R.F. Parry

Beta-delayed two-proton decay of 26P

Abstract Beta-delayed emission of two protons has been observed in the decay of 26P. A two-proton summed energy group at 4.914 MeV was assigned to the decay to the 24Mg ground state following the superallowed beta-decay of 26P. The mechanism for two-proton emission has, in this case, been shown to be a sequential process.

Decay of a new isotope, 24Si: A test of the isobaric multiplet mass equation

Abstract Observation of beta-delayed protons from the decay of the mass separated T z =−2 nuclide 24 Si (t 1 2 ≈100 ms ) establishes the mass excess of the lowest T =2 (0 + ) state in 24 Al (5903±9 KeV). An excellent fit to the quadratic form of the isobaric multiplet mass equation is obtained.

Beta-delayed proton decay of the Tz = −2 isotope 26P☆

Abstract The 28Si(3He, p4n)26P reaction at 110–130 MeV has been used to discover the odd-odd Tz = −2 nuclide 26 P ( 1 2 ≈ 20 ms ) , which was predicted to lie on or beyond the proton drip line. Beta-delayed protons from its decay establish the mass excess of the lowest T = 2 state in 26Si as 5.936 ± 0.015 MeV. Possible beta-delayed two-proton emission from this isotope is discussed.

Advances in the helium-jet coupled on-line mass separator RAMA

General improvements to the on-line mass separator RAMA (Recoil Atom Mass Analyzer) have yielded a greater reliability and efficiency for some elements. A new utilitarian helium-jet chamber has been installed to facilitate quick target and degrader foil changes in addition to a new ion source holder. A higher efficiency hollow-cathode, cathode-extraction ion source, for lower melting point elements (< 1200/sup 0/C) has also been designed. Tests with the beta-delayed proton emitter /sup 37/Ca showed a factor of five increase in yield over the old hollow-cathode, anode-extraction source. A differentially-pumped-tape drive system compatible with both ..gamma..-..gamma.. and ..beta..-..gamma.. experiments has been incorporated into the general detection system. All major operating parameters will soon be monitored by a complete stand-alone microprocessor system which will eventually be upgraded to a closed-loop control system.