[pulser]

Mask off parts you don’t want coated. Polyamide tape should be good.
Etch with peroxide. This assumes a good solvent clean before taping.
Sputter etch or ion mill the tungsten oxide off and deposit your favorite metal, iridium, platinum, palladium, copper using sputtering insitu. Tungsten forms an oxide readily with exposure to air.
Remove the masking tape. Now your part has a low resistance contact.
Tungsten sucks for low ohmic contacts. We use tungsten probes to aluminium and with scrubbing typically a few ohms.

[pulser]

Do you think glass filled Torlon would work? Much more shock proof.
http://www.boedeker.com/torlon-5530.htm

[pulser]

http://www.quartz.saint-gobain.com/MICAVER®.aspx

This looks like an interesting material for this application.

Sounds like a polyimide or other non-outgassing polymerizable organic and ceramic composite could be a good choice giving stiffness and robustness against shock.
The part could be coated by SiO2, AlN, etc. by sputtering or other deposition technique if no organic exposure is allowable.

[pulser]

I just ordered Kapton film from ColePalmer last week to stand off a silicon wafer from a chuck (My arena is 30A, 1KV, 5ns pulses with 200ps rise times – different than DPF – but all fun to work with).

If one wants to use Kapton but is concerned about surface damage, then coat with a layer of SiO2, Al2O3, AlN, or Si3N3 by sputter or PECVD deposition.
Multiple layers of insulators interspersed with conductive layes can withstand higher fields).

Saphire can be purchased in wafer form, not sure what diameter is needed here. Much stronger than quartz or glass.
Gorilla glass (Corning) has substantial strength and resistance to damage. If a sheet can be used, this could be useful.

If you can forward me mechanical diagrams, pictures,engineering objectives/constraints, etc., I could make better recommendations.

[pulser]

Here is a good reference: http://www.vacuumlab.com/Articles/Gas Loads and O-Rings.pdf

Also get a good book on vacuum technology: http://www.amazon.com/Users-Guide-Vacuum-Technology/dp/0471270520
and this is a must have:
http://www.amazon.com/Building-Scientific-Apparatus-John-Moore/dp/0521878586/ref=pd_sim_b_1

Still happy to provide guidance. 🙂

[pulser]

Here is a starting point. http://www.lesker.com/newweb/index.cfm
They should be able to help with your vacuum needs.

[pulser]

Can you provide existing cross sections and diagrams of what you would like to change?
There are may trade-offs possible so more info is helpful.

[pulser]

For a fast clean of the window, make a clip which will hold a saphire (or glass) plate in front of your existing window. Clean the Cu with HCl (obtained at Safeway to adjust pool pH). Rinse in water for 5 minutes. Put back. All done in 10 minutes and can be done in a fumehood with no exposure to fumes. Don’t care about the stainless since you remove the plate from the system or cleaning.

[pulser]

Start here –> http://en.wikipedia.org/wiki/Parts_cleaning
Plasma based cleaning is fine for removing sub-micron layers, but not bulk contamination.

Cu etching–>
http://www.transene.com/cu_etchant.html

Put in a rotatable transparent shutter to extend time to cleaning.
Use a removable piece of glass/quartz/saphire in front of the window and clean this.

[pulser]

JMP 9(by SAS) is a commercial data analysis package. I use it daily and it is good for DOE design, DOE analysis, multi-variate linear and non-linear modeling and much more. At least with so many users and more than 15 years in the field many resources have been put behind it to assure validity and functionality and they are always adding more capabilities. Works on a PC, Mac, or Linux.

[pulser]

Kapton is good for vacuum systems, but as mentioned will break down over time. Use 4x the thickness associated with dielectric strength for long term reliability.
Dealing with high voltages can be challenging. Use of semi-insulators will help with limiting electrostatic charge build-up and localized breakdown. I’ve found most people are not familiar with semi-insulators and the concept of what they do and how to use them is challenging even for electrical engineers working with high voltage devices for a living. Semi-insulators include materials like SIPOS and silicon rich silicon nitride (more like amorphous silicon than Si3N4). Carbon could also be used but I have no experience on the best form or deposition methods. Sheet resistances of 1e12 to 1e15ohms/sq are typical. Using alternating layers of semi-insulators and high dielectric strength insulators is a very good way to stand off very high fields even with ionization taking place creating localized high field spots. For pulsed applications such as this, much higher conductivity films could be utilized as long as the power dissipation does not cause significant self heating.

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