Erratum to: “Mass measurements on neutron-deficient Sr and neutron-rich Sn isotopes with the ISOLTRAP mass spectrometer” [Nucl. Phys. A 763 (2005) 45]

Mass measurements on neutron-deficient Sr and neutron-rich Sn isotopes with the ISOLTRAP mass spectrometer

Abstract The atomic masses of 76,77,80,81,86,88 Sr and 124,129,130,131,132 Sn were measured by means of the Penning trap mass spectrometer ISOLTRAP at ISOLDE/CERN. 76 Sr is now the heaviest N = Z nucleus for which the mass is measured to a precision better than 35 keV. For the tin isotopes in the close vicinity of the doubly magic nucleus 132 Sn, mass uncertainties below 20 keV were achieved. An atomic mass evaluation was carried out taking other experimental mass values into account by performing a least-squares adjustment. Some discrepancies between older experimental values and the ones reported here emerged and were resolved. The results of the new adjustment and their impact will be pr…

A linear radiofrequency quadrupole ion trap for the cooling and bunching of radioactive ion beams

A linear radiofrequency quadrupole ion guide and beam buncher has been installed at the ISOLTRAP mass spectrometry experiment at the ISOLDE facility at CERN. The apparatus is being used as a beam cooling, accumulation, and bunching system. It operates with a buffer gas that cools the injected ions and converts the quasicontinuous 60- keV beam from the ISOLDE facility to 2.5-keV beam pulses with improved normalized transverse emittance. Recent measurements suggest a capture efficiency of the ion guide of up to 40% and a cooling and bunching efficiency of at least 12% which is expected to still be increased. The improved ISOLTRAP setup has so far been used very successfully in three on-line e…

Direct mass measurements of neutron-deficient xenon isotopes with the ISOLTRAP mass spectrometer

Abstract The masses of Xe isotopes with 124⩾ A ⩾114 have been measured using the ISOLTRAP spectrometer at the on-line mass separator ISOLDE/CERN. A mass resolving power of 500 000 was chosen resulting in an accuracy of δm ≈12 keV for all isotopes investigated. Conflicts with existing mass data of several standard deviations were found.

A linear radiofrequency ion trap for accumulation, bunching, and emittance improvement of radioactive ion beams

An ion beam cooler and buncher has been developed for the manipulation of radioactive ion beams. The gas-filled linear radiofrequency ion trap system is installed at the Penning trap mass spectrometer ISOLTRAP at ISOLDE/CERN. Its purpose is toaccumulate the 60-keV continuous ISOLDE ion beam with high efficiency and to convert it into low-energy low-emittance ion pulses. The efficiency was found to exceed 10\,\% in agreement with simulations. A more than 10-fold reduction of the ISOLDE beam emittance can be achieved. The system has been used successfully for first on-line experiments. Its principle, setup and performance will be discussed. An ion beam cooler and buncher has been developed fo…

Direct mass measurements on neutron-deficient xenon isotopes with the ISOLTRAP mass spectrometer

The masses of Xe isotopes with 124 A 114 have been measured using the ISOLTRAP spectrometer at the on-line mass separator ISOLDE/CERN. A mass resolving power of 500000 was chosen resulting in an accuracy of m 12 keV for all isotopes investigated. Con icts with existing mass data of several standard deviations were found. peerReviewed

Breakdown of the Isobaric Multiplet Mass Equation atA=33,T=3/2

Mass measurements on ${}^{33,34,42,43}\mathrm{Ar}$ were performed using the Penning trap mass spectrometer ISOLTRAP and a newly constructed linear Paul trap. This arrangement allowed us, for the first time, to extend Penning trap mass measurements to nuclides with half-lives below one second ( ${}^{33}\mathrm{Ar}$: ${T}_{1/2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}174\mathrm{ms}$). A mass accuracy of about ${10}^{\ensuremath{-}7}$ $(\ensuremath{\delta}m\ensuremath{\approx}4\mathrm{keV})$ was achieved for all investigated nuclides. The isobaric multiplet mass equation was checked for the $A\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}33$, $T\phantom{\rule{0ex}{0ex}}=\phantom…

