Joseph Edward Bolger

A digital technique for neutron-gamma pulse shape discrimination

Abstract A technique employing integrating analog-to-digital converters to do pulse shape discrimination between neutron and gamma initiated scintillations in liquid scintillators is described. The technique involves a direct comparison of the fast and slow components of the light output from the scintillator.

Observation of plasmon excitations in X-ray production following heavy ion bombardment

Abstract Four equidistant peaks are observed below the Kα 1,2 line in the X-ray spectra of Na, Al, Si, SiO 2 , Ca, Sc and Ti, produced by oxygen bombardment. With much weaker intensity, these lines are also seen in proton excitation. The lines are interpreted to be due to the excitation of one or more volume plasmons in the target material by the Kα 1,2 X-ray decay.

Molecular structure effects of aluminum Kβ x-ray spectra produced in proton and alpha particle excitation☆

Abstract Targets of Al and Al2O3 were bombarded by 0.8 MeV protons and 3.2 MeV alpha particles and the subsequent X-ray yield measured. The Kα X-ray spectra of Al and Al2O3 show fairly good agreement in both the proton and alpha-induced spectra; however, the structure in the Kβ X-ray spectra deviate from one another in both cases. These results are interpreted as effects due to the chemical bonding of the oxygen atoms to aluminum.

K X-ray satellite transitions in cobalt

Bombardment of cobalt with 42 MeV oxygen ions is seen to produce multiple inner shell electron excitation.Kα andKβ X-rays are measured and compared to Hartree-Fock-Slater calculated energies. This study of cobalt is the highestZ element where the satellite X-ray spectrum has been studied with good resolution.

Energy dependence of π+ induced two- and four-nucleon removal☆

Abstract De-excitation γ-rays have been detected from nuclear states following positive pion induced two-nucleon removal from 12 C and four-nucleon removal from 16 O. Excitation functions for population of discrete states were obtained for positive pions of 75, 125, 150, 200, 225, 250 and 290 MeV. The pion-nucleon (3, 3) resonance is not reflected in the cross sections for either reaction. Implications of the observed energy dependence are discussed.

High resolution beam gas Auger electron spectra for oxygen ions excited by collisions with He, Ne, and Ar

Abstract Initial high resolution measurements of projectile electron emission spectra for beam gas collisions are reported. The Auger electron decay of beams of O + , O 2+ , and O 3+ at 3, 8, and 18 MeV, respectively, excited by single collisions with He, Ne, and Ar was measured at a lab emission angle of 23.7° with a 36 cm double focussing electrostatic analyzer. Although prompt transitions are found to predominate the spectra, several weak lines are attributed to transitions from metastable states. Spectral features are seen to vary greatly as a function of exciter gas and as a function of projectile charge state and energy.

Neon K X-ray spectra excited by O4+ and Cl4+ bombardment

Neon K X-ray spectra resulting from O4+ and Cl4+ bombardment are observed to have dissimilar K alpha satellite intensities. These results are in contrast to similar measurements made using C6+, N6+ and O6+ bombardment.