B. A. Moftah

Neutron-induced peaks in Ge detectors from evaporation neutrons

Abstract We have studied the peak shapes at 596 and 691 keV resulting from fast neutron interactions inside germanium detectors. We have used neutrons from a 252 Cf source, as well as from the 28 Si(μ − , nv), and 209 Bi(π − , xn) reactions to compare the peaks and to check for a dependence of peak shape on the incoming neutron energy. In our investigation, no difference between these three measurements has been observed. In a comparison of these peak shapes with other studies, we found similar results to ours except for those measurements using monoenergetic neutrons in which a significant variation with neutron energy has been observed.

Muon capture in Si-28 and g(p)/g(a)

Abstract Negative muon capture in 28Si was used to determine the angular correlation between the neutrino and the 1229 keV γ-ray from the de-excitation of the 2201 keV 1+ level in 28Al. To suppress backgrounds in the HPGe detectors, a coincidence was required with the 942 keV γ-ray in the de-excitation cascade detected in a NaI array. The extracted angular correlation coefficient α is 0.360 ± 0.059, consistent with previous measurements. Using a recent shell model calculation employing a full 1s-od model space and the USD empirical interaction, this value of α implies a value for the induced pseudoscalar coupling of g p g a = 0.0 ± 3.2 , substantially smaller than the prediction of PCAC and pion-pole dominance.

Measurement of hyperfine transition rates in muonic 19F, 23Na, 31P, and natCl

Abstract From the time dependence of the ( μ − , nν ) reaction we have determined the hyperfine transition rates for the muonic atoms of 19 F, 23 Na, and nat Cl, obtaining Λ h =4.9±1.2 μ s −1 , 8.4±1.9 μ s −1 , and 6.5±0.9 μ s −1 , respectively. Further, from the branching ratios of the ( μ −1 , ν ) reaction on muonic 31 P we have inferred a hyperfine transition rate that is much faster than the muon disappearance rate, Λ h ⪢ Λ D . These results are in reasonable agreement with the rates calculated for Auger emission, and qualitatively confirm the correction to the muonic atoms hyperfine splitting due to the distribution of magnetism in the nucleus. The 31 P result, however, disagrees with an earlier suggestion of the inhibition of Auger emission.

{gamma} rays from muon capture in {sup 27}Al and natural Si

Muon capture

Muon capture on 35 Cl

\ensuremath{\gamma}

Dependence on neutron energy of neutron-induced peaks in Ge detectors

rays have been observed for the first time in

Measurement of the hyperfine transition rates in μ−f, Na, Al, P, and Cl, and the hyperfine dependence of μ− capture

^{27}\mathrm{Al}

Measurement of partial muon capture rates in 1 s − 0 d shell nuclei

, and a significant improvement has been made in the identification of \ensuremath{\gamma}-rays from muon capture in natural Si. The (

Observables in muon capture on Na 23 and the effective weak couplings g ̃ a and g ̃ p

{\ensuremath{\mu}}^{\ensuremath{-}},\ensuremath{\nu}\ensuremath{\gamma}

gamma rays from muon capture in Al-27 and natural Si

) reaction was clearly observed in both nuclei and, for