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Task 19 SIS100_3: Semiconductor RF Gap Switch

15.04.2005 P. Hülsmann

Problem DescriptionBeam dynamics simulations have shown that the impedance

of the non-operating cavities may degrade the quality of the circulating beam at high current operation significantly.

Solution Equip the gaps of the non operating cavities with fast high

power switches, generating a short circuit with low intrinsic impedance.

Technical Description

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Task 19 SIS100_3: Semiconductor RF Gap Switch

15.04.2005 P. Hülsmann

Requirements on the gap switch

Switch is open

Frequency

1 MHz

Voltage

25 kV

Duty Cycle

0,0005

Capacity

<100 pF

Switch is Closed

Current

60 A

Average Power

500 W

Duty cycle

3%

Resistance

< 10

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Task 19 SIS100_3: Semiconductor RF Gap Switch

15.04.2005 P. Hülsmann

First Tests with MosFet Gap Switch(Behlke HTS 301-12-AC-B + Cooling

Fins,Category VII) Breakdown at 12 kV RF-amplitude (1 MHz)

after 3 minutes (open) Due to dielectric losses, the isolation material

at the high voltage output has started to boil. The isolation was damaged, but not the semiconductors.

Average of 50 W reached (closed) A resistive resistance of 10 reached RF-characteristics of the switch ok

Next Step Isolation of the switch with oil

Status of R&D

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Task 19 SIS100_3: Semiconductor RF Gap Switch

15.04.2005 P. Hülsmann

Work Sharing GSI

Specification for manufacturing the switch Low-level testsPrototype cavity tests (0.8...5.4 MHz)

CERN Prototype cavity tests (2.8...10 MHz) Design of passive network for impedance reduction Shielding experiments for improvement of radiation

hardness Tentative schedule for 2005 available

Organizational Issues

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Task 19 SIS100_3: Semiconductor RF Gap Switch

15.04.2005 P. Hülsmann

Schedule (Description of Work)

Personnel not yet available → 5...6 months shifted

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Task 19 SIS100_3: Semiconductor RF Gap Switch

15.04.2005 P. Hülsmann

CostsTask 19: SIS100_3 (Fast Gap Switches)

2005 2006 2007 TotalScientists 0,4 0,3 0,3 1

33.600,00 € 25.200,00 € 25.200,00 € 84.000,00 €Technicians 0,3 0,3 0,3 0,9

25.200,00 € 25.200,00 € 25.200,00 € 75.600,00 €Investment 11.000,00 € 12.000,00 € 12.400,00 € 35.400,00 €

2005 2006 2007 TotalScientists 0 0 0 0

0,00 € 0,00 € 0,00 € 0,00 €Engineers 0,35 0,35 0,3 1

40.000,00 € 40.000,00 € 35.000,00 € 115.000,00 €Investment 10.000,00 € 20.000,00 € 20.000,00 € 50.000,00 €

Total 119.800,00 € 122.400,00 € 117.800,00 € 360.000,00 €

In 2005, a part of the GSI investment costs will be transferred from Task 18 to Task 19

GSI

CERN