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Antoine Lemasson

Publications and source records attributed to Antoine Lemasson.

3 recordsLinked to original sources

Unbound states in $^{19}$O(d,p$γ$)$^{20}$O: tracing the $ν$(d$_{3/2}$) orbital

The single-neutron transfer reaction $^{19}$O(d,p$γ$)$^{20}$O has been performed at GANIL, populating states up to and above the neutron separation energy. Bound states populated by s-wave and d-wave transfer have been observed with improved experimental angular distributions. Critically, several unbound states between 7.6 MeV and 9.8 MeV have been accessed for the first time through the 19O(d,p) channel, and isolated via particle-$γ$ spectroscopy.

nucl-ex

Direct proton transfer on $^{46}$Ar supports the presence of a charge density bubble linked to a novel nuclear structure below $^{48}$Ca

The $^{46}$Ar($^3$He,d)$^{47}$K reaction was performed in inverse kinematics using a radioactive $^{46}$Ar beam produced by the SPIRAL1 facility at GANIL and a cryogenic $^{3}$He target. The AGATA-MUGAST-VAMOS setup allowed the coincident measurement of the $γ$ rays, deuterons and recoiling $^{47}$K isotopes produced by the reaction. The relative cross sections towards the proton-addition states in $^{47}$K point towards a depletion of the $πs_{1/2}$ shell. The experimental findings are in good agreement with ab initio calculations, which predict that $^{46}$Ar exhibits a charge density bubble associated with a pronounced proton closed-shell character.

nucl-ex

Dual Position Sensitive MWPC for tracking reaction products at VAMOS++

The characteristics and performance of a Dual Position Sensitive Multi-Wire Proportional Counter (DPS-MWPC) used to measure the scattering angle, interaction position on the target and the velocity of reaction products, detected in the VAMOS++ magnetic spectrometer, are reported. The detector consists of a pair of position sensitive low pressure MWPCs and provides both fast timing signals, along with the two-dimensional position coordinates required to define the trajectory of the reaction products. A time-of-flight resolution of 305(11) ps (FWHM) was measured. The measured resolutions (FWHM) were 2.5(3) mrad and 560(70) μm for the scattering angle and the interaction point at the target respectively. The subsequent improvement of the Doppler correction of the energy of the gamma-rays, detected in the gamma-ray tracking array AGATA in coincidence with isotopically identified ions in VAMOS++, is also discussed.

physics.ins-det