Parity Nonconservation in Neutron Resonances in 133Cs

Spatial parity nonconservation (PNC) has been studied in the compound-nuclear states of 134Cs by measuring the helicity dependence of the neutron total cross section. Transmission measurements on a thick 133Cs target were performed by the time-of-flight method at the Manuel Lujan Neutron Scattering Center with a longitudinally polarized neutron beam in the energy range from 5 to 400 eV. A total of 28 new p-wave resonances were found, their neutron widths determined, and the PNC longitudinal asymmetries of the resonance cross sections measured. The value obtained for the root-mean-square PNC element M=(0.06-0.02+0.25) meV in 133Cs is the smallest among all targets studied. This value corresponds to a weak spreading width Γw=(0.006-0.003+0.154)×10-7 eV

Parity Violation in Neutron Resonances of Palladium

Parity violation in p-wave neutron resonances of the palladium isotopes 104, 105, 106, and 108 has been measured by transmission of a longitudinally polarized neutron beam through a natural palladium target. The measurements were performed at the pulsed spallation neutron source of Los Alamos Neutron Science Center. The rms weak interaction matrix elements and the corresponding spreading widths were determined for 104 Pd, 105 Pd, and 106 P

TeV Gamma Ray Emission from Southern Sky Objects and CANGAROO Project

We report recent results of the CANGAROO Collaboration on very high energy gamma ray emission from pulsars, their nebulae, SNR and AGN in the southern sky. Observations are made in South Australia using the imaging technique of detecting atmospheric Cerenkov light from gamma rays higher than about 1 TeV. The detected gamma rays are most likely produced by the inverse Compton process by electrons which also radiate synchrotron X-rays. Together with information from longer wavelengths, our results can be used to infer the strength of magnetic field in the emission region of gamma rays as well as the energy of the progenitor electrons. A description of the CANGAROO project is also given, as well as details of the new telescope of 7 m diameter which is scheduled to be in operation within two years.Comment: 5 pages, 1 figure, LaTeX 2.09 with aipproc.sty & epsfig.sty, to appear in proceedings of the 4th Compton Symposium, Williamsburg, 199

Neutron Resonance Spectroscopy of 103Rh from 30 eV to 2 keV

Neutron resonances in 103Rh have been measured for neutron energies from 30 to 2000 eV using the time-of-flight method and the (n,γ) reaction. The rhodium resonance spectroscopy is essential for the analysis of parity violation measurements recently performed on neutron resonances in 103Rh. Neutron scattering and radiative widths were determined, and orbital angular momentum assignments made with a Bayesian analysis. The s-wave and p-wave strength functions and average level spacings were determined

Parity Violation in Neutron Resonances of 103Rh

Parity nonconservation (PNC) was studied in p-wave neutron resonances of 103Rh in the neutron energy range 30 to 490 eV. The helicity dependence of the neutron total cross section of rhodium was determined by capture measurements with the time-of-flight method at the Manuel Lujan Neutron Scattering Center at the Los Alamos National Laboratory. A total of 32 p-wave resonances were studied and statistically significant longitudinal asymmetries were observed for resonances at En=44.5, 110.8, 321.6, and 432.9 eV. A statistical analysis treating the PNC matrix elements as random variables yields a weak spreading widthΓw=(1.42-0.59+1.21)×10-7eV

Neutron Resonance Spectroscopy of 104Pd, 105Pd, and 110Pd

We have measured neutron resonances in the palladium isotopes 104, 105, and 110 for neutron energies from 1 to 2100 eV. Many new p-wave resonances have been observed. Their neutron widths and, in several cases, the radiative widths were measured. The average level spacings and the s-wave and p-wave neutron strength functions were determined. The time-of-flight method was used for both neutron total cross section measurements and total (n,γ) reaction yield measurements at the pulsed spallation neutron source of Los Alamos Neutron Science Center. Well established resonance spectroscopy for these isotopes is essential for the analysis of parity violation data that were recently measured in palladium