TIARA PP TIARA Final Meeting 27 th November 2013 – Daresbury

TIARA PP TIARA Final Meeting 27th November 2013 – Daresbury TIARA-PP WP 9 : TIHPAC Test Infrastructure for High Power Accelerator Components • Sébastien Bousson • (CNRS/IN2P3/IPN Orsay) • On behalf of the WP9 participants: CERN, IPNO, ESS

A little reminder : WP 9 Main Goal WP9 raised from the following consideration: What would be the necessary test infrastructures for developing the key elements of the EURISOL project ? EURISOL is the next generation of a facility aiming at the production of radioactive ion beams (RIB) using the ISOL technique. Among all the technical challenges raised by this project, 2 key components have been identified which will require an important R&D program and an intense experimental program to design these components for the Eurisol requirements: • The multi-MW target complex • The low beta superconducting cavities (used for the driver and for the post-accelerator linac)

Sub-Task 1: Multi MW target development

Sub-Task 1: Multi MW irradiation facility The main idea of sub-task 1: • Develop a versatile Multi MW Irradiation Facility for complex target testing to be tested with beams at all possible locations, meaning over a wide range of beam power (several kW to MW). • Full scale test of the final MMW target available only in the final facility ! • Achieving the design of the full scale target (ex. 4 MW for Eurisol) will require several partial tests: sub-components, irradiation at lower power, material testing, specific instrumentation developments… • For that, an irradiation facility for complex target testing is required, hosting an adaptable target in order to test concepts, instrumentation, material science (like fatigue, heat transfer), safety (primary/secondary fluid interactions), etc… The target itself should be adaptable, but keeping all services (heat exchanger, loop…) externalized (i.e. common for all target geometries).

Sub-Task 1: Multi MW irradiation facility Break-down of items/systems to be tested: K. Samec

Sub-Task 1: Multi MW irradiation facility The details of the huge design work of this facility achieved by the CERN teams have been presented yesterday in Yoann Fusco’s talk

Sub-Task 2: low beta cavity test cryomodule

Such a cryostat, specific and devoted to low beta SC cavities will be a useful complementary equipment. Sub-Task 2: low beta cavity test cryostat Before assessing that a SC cavity is validated for an operational use in an accelerator, the final experiment is a cryogenic test at nominal RF power of the fully equipped cavity (power couplers, cold tuning systems…) Very few “accelerator configuration” test cryostat are existing in Europe and they are only designed for elliptical cavity testing (CHECHIA , HOBYCAT, CRYHOLAB).

Sub-Task 2: low beta cavity test cryostat User requirements have been collected to establish specifications for this versatile low beta cavity test cryostat. Identification of the user requirementsfor the test cryostat: 4 main categories of requirements have been identified: Geometric dimension (cavity type and physical capacity) Integration of couplers and cold tuning system Cryogenic requirements Assembly requirements • EU Project driven requirements: • EURISOL, MYRRHA, ESS, IFMIF, HIE-ISOLDE • With potential interest for: • LRF (HUELVA), ion or RIB post-accelerators,… • … and many others outside Europe !

Sub-Task 2: low beta cavity test cryostat • Different cavity geometries (type), beta, and frequencies • Half-wave resonators • Quarter wave resonators • Spoke cavities (single, double or triple spoke) • Others: re-entrant, CH,… • Integration of the possibility to mount a superconducting magnet for residual magnetic field test or potential pollution during assembly • Vertical or horizontal positioning to be envisaged for some cavities QWR Double spoke Triple spoke QWR HWR HWR Single spoke

Sub-Task 2: low beta cavity test cryostat • Integration of couplers and cold tuning system • Integrating couplers and tuners for different geometries is the main concern for this versatile cryostat • Power couplers: For all cavity type, geometries are very different: the cryostat should have the possibility to have couplers located on the the bottom or on the side of the module (on top: option discarded). • Cold tuning system: Also very different from one to each other: tuning by deformation, volume insertion, integration of piezo actuators; using cold or warm motors . • Only a cryostat with high flexibility (many openings & access) can solve this issue.

