,588.0,0.9533, 1485300200006 DG,1507.0) 1485300200007 (39-Y-89-M,15.663SEC) 1485300200008 ANALYSIS The amounts of 89Zr and 89mZr created by the 1485300200009 88Zr(n,gamma) reaction both depend almost directly on 1485300200010 flux, initial sample size, and cross section. By 1485300200011 taking the ratio of the respective signals from these 1485300200012 products, the uncertainty from these variables is 1485300200013 minimized and the IYR better isolated. Chi-squared 1485300200014 minimization was performed with MINUIT. 1485300200015 STATUS (TABLE,,I.Kelly+,J,PR/C,111,L021601,2025) 1485300200016 Page - L021601-3 1485300200017 ENDBIB 15 0 1485300200018 NOCOMMON 0 0 1485300200019 DATA 2 1 1485300200020 DATA DATA-ERR 1485300200021 NO-DIM NO-DIM 1485300200022 0.7489 0.0061 1485300200023 ENDDATA 3 0 1485300200024 ENDSUBENT 23 0 1485300299999 ENDENTRY 2 0 1485399999999