Resonance Parameters and Uncertainties Derived from Epithermal Neutron Capture and Transmission Measurements of Natural Molybdenum
Abstract The electron linear accelerator facility at the Rensselaer Polytechnic Institute was used to explore neutron interactions with molybdenum in the energy region from 10 eV to 2 keV. Neutron capture and transmission measurements were performed by the time-of-flight technique. Resonance parameters were extracted from the data using the multilevel R-matrix Bayesian code SAMMY. A table of resonance parameters and their uncertainties is presented. Two transmission measurements were performed at a flight path of 25 m with a 6Li glass scintillation detector. The neutron capture measurements were performed at a flight path of 25 m with a 16-segment sodium iodide multiplicity detector. Nine different thicknesses of elemental molybdenum metal samples ranging from 0.051 mm (0.002 in.) to 6.35 mm (0.250 in.) were measured in either capture or transmission. Reductions in resonance integrals were observed when compared to ENDF/B-VII.0 for six of the seven stable isotopes. The largest reductions were 9% in 97Mo and 11% in 100Mo. The one measured increase in resonance integral relative to ENDF/B-VII.0 occurred in 95Mo, and it was significant (10%). The measured distribution of neutron widths for 95Mo and 97Mo are a better match to a Porter-Thomas distribution than those of ENDF/B-VII.0. Neutron strength functions for 95Mo and 97Mo were measured and compared to ENDF/B-VII.0. The strength of 95Mo and 97Mo are within uncertainties of each other. The measured radiation width distribution for 95Mo and 97Mo are compared to those of ENDF/B-VII.0 and to χ2 distributions. Significant aspects of this analysis are the assignment of radiation widths, the determination of the transmission resolution function, and the propagation of experimental uncertainties into resonance parameter uncertainties.
Isotopic molybdenum total neutron cross section in the unresolved resonance region
R. Bahran,1,* D. Barry,2 R. Block,2 G. Leinweber,2 M. Rapp,2 A. Daskalakis,1 E. Blain,1 D. Williams,1,† B. McDermott,1 L. Leal,3 and Y. Danon1 1Gaerttner LINAC Center, Rensselaer Polytechnic Institute, Troy, New York 12180, USA 2Bechtel Marine Propulsion Corp., Knolls Atomic Power Laboratory, P.O. Box 1072, Schenectady, New York 12301, USA 3Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6171, USA (Received 20 November 2014; published 4 August 2015)
Coherent pulsed injection seeding of two gain-switched semiconductor lasers
High-power, narrow-spectrum, short pulses at a wavelength near 830 nm are needed for optical logic applications. The authors report the generation of two coherent trains of pulses by pulsed injection seeding of two gain-switched semiconductor lasers with one mode-locked master oscillator. The available power was doubled and both lasers emit in nearly identical spectral lines. Short pulses (30-50 ps) are generated at a repetition rate of 1.9 GHz. The spectrum is reduced to a single mode cluster and shows a 1.7 AA wide chirp suitable for pulse compression. The peak power is 0.1 W for each pulse train. The capability of this technique for coherent power combining is demonstrated.<<ETX>>