A New Cleanroom With Facilities for Cleaning and Assembly of Superconducting Cavities at Helmholtz-Institut Mainz

The Helmholtz-Institut Mainz HIM will operate a clean room facility for the assembly and possible re-treatment of superconducting cavities. This is mandatory for several SRF accelerator projects, like the advanced demonstrator for a dedicated sc heavy ion cw-linac at HIM or other projects pursued by research facilities or universities close by. While the installation of the clean room is in progress, the procurement of the appliances is ongoing. The present equipment planned and the current status of the installation will be presented

Further R&D For A New Superconducting Cw Heavy Ion Linac@GSI

A low energy beam line (1.4 MeV/u) behind the GSI High Charge State Injector (HLI) will provide cw-heavy ion beams with high beam intensity. It is foreseen to build a new cw-heavy ion LINAC for post acceleration up to 7.3 MeV/u. In preparation an advanced R&D program isdefined: The first LINAC section (financed by HIM andpartly by HGF-ARD-initiative) comprising a sc CH-cavity embedded by two sc solenoids will be tested in2014/15 as a demonstrator. After successful testing theconstruction of an advanced cryo module comprising fourCH cavities is foreseen. As an intermediate step towardsan entire cw-LINAC the use of a double of two CH-cavities is planned: A short 5 cell cavity should bemounted directly behind the demonstrator cavity inside ashort cryostat. The design of the cw LINAC based onshorter sc CH-cavities would minimize the overalltechnical risk and costs. Besides with this cavity anoptimized operation of the whole LINAC especially withrespect to beam quality could be achieved. Last but notleast the concept of continuous energy variation applyingphase variation between the two cavities with constantbeta profile could be tested

R&D Status of the New Superconducting CW Heavy Ion LINAC@GSI

To keep the ambitious Super Heavy Element (SHE) physics program at GSI competitive a superconducting (sc) continuous wave (cw) high intensity heavy ion LINAC is currently under progress as a multi-stage R&D program of GSI, HIM and IAP*. The baseline linac design consists of a high performance ion source, a new low energy beam transport line, an (cw) upgraded High Charge State Injector (HLI), and a matching line (1.4 MeV/u) which is followed by the new sc-DTL LINAC for post acceleration up to 7.3 MeV/u. In the present design the new cw-heavy ion LINAC comprises constant-beta sc Crossbar-H-mode (CH) cavities operated at 217 MHz. The advantages of the proposed beam dynamics concept applying a constant beta profile are easy manufacturing with minimized costs as well as a straightforward energy variation**. An important milestone will be the full performance test of the first CH cavity (Demonstrator), in a horizontal cryo module with beam. An advanced demonstrator setup comprising a string of cavities and focussing elements is proposed to build from 10 short CH-cavities with 8 gaps. The corresponding simulations and technical layout of the new cw heavy ion LINAC will be presented

Recent Status New Superconducting CW Heavy Ion LINAC@GSI

The demonstrator is a prototype of the first section of the proposed cw-LINAC@GSI, comprising a superconducting CH-cavity embedded by two superconducting solenoids. The sc CH-structure is the key component and offers a variety of research and development. The beam focusing solenoids provide maximum fields of 9.3 T at an overall length of 380 mm and a free beam aperture of 30 mm. The magnetic induction of the fringe is minimized to 50 mT at the inner NbTi-surface of the neighboring cavity. The fabrication of the key components is still in progress and is near to completion. After cold performance testing of the RF cavity, the helium jacket will be welded on. The cryostat is partly assembled and will be finished in the next weeks. The test environment is completely prepared. Advanced emittance measurement is foreseen to prepare for best matching of the heavy ion beam from the injector. Integration of the cryostat into the beam line, the first cool down of the module and commissioning of the RF elements will be performed as next steps towards a complete testing of the demonstrator

Beam dynamics for the sc cw heavy ion linac at GSI

For future experiments with heavy ions near the coulomb barrier within the SHE (super-heavy elements) research project a multi-stage R&D program of GSI, HIM and IAP is currently in progress. It aims at developing a superconducting (sc) continuous wave (cw) LINAC with multiple CH cavities as key components downstream the High Charge Injector (HLI) at GSI. The beam dynamics concept is based on EQUUS (equidistant multigap structure) constant-beta cavities. Advantages of its periodicity are a high simulation accuracy, easy manufacturing and tuning with minimized costs as well as a straightforward energy variation. The next milestone will be a full performance beam test of the first LINAC section, comprising two solenoids and a 15-gap CH cavity inside a cryostat (Demonstrator)