1. Philtec Positioning Device D63 SENSORS

2. DC Spark System D63 Sensor Context: – Philtec was contacted to ask for the possibility of installing a new positioning device for the gap – Questions back and forth This is the outcome of such exchange of information

3. DC Spark System D63 Sensor For system I: best use a reflectance dependent sensor D63 (implied as well for system II) – Output is proportional to distance from target as well as reflectivity of the material Main problem: perpendicularity!! – Probes must within ±0.5⁰ of perpendicularity

4. DC Spark System D63 Sensor Roughness of the sample: – 50-100nm  Ok – Calibration stored is for anodized Al. Send sample for calibration if needed/wanted

5. DC Spark System D63 Sensor Gap measurement: – Manual alignment possible – From 20μm to 50μm – Near side response will give best results. Perpendicularity!!

6. DC Spark System D63 Sensor Probes: – Materials: Borosilicate glass, low outgasing epoxy and SS construction. – Cable sheathing (under UHV conditions): Teflon: bend. r=75mm, or SS interlock: bend. r=19mm – Max. temperature of operation: 480⁰C – Dimensions: Tip Ø outer = 3.18mm Fiber optic Ø outer = 1.6mm

7. DC Spark System D63 Sensor Flanges: – Bv2 CF: 2 sapphire windows Bakeable to 450⁰C without cables Accepts one D model sensor

8. DC Spark System D63 Sensor Possible solution to overcome the perpendicularity issue: Jacket to hold the ceramic parts and the probes Sample’s surface Gap measurement Ceramic holders (spring) Probes Tip/Anode Zero Position

9. DC Spark System D63 Sensor Some questions: – Because of dimensions: two rows of spots still possible? – Reflectivity of ceramic part? If <10% then contact Philtec, or make coating? – One flange per channel, and we want at least 2  enough flanges?