48 Ti(n, xnyp  ) reaction cross sections using spallation neutrons for E n = 1 to 20 MeV Excitation functions have been measured for the interaction of fast neutrons (up to a neutron energy of 250 MeV) on 48 Ti. The Los Alamos Laboratory spallation neutron source, at the LANSCE/WNR facility, provided a “white” neutron beam. The prompt reaction  rays were measured with the large-scale Compton-suppressed Ge spectrometer GEANIE. Excitation functions were converted to partial gamma-ray cross sections taking into account dead-time correction, target thickness, and the detector efficiency. Partial gamma-ray cross sections for transitions in 47,48 Ti and 48 Sc are presented. D. Dashdorj 1, P.E. Garrett 2, J.A. Becker 2, L.A. Bernstein 2, J.R. Cooper 2, M. Devlin 3, N. Fotiadis 3, G.E. Mitchell 1, R.O. Nelson 3, W. Younes 2 1 North Carolina State University and Triangle Universities nuclear Laboratory, 2 Lawrence Livermore National Laboratory, 3 Los Alamos National Laboratory Partial gamma-ray reaction cross sections for 48 Ti(n,n ’  ) 48 Ti transitions Partial gamma-ray reaction cross sections for 48 Ti(n,n ’  ) 48 Ti transitions Captions captions captions captions Analysis During data playback, events were separated into in-beam and out-of-beam matrices 2D matrices E  vs. TOF and  coincidences created The energy calibration was performed using the energies of well-known lines in 48 Ti and other isotopes in in-beam data The excitation functions were obtained by applying TOF gates 15 ns wide on the  -ray events corresponding to the interval E n = 1 to 20 MeV For each energy bin, a 1D  - ray pulse-height spectrum was generated and fitted with the computer code XGAM, and peak areas converted to cross sections. Captions captions captions captions Motivation To measure partial gamma-ray cross sections for 48 Ti + n up to a neutron energy of 250 MeV Provide data in mass and energy region where more data needed Compare results with model calculations (GNASH, STAPRE, …)  provide data  help improve predictive capabilities Part of broader program to study reaction dynamics (e.g. 208 Pb, 196 Pt, 92 Mo, 27 Al, 16 O, …) This work was supported in part by the U. S. Department of Energy Grants No. DE-FG03-03NA00076 and No. DE-FG02-97-ER This work was performed under the auspices of the U. S. Department of Energy by University of California, Lawrence Livermore National Laboratory and Los Alamos National Laboratory under contract Nos. W-7405-ENG-48 and W-7405-ENG-36. Conclusion Extracted partial gamma-ray cross sections n + 48 Ti up to E n = 20 MeV Outline Extend the analysis up to E n = 250 MeV Comparison with the model calculation Examine distribution of spins in pre- equilibrium regime Partial gamma-ray reaction cross sections for 48 Ti(n,p  ) 48 Sc transitions (no corrections for unobserved transitions from theory) Partial gamma-ray reaction cross sections for 48 Ti(n,p  ) 48 Sc transitions (no corrections for unobserved transitions from theory) Partial gamma-ray reaction cross sections for 48 Ti(n,2n  ) 47 Ti transitions (no corrections for unobserved transitions from theory) Partial gamma-ray reaction cross sections for 48 Ti(n,2n  ) 47 Ti transitions (no corrections for unobserved transitions from theory) Measurement Data were collected for about 6 days A gram sample with 99.81% enriched 48 Ti Total of about 4.6  10 8 single- and higher-fold events were recorded The incident neutron energy was determined by the TOF technique The incident neutron flux was obtained from 235/238 U fission chambers An example showing a portion of a fitted spectrum