Description

The DESIR (Decay, Excitation and Storage of Radioactive Ions) low-energy beam
facility is currently under installation at GANIL in Caen, France. It is designed to
deliver high-impact science across nuclear structure, nuclear astrophysics,
fundamental interactions, and related fields. The beam preparation and purification
devices are the first devices expected to be available at the DESIR facility. These
include a general purpose ion buncher and cooler (GPIB [1]) and a double Penning
trap (PIPERADE [2]) both currently undergoing commissioning at LP2i Bordeaux and
scheduled for installation at GANIL in 2027. Complementing these, a multi-reflection
time-of-flight mass spectrometer (MR-TOF-MS) will be developed. The MR-TOF-MS
is a versatile and powerful instrument that will play a dual role at DESIR: as a fast
isobaric purification stage, capable of separating exotic ion species in just a few
milliseconds, and as a standalone high-precision mass measurement device.
The successful candidate will contribute to both instrumentation development and
forefront nuclear physics research with:
-The development of the MR-TOF-MS: designing, assembling, and commissioning
the spectrometer in close collaboration with LPC Caen, optimizing its ion-optical
performance, and integrating it into the DESIR beam line infrastructure.
-The data collection and analysis related to astrophysical phenomena. A key
question addressed concerns the explosion mechanism of core-collapse
supernovae. Uncertainties in the nuclear reactions governing the production and
destruction of ⁴⁴Ti represent a significant bottleneck in our understanding of these
events. Precise mass measurements of ⁴⊃3;Sc and ⁴⁶Cr are essential to constrain the
relevant reaction rates. These measurements will be carried out at the IGISOL
facility (University of Jyväskylä, Finland), using the JYFLTRAP Penning trap and
their operational MR-TOF-MS — giving the candidate direct exposure to a mature
system that mirrors in several respects the one they will be building at GANIL.
In addition, the student will have the opportunity to participate in the installation and
commissioning of PIPERADE and the GPIB at GANIL, carried out in collaboration
with the LP2i Bordeaux group. This will give the candidate direct experience with
complementary trapping and cooling technologies central to the DESIR facility.
The student will be encouraged to present the results in national and international
conferences and in peer reviewed journals. We aim to provide an open, inclusive,
and respectful working environment, and to help students build a solid foundation for
their future career, both within and beyond academia.
The candidate will join the FINDS (Fundamental Interactions aNd Dark Sectors)
group within the DPHY division at GANIL. This 36 months PhD position is funded by
the CaeSAR project, which benefits from state funding managed by the Agence
Nationale de la Recherche under the France 2030 programme (reference ANR-23-
EXES-0001), and from the Normandy region

Skills required

A master degree in physics is required. Experience in experimental nuclear physics, simulation or data analysis is desirable. The candidate must have good communication skills and the ability to work in collaborative, multidisciplinary projects. Fluency in spoken and written English is essential.

Bibliography

[1] “The General Purpose Ion Buncher: a radiofrequency quadrupole cooler-buncher for DESIR at SPIRAL2”: M. Gerbaux et al., NIM A 1046, 167631 (2023) - https://hal.science/hal-03815181v1 [2] “PIPERADE: A double Penning trap for mass separation and mass spectrometry at DESIR/SPIRAL2”: P. Ascher et al., NIM A 1019, 165857 (2021) - https://hal.archives-ouvertes.fr/hal-03390279