Description
The HITRAP facility, located at the GSI
Helmholtzzentrum fuer Schwerionenforschung
GmbH in Darmstadt, Germany, is designed to
decelerate and cool heavy, highly charged ions
(HCI) created by the GSI accelerator complex
[1]. The system consists of a two-stage linear decelerator, followed by a cryogenic Penning-Malmberg trap
for subsequent ion cooling. The deceleration
stages reduce the ion energy from 4 MeV/u to
500 keV/u and to 6 keV/u respectively, before
forwarding a slow, but hot ion bunch towards the
cooling trap. The trap is operated in a so-called
nested configuration, in which the electrons, created
by an external photo-electron source, are
stored simultaneously with the HCI and serve
as a cold thermal bath. After cooling, the ions can be transported via
a low-energy transfer beamline towards various
attached experiments [2]. A dedicated small ion
source (Dresden EBIT) is attached to the beamline
and used for commissioning of the cooling
trap as well as a source of light HCI for attached experiments
[3]. So far, deceleration of heavy HCI has been set up down to 6 keV/u, though the
process is somwhat lengthy, hampered by a low
delivery rate of a single ion bunch per 40 seconds.
The subsequent electron cooling process is
under development with promising results. Ions
from the EBIT are regularly stored and mixed
with electrons. Recently, the first indications of electron cooling of locally-produced HCI in a Penning trap could be achieved, a major milestone towards heavy HCI at eV and sub-eV energies. The current status of this development as well as future aspects will be presented.
[1] Herfurth F et al 2015 Phys. Scr. 2015 014065
[2] Andelkovic Z et al 2015 Nucl. Instrum. Methods
Phys. Res. Section A vol. 795 2015 055
[3] Sokolov A et al 2010 JINST 5 C11001