HITRAP: A Facility for Experiments with Trapped Highly Charged Ions

HITRAP is a planned ion trap facility for capturing and cooling of highly charged ions produced at GSI in the heavy-ion complex of the UNILAC-SIS accelerators and the ESR storage ring. In this facility heavy highly charged ions up to uranium will be available as bare nuclei, hydrogenlike ions or few-electron systems at low temperatures. The trap for receiving and studying these ions is designed for operation at extremely high vacuum by cooling to cryogenic temperatures. The stored highly charged ions can be investigated in the trap itself or can be extracted from the trap at energies up to about 10 keV/q. The proposed physics experiments are collision studies with highly charged ions at wel…

Accurate masses of neutron-deficient nuclides close to

Abstract Mass measurements with the Penning-trap mass spectrometer ISOLTRAP at ISOLDE/CERN are extended to nonsurface ionizable species using newly developed ion-beam bunching devices. Masses of 179–197Hg, 196,198Pb, 197Bi, 198Po and 203At were determined with an accuracy of 1×10 −7 corresponding to δm≈20  keV. Applying a resolving power of up to 3.7×10 6 ground and isomeric states of 185,187,191,193,197Hg were separated. First experimental values for the isomeric excitation energy of 187,191Hg are obtained. A least-squares adjustment has been performed and theoretical approaches are discussed to model the observed fine structure in the binding energy.

Towards Shorter-Lived Nuclides in ISOLTRAP Mass Measurements

Recently, the applicability of Penning trap mass spectrometry has been extended to nuclides with a half-life of less than one second. The mass of 33Ar(T 1/2 = 174 ms) was measured using the ISOLTRAP spectrometer with an accuracy of 4.2 keV. This measurement provided a stringent test of the Isobaric Multiplet Mass Equation (IMME) at mass number A = 33 and isospin T = 3/2. The fast measurement cycle that shows the way to other measurements of very-short-lived nuclides is presented. Furthermore, the results of the IMME test are displayed.

Extension of Penning-trap mass measurements to very short-lived nuclides

Abstract Mass measurements on 33,34,42,43 Ar have been performed at the ISOLTRAP spectrometer. An accuracy of δm ≈4 keV has been achieved for all measured isotopes. With 33 Ar it is the first time that a nuclide with a half-life shorter than one second has been investigated using a Penning trap. This became possible due to the recently installed linear radio-frequency ion-trap system and an improved, faster measurement cycle.

SHIPTRAP—a capture and storage facility for heavy radionuclides at GSI

Abstract SHIPTRAP will be an ion-trap facility for heavy radionuclides delivered from SHIP. Ion traps are a perfect instrument for precision measurements since the ions can be cooled to an extremely small phase space and can be stored for a very long time. In addition one can achieve very high purity by removing contaminant ions. SHIPTRAP will extend the possibilities of measurements in traps to transuranium nuclides and provide cooled and isobarically pure ion bunches.

Status of the SHIPTRAP Project: A Capture and Storage Facility for Heavy Radionuclides from SHIP

The ion trap facility SHIPTRAP is being set up to deliver very clean and cool beams of singly-charged recoil ions produced at the SHIP velocity filter at GSI Darmstadt. SHIPTRAP consists of a gas cell for stopping and thermalizing high-energy recoil ions from SHIP, an rf ion guide for extraction of the ions from the gas cell, a linear rf trap for accumulation and bunching of the ions, and a Penning trap for isobaric purification. The progress in testing the rf ion guide is reported. A transmission of about 93(5)% was achieved.

Mass measurements on unstable Sn and Sr isotopes with the ISOLTRAP mass spectrometer

Direct mass measurements have been performed on the isotopes 76,77,80,81Sr and 129,130,131,132Sn by means of the Penning trap mass spectrometer ISOLTRAP at ISOLDE/CERN. In the case of 76Sr the mass was measured for the first time and an accuracy of about 30 keV was reached (Fig. 1). The masses of the tin isotopes are known for a long time from Q β measurements.