Measurement of 19Ne spectroscopic properties via a new method of inelastic scattering to study novae

F R H Du Boulay ,J Grinyer,O Kamalou,P Delahaye,C Schmitt,L Acosta,C Rodríguez‐Tajes ,E Traykov,A Laird,D Ramos,Á M Sánchez-Benítez ,L Achouri,A Lemasson,F De Oliveira Santos,C Borcea,M Rejmund,F Negoiţă ,N De Séréville,F Rotaru,P Ujić ,G Marquínez-Durán ,M Stănoiu ,G De France,O Sorlin,Vincent Margerin ,B Bastin,M Ciemała ,A Estradé ,B Jacquot,T Davinson,J C Thomas ,J Mrázek ,P J Woods

doi:10.1088/1742-6596/940/1/012003

Abstract

The accuracy of the predictions of the γ flux produced by a classical nova during the first hours after the outburst is limited by the uncertainties on several reaction rates, including the 18F(p,α)15O one. Better constraints on this reaction rate can be obtained by determining the spectroscopic properties of the compound nucleus 19Ne. This was achieved in a new inelastic scattering method using a 19Ne radioactive beam (produced by the GANIL-SPIRAL 1 facility) impinging onto a proton target. The experiment was performed at the VAMOS spectrometer. In this article the performances (excitation energy range covered and excitation energy resolution) and limitations of the new technique are discussed. Excitation energy resolution of σ = 33 keV and low background were obtained with this inverse kinematics method, which will allow extracting the spectroscopic properties of 19Ne.

Highlights

The classical description of a nova consists of an explosion that occurs in a binary system of stars
The amplitude of the excitation energy spectrum was normalized to the beam time and corrected relative to the contribution of the carbon in the target
Measurements with a 0.4 μm thick carbon target were realized and pointed out a background level compatible with zero

Summary

Introduction

The classical description of a nova consists of an explosion that occurs in a binary system of stars. Excitation energy The large magnetic rigidity acceptance of VAMOS allowed measuring coincidences of p’ scattered particles with α and p” decay particles in a wide excitation energy range from 4.5 to 8.5 MeV (see Fig. 2) and from 7 to 8.5 MeV respectively. With this setup resolutions of 44 keV at 4.5 MeV to 33 keV at 8.1 MeV were achieved. 0.3 of the excitation energy deduced from a simulation in the case the proton p’ is detected by VAMOS in coincidence with decaying α particles recorded in the CD-PAD (black curve). Same work has been completed in the case of coincidences of p’ with p” decay particles

Benchmarking of the new technique

Findings

Conclusions