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CRYO aspects of the test bench modifications in SM18
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Europe/Zurich
Description
https://vidyoportal.cern.ch/join/i1QDk8pqbWPr
Marta presented the first draft of the technical specification for the cluster F/A for magnet testing, in particular Q2a and Q2b. For this document, Herve Prin will be the technical contact regarding the cold mass (routing of the bus bars and connections, including electrical and cryogenics), Susana Izquierdo for the magnet specifications and requirements for the test ( current, time of test) and Delio Duarte regarding the cryostating. Robin Betemps, Philip Perret and Romain for the design of the potential modifications in the magnet and, to be reviewed, modifications in the CFB.
This first draft is following a template that Gabriella prepared for the IT string, in terms of structure and topics of the chapters.
This document strictly contains information linked to the magnet to be tested and what we want to test. After the review of the document and the acceptance by CRG, the CFB will be modified accordingly.
The very first part is the standard page showing meta info about preparation, checks and approval.
Coming to the specific parts of the document:
- Scope:
- Introduction The functionalities required of the test bench for the Q2 cold masses
- HL-LHC Q2a cold masses: Description of the magnet showing type of superconductor(s), parts of the cryo-assembly including correctors that justify several circuits to be powered.
- HL LHC Q2a cold mass in the test bench. Test bench to be used and first requirements of the magnet test: Temperature of the test, maximum gradient allowed (sensor and position to be defined), need of an anti-cryostat, thermal cycles required.
- Design inputs for the functionalities required of the test bench for the Q2 cold masses
- Schedule of the master plan and phases of the magnet test that have to be respected.
- Current design of the cold mass
- Current design of the existing infrastructure, with the aim of re using as much as possible the current equipment, including:
- Test benches
- Cryogenic infrastructure
- Handling equipment
- Thermo hydraulic requirements: To be completed with the process functional diagram and with input from CRG. Yacine will work on this aiming for a similar output as the PFD for D2 by Arnoud Vande Craen.
- Electrical requirements: Circuits to be powered (including protection), connection and splices, powering specifications (current, dI/t, time of test, time of recovery). The duration of the test is divided into different phases which foresee different requirements for the test (quench, steady state, cooldown, warm up…).
A chapter about scheduling will be added.
To review contents please refer to the document.
Salvador Ferradas presented the current status of test bench F2. The presentation is divided in three main aspects:
- Powering,
- Cryo
- Equipment to be tested.
A list of actions regarding control will be implemented.
Inside powering there are several circuit ratings.
20 kA circuit: The installation of the new load switch is something rather quick and that is going to be done as soon as possible after the restart. The load switch implies the reconnection of the WCC but for F2 a new complete redesign of the routing is needed.
The cabling of F2 is a big chunk of work. From recent conversations with Samer (EPC) the power converters and cabinets going to stay 99% sure in the location showed in the latest integration study from Antoine. This means that once the position of the DFH is fixed, a new iteration of the integration study can be done including the routing of the cable. The positioning of the DFH, according to Paul Cruikshank, is something that Antoine can tune to his needs.
Taking in account that there are no CDBs foreseen and the flag of the current lead is not designed to accommodate WCC cables, MSC-SCD will provide a flexible copper interface. The design is to be launched, coordinated by R. Betemps.
Regarding the 2 kA circuit, the power converter is a deliverable by EPC scheduled for September this year (dates before COVID). Again, the positioning of the 2 kA will be where the current integration shows. Therefore a next iteration of the integration including the routing of the cables can be started.
Regarding the 7 kA circuit, the required tests should be defined. The rating of the Sc cable inside the link is 7 kA, however the rating of the current leads is 2 kA for nominal operating conditions and 7 kA during maximum 1 min (the Cu part was not designed to withstand for more than a few seconds before a thermal runaway occurs). The nominal current that is going to flow through this circuit is 2 kA and the peak current expected is 6.8 kA for 0.1 to 0.2 seconds. Probably the limitation is given by the ramp rate available of the power converter The test that the 7 kA circuit has to undergo will notably affect the design of the warm part of the circuit.
After that, the decision to be taken is which power converter will be used.
For every powering circuit, EN will validate and perform the installation. The schedule of the actions that are going to be performed
With respect to the cryo, there are no modifications foreseen in the CFB. TE-MSC-SCD will provide soon the design of what is going to be permanently connected to the CFB. A kind of DF module along with a jumper interface will act as an extension of the CFB, common for every SC link test.
In addition to that, a small procedure or list of actions to be carried out between SC Link tests will be given to TF. It is worth to remark, that there are no works foreseen in the connection to the CFB between tests. Every action will take place in the DF side. Nevertheless, it has to be confirmed if at least one nominal DFX is going to be tested at cold and in which conditions (powering included or not… etc)
Control: The person in charge is Marylin C., she provided an extensive list of tasks to be performed including estimated duration. We will meet on Friday to better put them together in timeline and if there is any help I can provide with linking inputs she might need the better.
The schedule of arrivals of equipment to be tested is given by MSC-SCD and it is based in a pre-covid situation. Please refer to the slide for a clear understanding.
Finally, Antonio Perin presents the current TE-CRG master schedule for the IT String proximity cryogenic equipment (PCDS) and cryoline (SQXL); the ScLink test on F2 and the CLs test bench on cluster G feedbox. If there was to be any modification of the CFB, it should be included in the masterplan.
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