Mass measurements in the endpoint region of the rp-process at SHIPTRAP

Abstract

The Penning-trap mass spectrometer SHIPTRAP was designed for precision\ud mass measurements of radionuclides produced in fusion–evaporation reactions.\ud The latest measurement campaign covered heavy nuclei (A > 90) related to the\ud astrophysical rapid proton capture process. The masses of 34 neutron-deficient\ud radionuclides have been measured since February 2006 with relative uncertainties\ud between 5 × 10−8 and 1 × 10−7. Furthermore, the use of an octupolar RF excitation\ud for the time-of-flight ion-cyclotron-resonance technique was investigated and an\ud increase of the resolving power by a factor of ten was observed in agreement with\ud simulations. This will allow to resolve isomeric states with excitation energies of a\ud few 10 keV only

Nuclear astrophysics with radioactive beams

“…Relative mass uncertainties of order 10 −8 are routinely achieved. The Penning trap setups used for mass spectrometry of exotic nuclei are ISOLTRAP [458,459] at CERN/ISOLDE (Switzerland), CPT [460,461] at ANL (US), SHIPTRAP [462][463][464] at GSI (Germany), JYFLTRAP [465,466] at Jyväskylä (Finland), LEBIT [467][468][469] at NSCL (US) and TITAN [470] at TRIUMF (Canada). At GSI, rare-isotopes are produced in-flight, selected in the Fragment Separator (FRS) and subsequently injected into the Experimental Storage Ring (ESR) [471].…”

“…One-proton separation energies were derived and the low value for 106 Sb excludes a strong SnSbTe cycle starting at 105 Sn [497]. Masses of 34 neutron-deficient nuclei along the rp-process path were measured with SHIPTRAP at GSI with an uncertainty of 10 keV [464]. The nuclei relevant for the rp-process path above A = 90 were produced in fusionevaporation reactions induced by 40 Ca, 50 Cr and 58 Ni beams impinging upon a 58 Ni target.…”

“…The rp process proceeds along the Sn isotopic chain until the proton separation energy of Sb isotopes becomes large enough to delay the competing photodisintegration and hence, causes the rp process to proceed up to tellurium where SnSbTe cycles prevent the production of heavier elements. With the masses measured at SHIPTRAP, more accurate proton separation energies can be deduced in order to clarify which SnSbTe cycle dominates [464]. The Q values for the proton emission from 104 Sb and 105 Sb were also recently deduced indirectly from α-decay measurements carried out at HRIBF (ORNL) [498].…”

Current Status of r-Process Nucleosynthesis

“…Early measurements of 147 Ho + , 147 Er + , and 148 Er + were determined for the first time using SHIP-TRAP [154]. Subsequent measurements have concentrated on proton-rich nuclei relevant to the endpoint of the rp-process [155].…”

Low-power radio-frequency excitation as a plasma source in a Penning–Malmberg trap: a systematic study

“…Together with ultra-high vacuum (UHV) conditions these characteristic features allow long-time confinement as well as precise control and manipulation of particle samples. Successful applications of traps span a wide range of research fields, from accurate measurements of fundamental properties of charged species like highly-charged ions, radioactive nuclides, antimatter (Brown & Gabrielse 1986;Blaum 2006;Block et al 2006;Herfurth et al 2006;Aghion et al 2014;Saitoh et al 2014) to collective properties of non-neutral plasmas (see e.g. Davidson 1990;Driscoll & Fine 1990;Durkin & Fajans 2000;Romé & Lepreti 2011;Lepreti et al 2013) and beams (Bettega et al 2004;Paroli et al 2010aParoli et al , 2012.…”