Search found 30 matches

by Luke Harrill
Fri Feb 22, 2019 6:22 pm
Forum: Images du Jour
Topic: Fusor Progress, Luke Harrill
Replies: 11
Views: 2113

Re: Fusor Progress, Luke Harrill

My first light!! (on 2-18-19) I couldn't wait any longer to start testing, so I wired the XRT to 120 VAC, threw together a grid, pumped the system down, and turned on the variac. I initally used only the Welch to get down to ~20 microns before turning on the power. After a bit of cleaning, I was dow...
by Luke Harrill
Fri Jan 25, 2019 5:14 am
Forum: New User Chat Area
Topic: Silver Solder for HV Insulator
Replies: 11
Views: 1122

Re: Silver Solder for HV Insulator

Update! I decided to test the seal before I installed the stalk. I plugged the top of the feed through by polishing it and placing a rubber stopper under a SS cap (with a tiny bit of Apizon M). I pulled down to 25 microns and turned on the turbo. I got down to 6.00E-5 torr before sealing off the cha...
by Luke Harrill
Fri Jan 11, 2019 5:58 pm
Forum: New User Chat Area
Topic: Silver Solder for HV Insulator
Replies: 11
Views: 1122

Re: Silver Solder for HV Insulator

I think I will definitely implement that idea, Dennis! Thank you so much for your input!

-Luke Harrill
by Luke Harrill
Fri Jan 11, 2019 3:56 pm
Forum: New User Chat Area
Topic: Silver Solder for HV Insulator
Replies: 11
Views: 1122

Re: Silver Solder for HV Insulator

Well, impatience got to me last night when I decided to tin the SS flange. I began by placing it on two fire bricks and heating it with a butane pencil torch. That was taking forever, so I stepped it up to a large, rose-tipped propane torch. After it got pretty hot, I lightly fluxed a ring around th...
by Luke Harrill
Wed Jan 09, 2019 4:48 pm
Forum: New User Chat Area
Topic: Silver Solder for HV Insulator
Replies: 11
Views: 1122

Re: Silver Solder for HV Insulator

I will certainly pre-tin the surface, but do you also agree that I will be able to safely solder the stalk into the flange with this low-temp stuff? My fear is that the fusor will overheat the joints during operation. I wouldn't want to lose vacuum and kill my turbo or xrt. Also, Rex, here is the FA...
by Luke Harrill
Wed Jan 09, 2019 4:33 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Neutron Test Sources Po210+Be or U238+Be?
Replies: 15
Views: 1279

Re: Neutron Test Sources Po210+Be or U238+Be?

Really this should have been asked in the new user area, as this is already explained in the FAQ.

viewtopic.php?f=31&t=5316
viewtopic.php?f=31&t=5504

I'm unsure of what you measured it with, but 62kcpm isn't exactly a hot rock.

-Luke Harrill
by Luke Harrill
Tue Jan 08, 2019 10:44 pm
Forum: New User Chat Area
Topic: Silver Solder for HV Insulator
Replies: 11
Views: 1122

Silver Solder for HV Insulator

A little while back, I purchased a HV insulator from Richard. I now have a 6" CF flange with a hole to seat the silver-plated brass skirt. I went to the local welding store and found a "STAY-BRITE Silver Solder Kit" which included some flux and 3.5/96.5 Ag to Sn solder. I read the FAQ about repurpos...
by Luke Harrill
Sun Jan 06, 2019 3:50 am
Forum: Vacuum Technology (& FAQs)
Topic: The Importance of TC Gauge Calibration
Replies: 10
Views: 1605

Re: The Importance of TC Gauge Calibration

Update: According to Bruce's gauge, my 1402 can pump down to 5.3 millitorr after ~15 min. I'm now waiting for an iso63 adapter to come in so that I can hook up both gauges at once.

-Luke Harrill
by Luke Harrill
Wed Jan 02, 2019 3:17 am
Forum: Vacuum Technology (& FAQs)
Topic: The Importance of TC Gauge Calibration
Replies: 10
Views: 1605

Re: The Importance of TC Gauge Calibration

Thank you so much, Bruce! With the lower end of that tube I will also be able to calibrate some of my ion gauge scales as well. Does it have the standard kf16 fitting? I'll soon be ordering an iso63 to cf adapter for my turbo (then I will be able to pump down that far). It is great to hear that abou...
by Luke Harrill
Wed Jan 02, 2019 3:04 am
Forum: Images du Jour
Topic: Fusor Progress, Luke Harrill
Replies: 11
Views: 2113

Re: Fusor Progress, Luke Harrill

Thanks, Dennis! Richard, you are right on spot with the dates, as there are two stickers from '68 and '70 on it! You would have also noted the 2 sprague "atom" caps, but I had already replaced them when I took the photo (and cleaned the pot too). I have found 2 solder points that broke loose when I ...