  The development of the new RFQ Cooler, called SHIRaC, was carried out. As a
part of SPIRAL 2 facility, SHIRaC aims to handle and cool typical SPIRAL 2
beams with large emittances (up to 80 pi.mm.mrad) and high currents (up to 1
uA). Its purposes are to enhance as much as possible the beam quality
(transverse geometric emittance of less than 3 pi.mm.mrad and longitudinal
energy spread close to 1 eV) and to transmit more than 60 % of ions.
  Numerical simulations and experimental studies have shown that the required
beam quality can be reached only in term of the emittance. The energy spread is
very far from expected values. It is sensitive to the space charge and the
buffer gas diffusion and more importantly to the RF field derivative effect.
The latter arises at the RFQ exit and increases with the RF parameters (the
frequency and the amplitude of the RF voltage).
  Studies allowing to enhance the cooled beam quality, mainly the energy spread
reduction, are presented and discussed along this paper. They consist in
implementing a miniature RFQ at the RFQ exit. Using this method, it becomes
possible to improve the cooled beam quality and to reach 1 eV of longitudinal
energy spread and around 1.75 {\pi}.mm.mrad of transverse geometric emittance
for beam currents going up to 1 uA.
  The transport of the cooled beam from SHIRaC towards a HRS has been done with
an electrostatic quadrupole triplet. Simulations and first experimental tests
showed that more than 95 % of cooled beams can reach the HRS.
  Finally, developments related to the nuclearization protection methods aiming
to avoid the escape of any nuclear matter from the SHIRaC beamline are studied.
