IPAC'23 - Particle Accelerator Projects and Upgrades

IPAC’23 / PARTICLE ACCELERATOR PROJECTS AND UPGRADES 16 Project Region EMEA Project Location Karlsruhe Project Type New Project Project Description The cSTART project at KIT aims to demonstrate, that injection of electron beams with parameters similar to laser-plasma- accelerated beams into a novel compact storage ring is feasible. Furthermore, the project aims to demonstrate the storage of ultra-short electron bunches and study their non-equilibrium dynamics. A cornerstone of the cSTART project is, therefore, the Very Large Acceptance compact Storage Ring VLA-cSR with its large momentum acceptance and flexible magnetic lattice. The non-ramping VLA-cSR will have the existing linac-based accelerator FLUTE as injector for tests with controlled beams with parameters close to potential future low-energy laser plasma accelerators. The bunches delivered by FLUTE cover a charge range from 1 pC up to 1 nC and a bunch length (duration) regime from 3 μm (10 fs) to 300 μm (1 ps) within an operational energy range from 40 to 60MeV. To store bunches with such a wide range of parameters, a novel compact storage ring with very large momentum acceptance is required. VLA-cSR must be compact enough to fit within the existing hall (about 15 by 14.5m) and has to be constructed at a height of about 4m. The three orders of magnitude covered by both the bunch charge and bunch length also pose a challenge to the turn- by-turn beam diagnostics. Due to the low electron energy, synchrotron radiation will not be available for stimulating the photodesorption process on the vacuum chamber surfaces and to achieve with this a vacuum quality of better than 10−8mb  r in VLA-cSR. For the same reason, synchrotron radiation damping is negligible, which requires an onaxis one- turn injection. The swap-out extraction requires a dedicated beam dump. An artistic view of VLA-cSR and the transfer line between the FLUTE and VLA-cSR is shown in https://www.ibpt. kit.edu/p_cSTART.php (https://www.ibpt.kit.edu/cstart) The main parameters of the VLA-cSR can be found in the follwing table: compact STorage ring for Accelerator Research and Technology at KIT, Germany