First Offline Results from the S3 Low-Energy Branch

Jekabs Romans,Iain Moore,Sandro Kraemer,Frederic Boumard,Olivier Pochon,Christophe Vandamme,Philippe Desrues,Patricia Duchesne,Arno Claessens,Anjali Ajayakumar,J.f Cam ,E Verstraelen ,M Vandebrouck ,A Ortiz-Cortes ,L Càceres ,A Drouart ,E Traykov ,P Delahaye ,P Van Duppen ,V Manea ,R P De Groote ,M Authier ,R Leroy ,S Damoy ,N Lecesne ,X Fléchard ,P Gangnant ,S Franchoo ,J Lory ,J Uusitalo ,F Lutton ,S Sels ,R Ferrer ,P Van Den Bergh ,B Osmond ,H Savajols ,B M Retailleau ,M Verlinde ,Y Merrer ,J Piot ,Κ Wendt

doi:10.3390/atoms10010021

Abstract

We present the first results obtained from the S3 Low-Energy Branch, the gas cell setup at SPIRAL2-GANIL, which will be installed behind the S3 spectrometer for atomic and nuclear spectroscopy studies of exotic nuclei. The installation is currently being commissioned offline, with the aim to establish optimum conditions for the operation of the radio frequency quadrupole ion guides, mass separation and ion bunching, providing high-efficiency and low-energy spatial spread for the isotopes of interest. Transmission and mass-resolving power measurements are presented for the different components of the S3-LEB setup. In addition, a single-longitudinal-mode, injection-locked, pumped pulsed-titanium–sapphire laser system has been recently implemented and is used for the first proof-of-principle measurements in an offline laser laboratory. Laser spectroscopy measurements of erbium, which is the commissioning case of the S3 spectrometer, are presented using the 4f126s23H6→4f12(3H)6s6p optical transition.

Highlights

The Super Separator Spectrometer (S3) [1] is a fusion–evaporation recoil separator, which is currently under construction at the SPIRAL2 facility in GANIL, aiming to study exotic neutron-deficient isotopes in the actinide and super-heavy element regions, and in the N = Z region around 100Sn [2]
For the tests of the shape RFQ (SRFQ)/mRFQ section, a 133Cs source was inserted on a linear actuator in the designed area for the gas jet formation
The RF driving frequency of the ion guiding radio frequency quadrupole (RFQ) was set to 500 kHz, to allow operation with lower RF amplitudes and avoid discharges

Summary

Introduction

The low-production crosssections and the available primary beam intensities at various facilities worldwide limits the production rates, and the amount of experimental data of very exotic nuclear systems To overcome this obstacle, the superconducting LINAC of the SPIRAL2 facility has been developed to produce stable ion beams from He to U with energies from 0.75 up to 14.5 MeV/u, and intensities from 1pμA up to Ni [1]. A crucial upgrade for the IGLIS technique has been the use of a de Laval nozzle at the exit of the gas cell, which creates a collimated and homogeneous hypersonic gas jet of low temperature T and low density ρ [6], containing the products of interest Such an environment allows for laser spectroscopy with reduced broadening mechanisms by about an order of magnitude, while maintaining a high selectivity and efficiency [5]. The S3-LEB setup will be described and some first results from the offline commissioning tests will be presented

The S3 Low-Energy Branch

The GISELE Laser Laboratory

RFQ Offline Tests

Experimental results

Laser Ion Source Offline Tests

Outlook and Conclusions