Cross sections for one-neutron knock-out from37Ca at intermediate energy

Abstract

The cross section for the knock-out of a deeply bound valence neutron from 37 Ca at an incident beam energy of 60A MeV has been measured along with momentum distributions of the residual nuclei and γ rays from the de-excitation of the first excited state in 36 Ca. 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 36 Ca indicate a sizable N = 16 gap.

Enhancement and Saturation of Near-Field Radiative Heat Transfer in Nanogaps between Metallic Surfaces

“…The present experiment confirms the energy of the 2 þ 1 state in 36 Ca [40,41], which is, using the precise value of Ref. [35], 245(2) keV lower than in 36 S. Populated by the ðp; dÞ reaction, it has a large C 2 S value with an L ¼ 0 angular distribution pattern, pointing to a pure 1p1h configuration with a hole in the 2s 1=2 orbital.…”

Broken mirror symmetry in $^{36}$S and $^{36}$Ca

“…For 36 Ca the only spectroscopic information available is the excitation energy of the first 2 + state [16] from refs. [14,15]. Note the very large experimental MED for the spherical 2 + state of -246(3) keV, at variance with the situation in the A = 38 mirrors, where the MED is +45 keV.…”

“…For the Z = 20 isotopes, 32 Ca most likely is experimentally out of reach, perhaps we can reach 34 Ca, and there is already some information about 36 Ca in refs. [14,15].…”

“…While the 36 Ca isotope is the heaviest acknowledged T z = −2 nucleus, just two neutrons away from the proton drip line, the 36 S is stable. The excitation energy of the 2 + state, for the N = 20 36 Ca isotope, was measured both at GSI [14] and GANIL [15] by using a knock-out reaction from a secondary 37 Ca beam. In these two experiments a unique γ was observed at an energy of 3015 (16) keV at GSI and 3036 (11) keV at GANIL.…”