Search found 164 matches

by Peter Schmelcher
Sun May 10, 2020 9:15 pm
Forum: Announcements and Site Administration Topics
Topic: Coronavirus pandemic
Replies: 133
Views: 18540

Re: Coronavirus pandemic

I wondered how it was going in Oregon. Contact tracing here suggests that BC got its first infection back in January from a person shopping at a Costco in Washington state. I think our total death numbers (127) are skewed to older people because of cluster infections at old age assisted living facil...
by Peter Schmelcher
Sun Apr 12, 2020 1:57 am
Forum: Vacuum Technology (& FAQs)
Topic: First ever Turbo experience
Replies: 38
Views: 6939

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: 776

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
Fri Mar 20, 2020 6:06 am
Forum: Announcements and Site Administration Topics
Topic: Coronavirus pandemic
Replies: 133
Views: 18540

Re: Coronavirus pandemic

I don’t chime in on these discussions but B-b-b-baby, you just ain't seen n-n-nothin' yet. If you are in the ignorance is bliss camp stop reading now. If the government does a fantastic job informing society of the danger and people listen and change their behavior the death rate could be as small a...
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: 312

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: 15081

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: 2205

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: 1668

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: 3797

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
by Peter Schmelcher
Sat Aug 31, 2019 6:11 pm
Forum: FAQs: Neutron - Radiation Detection
Topic: FAQ - Neutron Transport Simulation, Detector Calibration, and Shielding
Replies: 10
Views: 6552

Re: FAQ - Neutron Transport Simulation, Detector Calibration, and Shielding

Nice work!

Another arrow in your quiver could be Cosmic ray generated neutrons. For initial testing, does my detector setup work, it’s a no brainier. For calibration it remains an unanswered question.

Previous post with attached papers.
viewtopic.php?t=11307

-Peter