Project Description
PROJECT DESCRIPTION, OBJECTIVE, AND SCOPE
The LCLS II Project at JLab is funded to lessen the testing backlog at the CryoModule Test Facility (CMTF) in the Test Lab. Two LCLS-II style cryomodules (CM) will be tested at a time in the LERF vault. This will be on a ~2 month cycle and will repeat up to 4 times, testing a total of 8 CMs. Two CEBAF style CMs will be removed from the vault to be available for the CEBAF machine. The third CM will be relocated from the third position to the FL02 position and be reconnected. This CM will act as a LHe buffer tank and also be used for a series of Q0 studies over the next year. There is intension of running electron beam in the vault for the isotope program during of this project. The project is expected to last ~18 months, then the LERF will be restored to an operational state (as it was before this project).
The scope is to install 16 Solid State Amplifiers (SSAs), & Low Level RF (LLRF) in LERF gallery. These SSAs, which are on loan from SLAC, will be connected to the existing waveguide that routes to tunnel. The klystrons and circulator will be removed and stored to make room the waveguide modifications. Additional waveguide will be purchased to accommodate the SSA connections and the CM connections in the tunnel. The waveguide will be pressurized and interlocked to the PSS, as is the existing system. New cables will be installed for the instrumentation and tuners in the existing penetrations (these are not filled with gravel like CEBAF penetrations). The existing cable trays will be used, a few cross-overs will be added.
The AC power will be removed from two Cathode Power Supplies (CPSs) and re-routed to two new 480VAC/400Amp service panels to be located in front of the CPSs. These will duplicate the installation of the AC distribution/PSS from Test Lab facility.
A new cryogenic ‘end can’ and transfer line will be designed, and procured to enable connection for both 2K and 40K shield circuits, supply & return. This transfer line will be designed to use the existing U-Tubes. Since the LCLS-II CMs have the cryogenic connections on the same end of the CM it will connect to the supply of the Zone 2 CM and the return of the Zone 3 CM. The quad girders will be removed from this area to enable ease of access for the U-Tube stabling operation.
The CMs will be transported by flat bed to the LERF parking lot for staging. When starting a new test cycle, the completed CMs in the LERF vault will be disconnected from each other, and from the cryogenic end can, this operation is done with portable clean hoods.
The project will require the installation and commissioning 16 sets of LCLS-II LLRF hardware & software. Most all of this will be EPICS based and provided by SLAC. A new managed Ethernet switch and terminal server will be purchased. This will allow for easier control of remote access from collaborators at SLAC & Berkeley. A dedicated server will also be purchased, SLAC is using EPICS 3.15 version where JLab is using 3.14. The dedicated server will ease any compatibility issues. The CM testing & commissioning tools will be jointly developed. It is envisioned that there will be frequent and extended visits from SLAC personnel to aid in the installation and commissioning of the LCLS-II based cryo, vacuum & interlock systems. The JLab computer center is being consulted on remote access and cyber security aspect of the project.
The baseline is to install and remove the 27 concrete shield blocks for each testing cycle. Restore LERF once CM commissioning is complete at the end of the ~18 month project.