Measurements of?-endpoint-energies using a magnetic electron separator

Abstract

Beta endpoint energies of the short-lived neutron rich fission products 9~ have been measured using a newly constructed achromat!c magnetic electron-separator that eliminates low energy electrons. Thus only electrons in the neighbourhood of the fl-endpoint are recorded in a low background environment. PACS: 21.o0, 25.85

Penning-trap mass spectrometry of highly charged, neutron-rich Rb and Sr isotopes in the vicinity ofA≈100

“…The scenario for 98 Sr is similar where our value with -66424.5(4.0) keV is in agreement within the error of JYFLTRAP [16] and more precise, but disagrees with AME03 [22] by 221 keV (8.4σ deviation). AME03 adopted its value from β end-point energy ex- [53,54].…”

“…The previous measurements considered in AME03 were based on β end-point energies from 97 Rb(β − ) 97 Sr. The adjusted Q-value, including the TITAN input, is now 10063(4) keV, compared to the other measurements: 10020(50) keV [51] (0.9σ deviation), 10450(30) keV [52] (12.9σ deviation), 10440 (60) keV [53] (6.3σ deviation), and 10462 (40) keV [54] (10.0σ deviation). The TI-TAN mass value validates the first measurement [51] and greatly improves the precision of the Q-value and mass.…”

“…Our measured mass excess is -54318.4(3.4) keV and differs from the adopted value in AME03 [22] of -54221.6(50.2) keV by 97 keV or 1.9σ deviation. The previous mass excess was determined from the end-point energy of the β spectrum of 98 Rb(β − ) 98 Sr [53,54] with 80.4% weight and from the triplet measurement of ( 97 Rb, 98 Rb, 95 Rb) [55] with 19.6% weight.…”

“…If both are present the solid lines indicate the line shapes for the resonance. If the yield of the isomer is a factor of 20 (5) less than for the ground state, the resonance line shape is displayed with a solid black (red) line.periments, with 95.5% from 98 Sr(β − ) 98 Y [52] and 4.5% from 98 Rb(β − ) 98 Sr[53,54].…”