W. J. Braithwaite

Observation of isospin mixing in 12C near 19.5 MeV excitation

Abstract A strongly isospin-mixed doublet has been found in 12C near 19.5 MeV excitation energy in a comparison of π− and π+ inelastic scattering at 162 MeV. The π+ and π− comparison technique may be universally employable in self-conjugate nuclei to extract isospin-mixing matrix elements.

Studies of the pion double-charge exchange reaction 18O(π+, π−)18Ne☆

Abstract Results of the first measurement if the excitation function of the cross section dσ/dΩ for the pion double charge exchange reaction across the (3,3) π-nucleon resonance are reported. Data from the reaction 18 O(π + , π − ) 18 Ne to the double isobaric analog state at an angle of 5° are presented which show strong structure as a function of pion energy, in contrast to the previous limited data. The measurements were made with the EPICS facility at LAMPF which was modified to allow for data-taking at small angles.

Measurement of isospin mixing between the 1+ doublet in 12C using pion inelastic scattering ☆

Abstract Pion inelastic scattering has been used to extract the off-diagonal charge dependent matrix element, H01, between the Jπ = 1+ doublet of states at 12.71 (T = 0) and 15.11 (T = 1) MeV in 12 C . The reported measurements yield a value, H01 = 148 ±29 keV, in good agreement with recent electromagnetic measurements.

A stable light pulser for gain stabilizing photomultiplier tubes

Abstract We describe a light pulser consisting of an 241 Am source deposited on a CsI crystal, and a method for distinguishing these light pulses from those in a NaI scintillator.

Electric field induced structure in X-ray yields from highly ionized oxygen atoms☆

Abstract Structured yield in delayed X-ray emission from hydrogenic oxygen is reported. Varying the electric potential between the exciter foil and a downstream accelerating grid results in a fluctuating behaviour in the yield of delayed X-ray emission.

Measuring isospin mixing in nuclei using π± inelastic scattering

A new strongly isospin‐mixed doublet has been found in 12C near 19.5 MeV. in a comparison of π− and π+ inelastic scattering at 180 MeV, The present techniques may be universally employable, at least in self‐conjugate nuclei, in extracting isospin‐mixing matrix elements.

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.

L X-ray spectra of chlorine in chlorine-neon collisions (and sulphur in argon-H2S collisions)

Chlorine beam L X-rays were detected using a curved crystal spectrometer. Special attention is given to the observed 2p5 to 2p43s multiplet transitions. The L X-ray line intensities for these multiplets in chlorine do not support statistical population of the initial states, in contrast to previously reported chlorine data.