The internal multiphase target design for storage ring experiments

Recent modification of the internal target source setup at the experimental storage ring (ESR) led to a significant improvement of its performance. In particular, a reliable operation of the light target gases helium and hydrogen at unprecedented area densities up to values of 1014 cm-2 was demonstrated [1]. In the course of these optimization efforts, a remarkably versatile target source was established, enabling operation over the whole range of desired target gases (from H2 to Xe) and area densities (~1010 to ~1014 cm-2).

For more general, future applications at storage rings a completely new inlet chamber was proposed based on the experience gained during previous modification processes [2]. The much more compact chamber design will maintain the demanding storage ring vacuum requirements while enabling the operation of the target beam at an interaction length down to 1 mm. This is of paramount importance with respect to the realization of high precision experiments, e.g. by reducing the inaccuracy of the observation angle causing the relativistic Doppler broadening [3].

The new inlet chamber design is currently being assembled and commissioned at GSI. A thorough investigation of the exact target properties is mandatory prior to the deployment of this design as a unified target station at the storage rings of the FAIR facility.

References / Selected Publications






Low-Z internal target from a cryogenically cooled liquid microjet source

M. Kühnel et. al.

Nucl. Instr. Meth. A v 602 n 2 pp 311 (2009)


Prototype internal target design for storage ring experiments

N. Petridis et. al.

Phys. Scr. T166, 014051 (2015)


Applications of position sensitive germanium detectors for X-ray spectroscopy of highly charged heavy ions

Th. Stöhlker et. al.

Nucl. Instr. Meth. B 205, 210 (2003)