Application of the time-of-flight spectrometer PILGRIM to mass measurements
Internship in experimental nuclear physics
The goal of the internship is to contribute to the test of the PILGRIM* time-of-flight spectrometer for its future application for precise mass measurements at S3.
S3 is the Super Separator Spectrometer, which will be one of the workhorses of SPIRAL2 at GANIL for producing N=Z and super-heavy elements (among other exotic nuclei) by fusion – evaporation and transfer reactions. The S3- Low Energy branch (S3-LEB) consists in a gas cell which stops and neutralizes the reaction residues. The isotopes of interest are then selectively laser – ionized, and then cooled by buffer gas, mass separated and bunched in successive RFQs. Finally the PILGRIM spectrometer permits an unambiguous identification of the isotopes produced and a rapid and accurate mass measurement of the isotopes of interest. The spin, nuclear moments and charge radii of the isotopes are optionally determined by laser spectroscopy at the gas cell. The measurement of these ground state properties (masses, spins, nuclear moments and charge radii) is of foremost importance for studying nuclear structure far away from stability. Especially, high precision mass measurements with PILGRIM at S3 would give hints on possible structural changes and allow testing nuclear models far away from stability, towards 100Sn or the island of stability of superheavy nuclei.
PILGRIM is a Multi-Reflection Time-of-Flight Mass Spectrometer (MR ToF MS) of latest generation which has first been demonstrated to work in the end of 2016. Its application for high precision mass measurements remains to be explored. During the internship, a number of systematic tests will be done with a stable ion source at LPC Caen for probing the mass accuracy that can be achieved with such a technique.
*Piège à Ions Linéaire du Ganil pour la Résolution des Isotopes et leur mesure de Masse
Expected skills: Skills in instrumentation, numerical methods, and communication will be valued, as well as curiosity
This internship leads to a PhD thesis.
Contact : Pierre DELAHAYE
GANIL, BP 5027, 14 076 Caen cedex 05
Tél. 02 31 45 44 56
Fax : 02 31 45 44 21
e-mail : delahaye_at_ganil.fr