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1 Free Call: l

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3 MKS Pressure Measurement Indirect Gauges Gauges for High Energy Physics Applications

4 NSLS-II Brookhaven, USA Diamond Light Source, UK ALBA Synchrotron, Spain PAL XFEL, South Korea

5 Typical Gauge Requirements and Environment Measurement range: Atmosphere to < 1x10-11 Torr Convection Enhanced Pirani for Atmosphere to 10-3 Torr Ionization gauge for UHV measurement, Cold cathode Inverted Magnetron or hot cathode gauge Need for set point relays to control i.e. RGA, valve operation, ion pumps Operation up to rad, (10 5 Gray) over ten years Sensors need to be bakeable and able to operate during bake-out Digital communications required- RS232, 485, Profibus Fast response relay for system protection

6 Gauge System Components Multi Gauge Controller Convection Enhanced Pirani Inverted Magnetron Cold Cathode Cabling

7 Series 937B Controller Preferred Controller for High Energy Physics Applications Display up to 6 sensors simultaneously Ease of operation 12 set points standard, 2 per channel/ 4 per slot Fast response analog output (15 msec) Fast relay Response TTL (15 msec) Non-Radiation Hard Designed for CSA compliance

8 Series 317 Convection-Enhanced Pirani Sensor Aluminum housing design for Synchrotron Applications Atmosphere to 10-3 Torr Convection-enhancement improves near-atmospheric measurement Quick and easy to remove electronics Bakeable to 250 C with electronics removed Entire assembly radiation resistant CE Compliant

9 Series 422 Cold Cathode Subsets Originals 421 Sensor Developed in Mid 1980 s Teflon insulated connectors Original cable material radiation resistant 250 C bakeout with connectors removed Series 422 Introduced in the Mid 1990 s Connectors changed to BNC/SHV and Teflon was removed Radiation resistant 250 C bakeout with connectors removed Series 422 Upgraded in early 2000 s Uses LEMO radiation-resistant connectors, with PEEK insulating material Operation temperature increased to 250 C Field Emitter option added for decreased starting times

10 Series 422 Cold Cathode Ionization Gauge HEP Enhanced version of the existing Series 421 sensor Measurement to 1x10-11 Torr Designed for both high temperature and radiation resistance Sensor can operate during bake-out (250 C) Separate ion current and high voltage connector (increases accuracy of pressure measurement, no need for Triax connectors/ cables) Uses LEMO radiation-resistant connectors Bakeable and/or radiation-resistant cables available CE Compliant

11 Cabling Considerations Facilities often have their own requirements for cables, such as fire resistance, flame rating. Low Smoke, Zero Halogen requirement has become very common. Many installations make their own cables, terminating them after the basic cable material is pulled through a cable tray. Consult cable stock manufacturers for specific concerns, such as cables that will handle the low current signals found with ionization gauges. Question whether it could be advantageous to use different cable types in the connection of a sensor to the controller. This will often mean the use of some sort of junction box. Test loads for gauge simulation & cable verification

12 MKS Cable Offerings Cable stock and connector sets Intermediate Cables high temperature and radiation resistant Custom length complete cables Standard Cables

13 Considerations in the Selection of Cable Material Bakeout temperature Radiation levels Ease of finding mating connectors Material Name Application PEEK Polyether ether ketone Radiation and Heat Polyethylene Polyethelyne Radiation, but not Heat PTFE (Teflon) Polytetrafluoroethylene Heat, but not Radiation Kapton Polyimide Radiation and heat, high cost

14 High Energy Physics Gauges The Vacuum Gauging System: Convection-enhanced Pirani Series 317 Series 422 Cold Cathode Ionization Gauge Multi-gauge Controller, Series 937B Sensor Connector Sets Cable Selection High temperature CCG operation Sensors designed for use in a radiation environment Up to 12 set point relays for control/ indication/ alarm Fast response outputs for system protection

15 MKS HEP Gauging Locations Cornell Daresbury Diamond Ganil Spiral-II Soleil SSRF PAL CLS RRCAT SLAC BNL RHIC NSLS-II NSRRC ORNL SNS ALBA Australian Synchrotron Locations with large number of 937 controllers and sensor.