Search found 128 matches

by Bruce Meagher
Thu May 21, 2020 2:57 am
Forum: Announcements and Site Administration Topics
Topic: Edit posts
Replies: 16
Views: 1081

Re: Edit posts

I was able to fix all my posts (thumbnail missing issue) by deleting the old images as Frank described. I used local copies from my computer for the update. If your photos are not readily available, one could download the images from the forum (before deleting them of course). I only have a few post...
by Bruce Meagher
Mon May 18, 2020 6:12 pm
Forum: Announcements and Site Administration Topics
Topic: Edit posts
Replies: 16
Views: 1081

Re: Edit posts

Frank, Just reposting didn't fix the issue with my thumbnail images. I tried just reposting, I tried making a minor edit and reposting, I tried placing the images inline, and I even tried deleting the captions. None of these methods worked to restore the thumbnail. I still can click on the images an...
by Bruce Meagher
Sun May 17, 2020 5:31 pm
Forum: Announcements and Site Administration Topics
Topic: Edit posts
Replies: 16
Views: 1081

Re: Edit posts

I can clean up my posts if I can have editing privileges for a few days. It does seem there might be a way to fix the image thumbnail missing issue site wide if it's as simple as just re-saving the offending post, but maybe I'm misunderstanding what you did to fix the issue with my particular posts....
by Bruce Meagher
Sat May 16, 2020 3:26 pm
Forum: Announcements and Site Administration Topics
Topic: Edit posts
Replies: 16
Views: 1081

Re: Edit posts

I think the problem Rex mentioned is fairly common on posts from the past few years (prior to the site switch). Below is a list of some of my posts where the image thumbnails do not show up, but the images do displayed when clicked. Is this something each user can fix once discovered, or is there a ...
by Bruce Meagher
Sat Nov 23, 2019 12:38 am
Forum: Vacuum Technology (& FAQs)
Topic: Oil options for rough pumps
Replies: 13
Views: 1621

Re: Oil options for rough pumps

Mark, I respectively disagree with your statement about HVAC oil, and I believe it’s poor advice to provide others on the forum. I was the one that had my son run the test with HVAC oil so he could learn about vapor pressure. Here’s the thread < https://fusor.net/board/viewtopic.php?f=10&t=12189&sta...
by Bruce Meagher
Sat May 18, 2019 5:06 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Ludlum 42-31
Replies: 10
Views: 7487

Re: Ludlum 42-31

One way to determine if you have a BF3 or He3 tube is to look at the output pulse height spectrum. The two spectrums are significantly different. Knoll’s book covers this in detail, but there are many practical examples in past fusor posts. One He3 pulse height spectrum I captured is described in th...
by Bruce Meagher
Sat May 11, 2019 6:31 pm
Forum: Vacuum Technology (& FAQs)
Topic: Poor performance of old diff pump.
Replies: 13
Views: 9860

Re: Poor performance of old diff pump.

Wow that’s an impressive pump! Thanks for sharing and updating your post. I look forward to hearing how your system performs with your new pump. Many of the combo gauges have replaceable Pirani sensor. I’m not sure about your particular gauge (or if it’s really worth your time), but something to con...
by Bruce Meagher
Tue Apr 30, 2019 2:29 pm
Forum: Images du Jour
Topic: More Upgrades
Replies: 14
Views: 9512

Re: More Upgrades

I misinterpreted your previous post. I thought you were implying the D-D fusion cross section decreased above 150 keV. My Bad. Even though there is only a small increase in cross section between say 100 and 200 keV the neutron production rate more than doubles over this interval. However, as your ri...
by Bruce Meagher
Sat Apr 27, 2019 6:51 am
Forum: Images du Jour
Topic: More Upgrades
Replies: 14
Views: 9512

Re: More Upgrades

Richard, I believe you are quoting the D-T cross-section curve (not the D-D cross-section) in your comment above. The D-D fusion cross-section doesn't fall off until a few MeV. Below is a graph of the different fusion reaction cross-sections vs energy taken from: http://www.kayelaby.npl.co.uk/atomic...
by Bruce Meagher
Tue Apr 23, 2019 5:59 pm
Forum: Images du Jour
Topic: Starting fusor build
Replies: 2
Views: 3163

Re: Starting fusor build

Luke, Here are a few comments on your nice setup... Have you considered the expected temperature your grid will reach during operation? At fusion producing power levels will your silver brazed connections hold? Jon R. had a nice post about his grid design and how he mechanically attached the grid to...