Work Package 2: Coordination Meeting #9

Wednesday 16 Sept 2026, 00:00 → 02:00 Europe/Zurich

Sept_2026_Granados_lasers.pdf

Test Stands at CERN

CERN is upgrading the CTF3 facility to establish an RF test stand for high-power testing of RF structures and, at a later stage, of the complete RF module foreseen for the FCC-ee injector. The facility is also planned to host the FCC-ee electron source (including one or two RF modules), with beam commissioning activities targeted from 2030.

 

CTF2

Adjacent to CTF3, space is available for the installation of a photocathode RF gun, which may already be in place. Originally developed for the AWAKE project, the gun does not include a load-lock system, has a potentially limited charge capability, and operates at a repetition rate of 10 Hz. An alternative option under consideration is the installation of the PHIN gun together with a load-lock system; however, no decision has yet been made and the implementation schedule remains to be defined.

 

Generation of a Four-Bunch Train

The generation of four bunches from a single laser system is being discussed based on concepts proposed by Eduardo. A key outcome of today’s discussion was the need for dedicated simulations to refine the specifications, particularly in light of the planned inclusion of a damping ring for electrons. In addition, the parameters of the modulated bunch train must satisfy the requirements of the positron source. These studies will be carried out by Zdenek using the PSI test beamline.

 

From the CHART project:

The development of photocathodes for the injector presents a significant challenge, requiring a balance between high charge extraction and long operational lifetime. This task will be conducted through a collaboration between PSI and CERN, leveraging their combined expertise to advance photocathode technology. The partnership will ensure that the latest innovations in material science, fabrication techniques, and operational strategies are integrated into the project. The primary goal is to produce high performance photocathodes suitable for testing at the PSI electron source test stand. The milestone for this task is the successful production of photocathodes ready for experimental validation at PSI. With a view on strengthening the collaboration between PSI and CERN in photocathode R&D and proving the capability of exchanging high quantum efficiency photocathodes reliably, CERN proposes the design and construction of a vacuum system that allows for the exchange of photocathodes using the existing production and testing infrastructure at both facilities. The work foresees the delivery and characterization of photocathodes grown at CERN at the PSI laboratories using the designed system. The main objectives are to build up compatibility between photoemission (PE) lab setup at CERN and at PSI; reliable production and development of Cs2Te photocathodes in the PE lab at CERN; transport and testing of photocathodes in the RF gun at PSI.

 

ACTION: Ralf will provide a cost estimate for this activity. 

 

Fair comparison of electron source:

It is not clear what the new phase space acceptance is for the damping ring and the requirements for the final focus of the positron source. These numbers are critical to be able to evaluate whether an electron source is compaticle with the FCC injector requirements.

ACTION: Tom to ask Simona about acceptance.