R.J. Ellis

Precise atomic mass difference determinations between some stable isotopes of Ge, As and Se

Abstract The 1 m radius, high-resolution mass spectrometer at the University of Manitoba (“Manitoba II”) has been used to determine 11 atomic mass differences between some stable isotopes of Ge, As and Se. These values are of greater accuracy and precision than existing data. Their consistency has been checked by a major least-squares adjustment involving relevant data in the region. Results include improved S2n values for several nuclides and the energies available for the ββ decays of 76Ge and 74Se, respectively.

Energy available for the double beta-decay of 76Ge

Abstract The Manitoba II high-resolution mass spectrometer has been used to determine the atomic mass difference 76 Ge − 76 Se = 2040.71 ± 0.52 keV . This result, which is superior in precision and accuracy to previous values, should facilitate current searches for the neutrinoless double beta-decay of 76Ge.

Atomic mass of 180Ta, a naturally occurring isomer

Abstract The Manitoba II high-resolution mass spectrometer has been used to determine atomic mass differences between isotopes of Hf, Ta and W. The new values confirm that the 10 13 y state of 180 Ta is a naturally occurring excited state.

Atomic mass differences in gadolinium and terbium and the K-capture of 158Tb as an indicator of neutrino mass☆

Abstract A high-resolution mass spectrometer has been used to determine six precise atomic mass differences in gadolinium and terbium. These are combined with nuclear reaction and decay Q -values in a least-squares adjustment to give “best” values for the mass differences. The Q EC -value of 1220.64±0.83 keV for 158 Tb precludes K-capture to the 1187 keV state in 158 Gd.

Precise atomic mass determinations at mass 124

Abstract The Manitoba II high-resolution mass spectrometer has been used to determine eight precise atomic mass differences amongst 124 Sn, 124 Te, 124 Xe, 13 C 37 Cl 3 and 54 Fe 35 Cl 2 . Precise values have been derived for the double β- decay energies of 124 Xe and 124 Sn and for the masses of 124 Sn, 124 Te, 124 Xe and 54 Fe. The precision of the mass of 124 Xe has been improved by a factor of ≈150.

Atomic Mass Determinations at the University of Manitoba

We have, in our laboratory, two large mass spectrometers which may be operated routinely with a resolving power of 100,000 or more. The older and larger instrument1 (“Manitoba I”) has a 2.7 m radius and is of a modified Dempster geometry. While it was not used for the work reported here, it is currently in operation and is being used to extend some of these measurements.

The precise atomic masses of 10B and 11B

Abstract A high-resolution mass spectrometer (“Manitoba II”) has been used to determine the precise atomic masses of 10 B and 11 B. These new values are 10 012937.32 λ 0.57 μu and 11 009303.09 ± 1.30 μu, respectively.

Operation of a long helium jet transport system with solid, monodisperse aerosols

Solid, monodisperse aerosols of NaCl, KCl, and AgCl have been used in a helium jet capillary system to transport unstable nuclides of Cu, Zn, Ga, and Sb a distance of 110 m. Overall transport efficiencies of ~ 60% have been achieved.