The LIRAT low-energy beam facility at SPIRAL
Contact: J.-C. Thomas, GANIL
Schematic of the low-energy area of the SPIRAL facility. Primary beams enter from the top right of the figure and impinge the coupled target-and-ion-source(ECS1). Low-energy (10–30 keV) beams can then be delivered to the identification station  or the LPCtrap facility through the LIRAT line or they can be injected into the CIME cyclotron for experiments with post-accelerated beams.
The LIRAT acronym stands for "Ligne d'Ions Radioactifs A Très basse énergie". The implementation of a low-energy beam facility at SPIRAL was proposed in 1998 by G. Auger, B. Blank and C. Lebrun  with the aim to perform nuclear structure, fundamental interaction and solid state physics studies with the radioactive ion beams delivered by the SPIRAL target ion source system. The construction of the beam line started in 2001 with A. Peghaire as a project leader and a first radioactive beam of 19Ne1+ was delivered in 2005.
The LIRAT line delivers SPIRAL beams to the LPCtrap setup where fundamental interaction studies are performed. By 2018, the LIRAT line will transmit the SPIRAL beams to the DESIR facility.
The LIRAT line consists in a 45° dipole and in a set of magnetic quadrupoles and stearers driving with a efficiency better than 80 % 80 pi mm.mrad beams of less than 30 keV (See figure 1). The Brho is limited to 0.136 T.m, which allows to transport A < 89 ions in a single charge state. The optics was design in order to obtain a beam spot size of about 5 mm at the focal point.
At present, only 4 of the radioactive ion beams produced by SPIRAL can be used at the LIRAT facility. They are listed in table 1 where only the charge states associated with the largest intensities are considered. (see the SPIRAL beam web page for more details).
By 2016, all SPIRAL beams will be available, including beams of metallic ions and condensable elements being currently developed within the SPIRAL-Upgrade project.
Within the SPIRAL2 project, the LIRAT line will transport the SPIRAL beams to the DESIR facility.
Figure 1: The LIRAT line at SPIRAL
Table 1: Available beams at LIRAT
| 6He|| 1+|| 2.1x08|
| 19Ne|| 2+|| 1.5x108|
| 32Ar|| 9+|
| 35Ar|| 8+|
 G.F. Grinyer et al., Nucl. Inst. Meth. Phys. Res. A 741, 18 (2014).
 G. Auger, B. Blank and C. Lebrun, GANIL Scientific Committee, 1998.