Session 2 – HV cables, connectors and feedthroughs

1. Session 2 – HV cables, connectors and feedthroughs TCM https://indico.cern.ch/event/682148/sessions/266976/#20180312 Presentation 1: Cables and Terminations for Pulsed Power (Chris Jensen) This presentation gives an overview of his experience of high voltage cables construction, partial discharge and termination methods. Highlights include his advice to avoid insulated wire in order to remove the risk of trapped air breaking down, and to add choke cores around earth connections to provide a higher impedance for currents flowing in ground loops. He discusses the advantages of commercial versus custom designed terminations; recommending bolting, soldering or welding were possible, or contact bands from Multi-Contact but avoid those designed for EMI applications. Presentation 2: Overview of HV Cables and Connectors, Cable Procurement and Future Activities (Thomas Kramer) Thomas’ presentation explains the requirements for high voltage cable at CERN for both energy storage and transmission. The benefit and disadvantages of various types of coaxial cable are demonstrated. Of particular note is the increased losses when a semiconducting layer is included, and the difficultly in supporting operations of a SF-6 system and the availability of a replacement cable. Cables referred to as RG-220 (often wrongly due to the modern variants) are used extensively at CERN with various types of connectors; including commercially available LEMO as well as in-house designs.

2. Session 7 on Kicker Systems and Magnets Materials https://indico.cern.ch/event/682148/sessions/266993/#20180313 TCM

3. Session 7 on Kicker Systems and Magnets Materials TCM The first contribution was given by Patrick Alexandre from SOLEIL. He reported on the Non-Linear-Kicker designed by SOLEIL and MAX-IV and recently installed at MAX-IV. The NLK should substitute the usual 4 kickers arrangement used at present to inject into most of the light sources. The main advantage is that by design it does not affect the stored beam, making injection fully transparent.

4. Session 7 on Kicker Systems and Magnets Materials Extraction TCM Sebastian Heberer from GSI presented the status of the injection and extraction Kickers for the FAIR SIS-100 machine. For the injection kicker (rise time 130 ns, 70 kV, 6kA) the design is completed and the manufacturing is ongoing. The extraction kicker which will also be used to dump the beam in case of emergency is still under design. Critical for this system is the accuracy required on the HVPS (<1·10-4) and the emergency detection.

5. Session 7 on Kicker Systems and Magnets Materials TCM The third contribution, given by Christopher Jensen, from Fermilab, presented a nicely structured review of different magnetic materials to be used in the construction of kicker systems. Chris provided a useful list of considerations to take into account before choosing the right material and a worldwide overview of companies dealing with ferrites. A brief introduction into measurements of materials and details for two interesting examples were given.

6. Session 7 on Kicker Systems and Magnets Materials TCM The final contribution was presented by Luis Miguel Coralejo Feliciano on the experience and procurement of ferrites and alternative materials. The CERN experience is that ferrites procurement for specific purposes has become difficult mainly due to the small capacity production of the few companies capable of producing ferrites for particle accelerators. To address this point two approaches are being followed: CERN will conduct a market survey outside Europe in the near future and in parallel try to find alternative materials.