KPH, Mainz, Germany
GSI, Darmstadt, Germany
HIM, Mainz, Germany
IKP, Mainz, Germany
MESA is a recirculating superconducting accelerator under construction at Johannes Gutenberg-Universität Mainz. It can be operated in either external beam or ERL mode and will be used for high precision particle physics experiments. The operating beam current and energy in EB mode is 0.15 mA with polarized electrons at 155 MeV. In ERL mode a polarized beam of 1 mA at 105 MeV will be available. In a later construction stage of MESA the beam current in ERL-mode shall be upgraded to 10 mA (unpolarized). Civil construction and commissioning of components like electron gun, LEBT and SRF modules have been started already. We will give a project overview including the accelerator layout, the current status and an outlook to the next construction and commissioning steps.
KPH, Mainz, Germany
GSI, Darmstadt, Germany
HIM, Mainz, Germany
The MESA project is currently under construction at Johannes Gutenberg-Universität Mainz. It will be used for high precision particle physics experiments in two different operation modes: external beam (EB) mode (0.15 mA; 155 MeV) and energy recovery (ERL) mode (1 mA; 105 MeV). The recirculating main linac follows the concept of a double sided accelerator design with vertical stacking of return arcs. Up to three recirculations are possible. Acceleration is done by four TESLA/XFEL 9-cell SRF cavities located in two modified ELBE cryomodules. Within this contribution the recirculation optics for MESA will be presented. Main goals are achieving best energy spread at the experimental setups in recirculating ERL and non-ERL operation and providing small beta-functions within the cryomodules for minimizing HOM excitation at high beam currents.
KPH, Mainz, Germany
HIM, Mainz, Germany
GSI, Darmstadt, Germany
The Mainz Energy-recovering Superconducting Accelerator (MESA) will be an electron accelerator allowing c.w. operation in energy-recovery (ER) mode. The energy gain of 50 MeV will be provided by two modified ELBE/Rossendorf-type cryomodules. The MESA-cryomodules are delivered and tested. The test results will be discussed.
TEMF, TU Darmstadt, Darmstadt, Germany
IKP, Mainz, Germany
For intense electron bunches traversing through bends, as for example the recirculation arcs of an Energy-Recovery Linac (ERL), dispersion matching with space charge of an arc into the subsequent radio-frequency (RF) structure is essential to maintain the beam quality. We show that beam envelopes and dispersion along the bends and recirculation arcs of an ERL, including space charge forces, can be matched to adjust the beam to the parameters of the subsequent section. The present study is focused on a small-scale, double-sided recirculating linac Mainz Energy-recovering Superconducting Accelerator (MESA). MESA is an under construction two pass ERL at the Johannes Gutenberg-Universit\"at Mainz, which should deliver a continuous wave (CW) beam at 105 MeV for physics experiments with a pseudo-internal target. In this work, a coupled transverse-longitudinal beam matrix approach for matching with space charge in MESA is employed.