Sub-Task 2: low beta cavity test cryostat • Cryogenic specification • Operating temperature: 4.2 K or depressed He bath (2 K typically) • Power: the cryogenic system should be able to handle about 80 watts (in average) of dissipated power at 2 K • Cooling time: in order to avoid the ”100 K effect”, the module should be able to cool down rapidly (typically, not more than one hour between 130 K and 70 K) • Assembly requirements • The cryostat assembly has to be feasible in a huge variety of clean rooms : height requirements not too important, as simplest as possible assembly tooling, lowest possible amount of material entering in the clean room (pollution control) => concerns with the clean air blowing direction • No requirements on any alignment device (has only meaning in a real accelerator module)

Sub-Task 2: low beta cavity test cryostat • Preparation and assembly fundamentals • The volume constituted by the cavity and its power coupler has to be prepared in dust free conditions. The cavity and its power coupler, up to the coupler window, are assembled inside an iso4 clean room. • The cavity volume is then evacuated to secondary vacuum, inside the clean room, and closed with an insulation valve able to be cooled down at cryogenic temperature (typically full metallic UHV valve). • The cavity and its couplers are then inserted inside the cryostat outside the clean room.

Sub-Task 2: low beta cavity test cryostat Preparation and assembly fundamentals Two different cryostat configurations have been envisaged • Option #1: Insertion along the Horizontal axis on a cylindrical Cryostat • Option #2 : Insertion from the top on a rectangular Cryostat

Sub-Task 2: low beta cavity test cryostat Vacuum vessel design • 1/ Rectangular section • 10 mm thickness not enough (buckling) Displacement Stress

Sub-Task 2: low beta cavity test cryostat Vacuum vessel design • 2/ With arc of a circle • 10 mm thickness Displacement Stress

Sub-Task 2: low beta cavity test cryostat Vacuum vessel design • 3/ Polygonal shape • several geometries studied

Sub-Task 2: low beta cavity test cryostat Vacuum vessel design: polygonal shape is the final choice Even with this shape, stiffeners are still required, but of a simple shape, much easier than the one required for a rectangular shape.

Sub-Task 2: low beta cavity test cryostat Cryostat main components

Sub-Task 2: low beta cavity test cryostat Integration of the cavity string 1 - The cavity string coming from clean room is fixed to the special frame of the Cryostat top cover. A crane and a simple supporting frame is required for handling the different parts. Partial cryogenic tubing is then assembled. Instrumentations of the cavity string and assembly of the cold tuning system may be performed at this stage. 2 - The thermal shield is assembled as well as the remaining instrumentations or cryogenic tubing. The component at this stage composes the Cryostat cold mass. 3 - The Cold mass is inserted inside the Cryostat vacuum vessel from the top (with a crane) 4 - The Cryostat vacuum vessel exhibits large openings, on the top and the bottom as well as on the sides to allow access and assembly of the various geometry of auxiliary components. It is possible to assemble cavities with horizontal (on the side) or vertical (bottom/top) Power Couplers. The assembly of all the remaining auxiliary components or instrumentation are done at this stage.

Sub-Task 2: low beta cavity test cryostat View of the cryostat integrating a spoke cavity

Sub-Task 2: low beta cavity test cryostat View of the cryostat integrating a quarter-wave resonator

Sub-Task 2: low beta cavity test cryostat View of the cryostat integrating a half-wave resonator (horizontal)

Sub-Task 2: low beta cavity test cryostat Cryostat final dimensions

Sub-Task 2: low beta cavity test cryostat • Conceptual study of the valve box: • The conceptual work is done (the detailed design is not integrated in the Tiara work list) • Only missing point is the specific cooling line for the SC magnet • At this stage, no specific requirements will be integrated (like magnetic shielding pre-cooling for instance), but the valve box will be compatible with the integration of such specific cooling lines. • Interface with the cryostat is from the to; then the cold box could be located either on the side or on the top of the cryostat.

Sub-Task 2: low beta cavity test cryostat Concept of the valve box for the cryostat

WP 9 Work Status: Gantt chart

WP 9 Work Status: task completion

WP 9 : Deliverables • WP9 Deliverables consists in 2 engineering report describing the detailed designs of the two equipments • In both cases, the design work is almost achieved, but the reports have to be completed for the (nominal) end of Tiara-PP !

Conclusions • An important design work was completed in Tiara-PP on two testing facilities: • a Multi MW Irradiation Facility for complex target testing • a versatile cryostat for fully-equipped low beta SC cavities • Even if the need of such equipments was raised by Eurisol, many other projects, in EU or worldwide, would benefit from the existence of such facilities. • A cost estimate for each equipment will be done and indicated in the final report, but the order of magnitude is about 1 M€ for each

Thanks to all the contributors to the TIARA WP9: Teams from CERN, IPNO and ESS

Long Live TIARA !

TIARA PP TIARA Final Meeting 27 th November 2013 – Daresbury