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.
TUCOYBS04
KPH, Mainz, Germany
MESA and BERLinPro are two Energy Recovery Linac (ERL) projects, both currently under construction at Germany. Both projects are running on the TESLA operation frequency of 1.3 GHz. Despite the different goals for future operation and achievable beam current the main linac cryomodule of MESA is planned to be integrated into the BERLinPro ring in order to perform high current beam tests. This unique opportunity is beneficial for both projects. Nevertheless, there are some challenges coming with the integration of the modules at Berlin. We will give an overview of the planned experiments and will report in particular on the adaption of SRF and cryosystems. Despite the diverse goals, the main linac, providing the larger part of the particles energy, is fairly compatible. It is planned to test and run the MESA linac module in BERLinPro, prior to its usage in MESA. The goals and benefits of this unique cooperation for both projects are outlined in this paper. The necessary adaptions in BERLinPro, including hardware aspects, the new optics, and the scope of performance are outlined in the paper.
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.
KPH, Mainz, Germany
MESA is a two pass energy recovery linac (ERL) currently under construction at the Johannes Gutenberg-University in Mainz. MESA uses two 1.3 GHz TESLA type cavities with 12.5 MV/m of accelerating gradient in a modified ELBE type cryomodule in c.w. operation. One potential limit to maximum beam current in ERLs is the transverse beam breakup (BBU) instability induced by dipole HOMs. These modes can be excited by bunches passing through the cavities off axis. Following bunches are then deflected by the HOMs, which results in even larger offsets for recirculated bunches. This feedback can even lead to beam loss. To measure the quality factors and frequencies for the dressed as well as undressed cavities improves the validity of any current limit estimation done.