Mass is one of the fundamental properties of atomic nuclei. Isochronous mass spectrometry (IMS), using astorage ring combined with an in-flight separator, has been shown to be a powerful tool for mass measurementof ex...Mass is one of the fundamental properties of atomic nuclei. Isochronous mass spectrometry (IMS), using astorage ring combined with an in-flight separator, has been shown to be a powerful tool for mass measurementof exotic nuclei[1]. Recently, masses of many proton-rich nuclides were accurately determined at the HIRFL-CSRfacility[2]. In this paper, we described the first isochronous mass measurement of neutron-rich nuclides at CSRe.This experiment was performed at the end of 2011. In the experiment, the primary beam of 86Kr28+ ions wasaccumulated and accelerated to an energy of 460.65 MeV/u in the synchrotron CSRm. The 86Kr28+ ions were fastextracted and focused on a 15 mm thick beryllium target which was placed at the entrance of the RIBLL2 (anin-flight fragment separator).展开更多
In this paper, we present direct mass measurements of neutron-rich86 Kr projectile fragments conducted at the HIRFL-CSR facility in Lanzhou by employing the Isochronous Mass Spectrometry(IMS) method. The new mass exce...In this paper, we present direct mass measurements of neutron-rich86 Kr projectile fragments conducted at the HIRFL-CSR facility in Lanzhou by employing the Isochronous Mass Spectrometry(IMS) method. The new mass excesses of52-54 Sc nuclides are determined to be-40492(82),-38928(114),-34654(540) ke V, which show a significant increase of binding energy compared to the reported ones in the Atomic Mass Evaluation 2012(AME12).In particular,53 Sc and54Sc are more bound by 0.8 Me V and 1.0 Me V, respectively. The behavior of the two neutron separation energy with neutron numbers indicates a strong sub-shell closure at neutron number N =32 in Sc isotopes.展开更多
文摘Mass is one of the fundamental properties of atomic nuclei. Isochronous mass spectrometry (IMS), using astorage ring combined with an in-flight separator, has been shown to be a powerful tool for mass measurementof exotic nuclei[1]. Recently, masses of many proton-rich nuclides were accurately determined at the HIRFL-CSRfacility[2]. In this paper, we described the first isochronous mass measurement of neutron-rich nuclides at CSRe.This experiment was performed at the end of 2011. In the experiment, the primary beam of 86Kr28+ ions wasaccumulated and accelerated to an energy of 460.65 MeV/u in the synchrotron CSRm. The 86Kr28+ ions were fastextracted and focused on a 15 mm thick beryllium target which was placed at the entrance of the RIBLL2 (anin-flight fragment separator).
基金Supported by 973 Program of China(2013CB834401)the NSFC(U1232208,U1432125,11205205,11035007)the Helmholtz-CAS Joint Research Group(HCJRG-108)
文摘In this paper, we present direct mass measurements of neutron-rich86 Kr projectile fragments conducted at the HIRFL-CSR facility in Lanzhou by employing the Isochronous Mass Spectrometry(IMS) method. The new mass excesses of52-54 Sc nuclides are determined to be-40492(82),-38928(114),-34654(540) ke V, which show a significant increase of binding energy compared to the reported ones in the Atomic Mass Evaluation 2012(AME12).In particular,53 Sc and54Sc are more bound by 0.8 Me V and 1.0 Me V, respectively. The behavior of the two neutron separation energy with neutron numbers indicates a strong sub-shell closure at neutron number N =32 in Sc isotopes.
