Search found 165 matches

by Peter Schmelcher
Fri Oct 16, 2020 6:34 am
Forum: Images du Jour
Topic: Germanium Sputtering in the new Reserach Facility
Replies: 10
Views: 1318

Re: Germanium Sputtering in the new Reserach Facility

Nice setup. I attempted gate valve pressure control a few years back and moved on to mass flow controllers. In hindsight I think it was an area problem in that the gate valve position was almost fully closed for the pressure I wanted. The net result was a big pressure change with a very small mechan...
by Peter Schmelcher
Wed Jul 29, 2020 6:09 pm
Forum: Books & References
Topic: Books
Replies: 0
Views: 3987

Books

Two books that are worth a look: High Voltage Engineering Practice and Theory This is a text book circa 2000 130pages with graphs and pictures. I downloaded a draft version. Starts with a historical introduction and moves on to practical equations, tables, graphs etc. In an example problem calculus ...
by Peter Schmelcher
Tue Jul 28, 2020 7:49 pm
Forum: Images du Jour
Topic: Fusor Update - Liam David
Replies: 20
Views: 2682

Re: Fusor Update - Liam David

Nice work/report. Some thoughts on the connector. The commercial CA11 connector had vents and far fewer seals so you could nick the O-rings on the inside to create a vent but alternate the vent positions so they do not line up. If a flash over ever happens it should track and damage the surface of t...
by Peter Schmelcher
Sun Apr 12, 2020 1:57 am
Forum: Vacuum Technology (& FAQs)
Topic: First ever Turbo experience
Replies: 38
Views: 10033

Re: First ever Turbo experience

The little turbo pumps can be cycled fast back and forth to atmosphere quickly and you can even get them with aerodynamic breaking vents. When these are used in a production setting that ends up as a lot of mechanical PV compression energy and things get hot, so they fan or water cool them.
by Peter Schmelcher
Tue Mar 24, 2020 12:32 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Window dressing - Trying to clean view port glass
Replies: 5
Views: 1344

Re: Window dressing - Trying to clean view port glass

Slightly off topic. My thinking is to cut up an inexpensive stainless camping mirror and stick it in an elbow to reflect the image through a window. The field of view is reduced but perhaps this is ok. Then place some lead between the web cam and the vacuum chamber and hopefully attenuate some of th...
by Peter Schmelcher
Tue Mar 17, 2020 12:31 am
Forum: Vacuum Technology (& FAQs)
Topic: 2 papers about 3d printed vacuum parts
Replies: 1
Views: 693

2 papers about 3d printed vacuum parts

Only mildly interesting. The first one is about ABS and plated ABS, spoiler alert not great. The second paper concludes that laser sintered silver prints are UHV compatible. https://www.researchgate.net/publication/302982473_Vacuum_Compatibility_of_3-D-Printed_Parts https://www.researchgate.net/publ...
by Peter Schmelcher
Mon Mar 02, 2020 5:22 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: A semi-DIY preamplifier for radiation detectors
Replies: 28
Views: 17105

Re: A semi-DIY preamplifier for radiation detectors

Rich you might have a waveform template or limits test feature in your scope. It's a feature in my tds3054 circa 2000. Back in the day the shape of a digital one or zero was a telecom standard. My scope has 8 straight test violation lines (voltage vs time, at any angle). If the analog channel wavefo...
by Peter Schmelcher
Tue Dec 31, 2019 9:56 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Amptek Digital Pulse Processor
Replies: 13
Views: 3117

Re: Amptek Digital Pulse Processor

The attached file is for a different rev of the board PC5 Power Supply User’s Manual Rev. A0 The HV feedback circuit uses a resistor divider which could be changed for a different bias voltage range. One would need to know the HV capacitor ratings or that all model variations use the same HV capacit...
by Peter Schmelcher
Mon Dec 30, 2019 10:54 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Making Large Vacuum Chambers
Replies: 10
Views: 2371

Re: Making Large Vacuum Chambers

I read someplace that cast aluminum is porous and outgasses so it is not good for high vacuum service. I see 300mm diameter 304 stainless garden spheres sell for under $30 on ebay, for example item # 202737785286 or # 153647487022 This is china and who knows the quality or the wall thickness you wil...
by Peter Schmelcher
Thu Nov 28, 2019 9:12 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Fusor construction questions
Replies: 27
Views: 5563

Re: Fusor construction questions

You might consider getting a gas dryer that could also double as a reservoir to isolate the cell. Make the gas in a batch and then later run and adjust the fusor and don't think about the gas generation. ebay item number 150382481448 (Supelco # 20619 Molecular Sieve Water Vapor Trap 200 cc).
-Peter