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[en] Complete text of publication follows. Isospin symmetry is a consequence of the approximate charge invariance of nucleon-nucleon forces. The strong interaction conserves the charge symmetry very well and the Coulomb energies are almost state-independent in a nucleus. The large bulk displacement energies produced by the monopole part of the Coulomb ?eld are approximately cancelled in the excitation energy differences of the mirror nuclei. As a result, energy spectra are quite analogous between mirror nuclei. A small Coulomb effect may remain, due to differences in the radii of the single particle states. Especially, when the proton states are weakly bound, the wave function of the protons in the last shell becomes wider due to larger penetration to the classically forbidden region and consequently the Coulomb energy decreases. In the neutron-deficient 36Ca, the 21+ state is expected to be unbound by about 500 keV, which may allow for a larger extension of the proton orbits. A measure of the increase of the proton radius may be the lowering of the energy of the 21+ state in 36Ca relative to the position of the same state in the mirror nucleus 36S. To check if this happens, an experiment was performed at GANIL in Caen, France. During the experiment the primary 40Ca beam of around 95 A x MeV was fragmented in the SISSI target. The resulting beam cocktail was purified in the 'α' spectrometer consisting of two dipole magnets and a degrader with the setting optimised for 37Ca. The fragments were identified event by event through a time-of-flight measurement between the spectrometer and the secondary 9Be target of 1072 μm thickness, in which further nucleons were removed at an energy of around 61 A x MeV. After passing through the target, the produced fragments were identified using the spectrometer SPEG by time-of-flight and energy loss measurements. To detect the emitted gamma rays, the Chateau de Cristal array consisting of 74 BaF2 scintillators was placed around the Be target. The Doppler-corrected gamma-ray spectrum obtained for 36Ca is shown in fig. 1. Using Gaussian fits for the peaks, the energy of the 2+ state in 36Ca has been determined to be E(2+) 3050(60) keV, 240 keV lower than the corresponding value in 36S much larger than the usual mirror energy differences, indicating a drip line effect. (author)
Journal
[en] We measure the mass of the lowest T=2 state in 36K by observing β-delayed protons following the superallowed 36Ca decay and use this result to make a precise test of the isobaric multiplet mass equation
Journal
[en] The cross section for the knock-out of a deeply bound valence neutron from 37Ca at an incident beam energy of 60 A MeV has been measured along with momentum distributions of the residual nuclei and? rays from the de-excitation of the first excited state in 36Ca. As for other cases of deeply bound nucleons studied using knock-out reactions, the reduction of the measured cross section compared to theoretical predictions is stronger than those observed for near-magic stable nuclei. Both the momentum distributions and the excitation energy of the first excited state in 36Ca indicate a sizable N = 16 gap. (authors)
Journal
Physical Review. C, Nuclear Physics; ISSN 0556-2813; 
; v. 86; p. 064609.1-064609.5
; v. 86; p. 064609.1-064609.5
[en] An experiment was performed to study excited states in neutron-deficient nuclei around Ca. After a first fragmentation of the primary beam, the one-neutron knockout reaction was used to produce 36Ca ions from the 37Ca secondary beam and in-beam γ rays were measured. The energy of the first excited 2+ state in 36Ca and the cross section for the 1-neutron knock-out reaction from 37Ca at ∼ 45 A MeV were obtained. The 2+ energy in 36Ca is compared to the mirror nucleus 36S to deduce information on the isospin dependence of the nuclear force near the proton drip line. Furthermore, for two other Tz=-2 nuclei, 28S and 32Ar, the deexcitation of the first 2+ states has been observed. (author)
Journal
Acta Physica Polonica. Series B; ISSN 0587-4254; ; v. B38(4); p. 1353-1357
; v. B38(4); p. 1353-1357
[en] Continuum-coupling correction to binding energies in neutron rich oxygen and fluorine isotopes and to excitation energies of 2+1 states in 36Ca and 36S mirror nuclei are studied using the real-energy continuum shell model. (author)
Journal
Acta Physica Polonica. Series B; ISSN 0587-4254; ; v. B39(2); p. 389-400
; v. B39(2); p. 389-400
[en] We give a description for the production of 13C foils and the preparation of an approximately 1-mg/cm2 thick target. A recent experiment to measure the mass of 36Ca, via the 40Ca(4He,8He)36Ca reaction, required precise determination of the accelerated beam energy and calibration of the focal plane of a magnetic spectrometer to achieve the most accurate value for the 36Ca mass. A 1 mg/cm213C target was essential for these purposes. Target preparation and performance along with some preliminary results will be discussed
Journal
Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment; ISSN 0168-9002; ; CODEN NIMAER; v. 438(1); p. 52-57
; CODEN NIMAER; v. 438(1); p. 52-57
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