LISAH

LISAH

The Accelerator and Hyperfrequency Systems Engineering Laboratory represents DACM’s expertise in the design and construction of high frequency electromagnetic structures and their implementation through the use of appropriate instrumentation. At the end of 2015, laboratory staff consisted of 18 engineers and five technicians.

Laboratory activities involve mainly the development of radiofrequency structures for particle accelerators used in physics research (radiofrequency quadrupoles, superconducting cavities, power couplers with highorder harmonics suppression), as well as the associated qualification tools, including RF power sources and instrumentation. The laboratory also manages certain shared DACM resources, such as SupraTech-CryoHF RF test platforms and the new 352 MHz platform. These activities also cover applications in other fields such as antennas for high-field magnetic resonance imaging.

In carrying out its work, LISAH has access to internal expertise within IRFU in the fields of material sciences, process engineering, mechanical construction, and quality assurance. The laboratory also contributes to other IRFU projects, either by taking charge of an entire work package or by providing technical consultancy services.

#3355 - Last update : 07/05 2023

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352 MHz RF Platform : Context High power tests of RF accelerator components (power couplers, RFQ, warm cavities) can be performed for structures resonating at 352 MHz. The platform is equipped with two CW klystrons and one pulsed klystron. RF signal can be sent to three radiation shielded bunkers.

352 MHz RF platform : 352 MHz RF platform is equipped with: ? Two Thales TH2089B klystrons that can each deliver 1.3 MW of continuous RF power. ? One Thales TH2179A pulsed klystron with an in-built DTI Sigmaphi modulator with a peak power of 3 MW, which can deliver 240 kW of average RF power, with a pulse length of between 10 and 3600 μs and a frequency repetition of between 1 and 50 Hz. In particular these characteristics cover the useful cycle of the ESS (European Spallation Source).

Cryholab – laboratory horizontal cryostat (property of IRFU-IN2P3 ) : Tests of superconducting cavities in the same conditions as in an accelerator. Radio frequency power supply: now 700 W; foreseen: 80 kW for continuous input; up to 1 MW for pulsed input. Pumping unit coupled with Helial 4012 refrigerator: 80 W at 1.8 K and 13 mbar. Useful internal size: 1.5 m length and 70 cm diameter.

Cryo/HF Supratech platform : The Cryo/HF Supratech station has cryogenic and hyper-frequency equipments[PO1] that can be used to develop the key subassemblies of superconducting accelerators such as superconducting cavities, power couplers and complete accelerator modules (e.g. cryomodules). In the last three years, it has been used to test the 12 cavities and 12 cryomodules for SPIRAL2, the HIPPI power couplers (for the European EuCARD program and in collaboration with CERN) and the prototype cavities for the IFMIF and ESS projects.

Diagnostics, vacuum and assembly laboratory (DIVA) : The laboratory is responsible for vacuum measurement, for research into the desorption of materials and the development of ultra-high vacuum techniques (assemblies and tests). Its equipment includes: ? An ultra-high vacuum oven that can reach temperatures up to 1200 °C at 10-6 Pa, with temperature uniformity at 900°C of ± 3°C. ? A desorption measurement bench for qualifying materials and developing cleaning procedures necessary for ultra-high vacuums.

Hélial 4012 Liquefier-Cooler connected to Supratech station : Liquefier production is around 170 or 70 litre/hour with or without nitrogen pre-cooling. A helium compressor 80g/s (1600 m3/h) and an Air Liquide cold box make up the liquefier. Its cooling power is around 80 Watt at 1.8 K

Horizontal cryostat for cavity tests : Context High power RF characterization tests of superconducting cavities equipped with their power coupler and tuning system, at low temperature down to 1.8 K, in conditions close to their final use in an accelerator. A cylindrical horizontal cryostat (CRYHOLAB) shielded against earth magnetic field allows one to fully characterize superconducting cavities feeded with high power RF (thermal budget, Lorentz force detuning, microphonics, etc). Its dimensions are l = 1.5 m long and Φ = 0.

ISO4 clean room : Context Assembly of cavities following high pressure rinsing. Positive pressure clean room partitioned into 3 different ISO classes: 7, 5 and 4.

ISO5 clean room : Context Assembly of cavities following high pressure rinsing. Positive pressure clean room partitioned into 2 ISO classes (ISO class 7 and ISO class 5) and adjacent High Pressure Rinsing (HPR) room at ISO class 5.

Institute of research into the fundamental laws of the Universe

Fundamental Research Division