Search found 1564 matches

by Frank Sanns
Sat Aug 12, 2017 6:12 pm
Forum: Announcements and Site Administration Topics
Topic: Can we have SSL?
Replies: 13
Views: 2720

Re: Can we have SSL?

Sometimes the cure is worse than the disease. The site has been returned to its original state.
by Frank Sanns
Thu Aug 10, 2017 3:50 pm
Forum: Announcements and Site Administration Topics
Topic: Can we have SSL?
Replies: 13
Views: 2720

Re: Can we have SSL?

Comodo is free only for the first 90 days. Let's Encrypt on the server is not something I am wild about. Before paying for something what is the cost to benefit ratio? In understand people can see what we are reading but it is a public forum that everybody can read anyway. Yes it could be intercepte...
by Frank Sanns
Wed Aug 09, 2017 10:35 pm
Forum: Announcements and Site Administration Topics
Topic: Can we have SSL?
Replies: 13
Views: 2720

Re: Can we have SSL?

Done.

Let me know if it is working for everybody or if there is any problem.
by Frank Sanns
Tue Aug 01, 2017 2:13 pm
Forum: Announcements and Site Administration Topics
Topic: Editing one's posts on the board?
Replies: 5
Views: 1186

Re: Editing one's posts on the board?

It used to be that forum members had an unlimited amount of time to edit or delete but this caused problems. It was reduced to one week and still, on occasion, for reasons unknown, people would kill a thread or threads. For that reason, I cut the edit or delete time down to two hours. I figured that...
by Frank Sanns
Wed Jun 14, 2017 12:01 am
Forum: New User Chat Area
Topic: Stainless steel pipe chamber
Replies: 39
Views: 7436

Re: Stainless steel pipe chamber

While the surface roughness contributes to surface area that can hold moisture, it is the pores and interfaces that are more of the problem. Polishing the inside will gain some advantage for pressures lower that 10E-4 or 10E-5 torr but it will do nothing to remove the pores that hold onto air and mo...
by Frank Sanns
Mon Jun 12, 2017 11:01 pm
Forum: New User Chat Area
Topic: Boards for Bob Higgins slow neutron detector
Replies: 8
Views: 1437

Re: Boards for Bob Higgins slow neutron detector

A gamma source that is well above the background count is what is needed. The 1B24 should be quite fine for that purpose. The source lets you brings the threshold up up on the detector so it just does not detect any of the gamma coming from the radium. You could do it with a fairly paltry source but...
by Frank Sanns
Wed Jun 07, 2017 9:33 pm
Forum: New User Chat Area
Topic: Boards for Bob Higgins slow neutron detector
Replies: 8
Views: 1437

Re: Boards for Bob Higgins slow neutron detector

There must be old radium dial clocks, watches, or aircraft gauges available. They make perfect check sources and for nulling out background for neutron tubes.
by Frank Sanns
Fri Jun 02, 2017 2:58 am
Forum: New User Chat Area
Topic: The Maths Needed
Replies: 4
Views: 977

Re: The Maths Needed

These are easy calculations.


Gas flow=deuterium flow+leak rate+outgassing

Neutron emission=0.5 x fusion rate

Temperature (K)= 1.16E4 input voltage

Electric field (V/m)= Input V/inter grid distance

Magnetic field=There are no magnets. The fusor is symmetrical so no net magnetic field.
by Frank Sanns
Fri Apr 28, 2017 9:34 pm
Forum: New User Chat Area
Topic: Better alternative to glass as a first vacuum chamber
Replies: 2
Views: 812

Better alternative to glass as a first vacuum chamber

I have no idea why so many new people want to use glass as their chambers. IT IS DANGEROUS TO USE GLASS. It can get a beam hot spot and implode sending shards of glass everywhere even sometimes through a scatter shield. It also does not stop soft x-rays so it does not provide a shield area for the o...
by Frank Sanns
Thu Apr 27, 2017 3:46 am
Forum: Vacuum Technology (& FAQs)
Topic: Has anyone used these small plastic vacuum desiccators?
Replies: 7
Views: 1619

Re: Has anyone used these small plastic vacuum desiccators?

The glass variant with high vacuum grease on the mating surfaces and the vacuum port on the lid will hold a decent vacuum for a long time as in months. No outgassing there and a very slow leak down rate. The other technique with these is to put some desiccant in them to keep totally dry if any air g...