Search found 72 matches

by Bruce Meagher
Thu Nov 16, 2017 11:25 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Neutron Scintillation Tube/Counter
Replies: 33
Views: 971

Re: Neutron Scintillation Tube/Counter

Dennis, Wrong person. I still have plans to do pulse shape descriminatiin with some of my bc-412 stockpile. Unfortunately, I have many plans, each one moving forward at a glacially slow pace.

Bruce
by Bruce Meagher
Wed Nov 15, 2017 7:33 pm
Forum: Ion Gun Design and Construction (& FAQs)
Topic: Deuterium Accelerator and Electro-Static Power Supply
Replies: 18
Views: 958

Re: Deuterium Accelerator and Electro-Static Power Supply

Dennis, Nice to see that you’re continuing your electrostatic accelerator efforts. As Finn mentioned you want to get as much charge on the belt as possible. Belt material (with high surface resistivity), width, speed and comb design will determine how much current your VdG will get to the terminal. ...
by Bruce Meagher
Wed Nov 15, 2017 4:36 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Neutron Scintillation Tube/Counter
Replies: 33
Views: 971

Re: Neutron Scintillation Tube/Counter

If you want to detect fast neutrons properly with these plastic scintillators you need to implement pulse “shape" discrimination. The shape of the light output from a gamma event compared to a neutron event (longer tail) is sufficiently different that it is relatively straight forward to design a ci...
by Bruce Meagher
Wed Oct 18, 2017 9:04 pm
Forum: Announcements and Site Administration Topics
Topic: Paging Garrett Young
Replies: 5
Views: 332

Re: Paging Garrett Young

I bought one of his supplies back in June, but never received it. I’ve been unable to reach him for months. I’m hoping the power supply didn’t get the better of him.

Edit. Removed email address.
by Bruce Meagher
Thu Sep 21, 2017 7:32 pm
Forum: Images du Jour
Topic: Fusor progress, Finn Hammer
Replies: 21
Views: 1075

Re: Fusor progress, Finn Hammer

From your picture above it appears there is some pitting in your weld on the inside of your chamber. I’d imagine this will limit the ultimate pressure you can achieve, but I do not have any practical experience to say what that limit might be. Fusors do not require much of a vacuum in the scheme of ...
by Bruce Meagher
Tue Sep 12, 2017 5:11 pm
Forum: Images du Jour
Topic: A good deal.
Replies: 9
Views: 525

Re: A good deal.

Have you checked transducer status @254T?;FF on you Quattro 999 to verify your hot cathode filament is ok (when the pressure is below 5mTorr)? As Andrew mentions make sure you have at least a 90 degree bend so the gauge doesn’t have line of sight to the pump. An instructive exercise would be to put ...
by Bruce Meagher
Wed Sep 06, 2017 9:20 pm
Forum: Vacuum Technology (& FAQs)
Topic: MKS Quattro
Replies: 15
Views: 776

Re: MKS Quattro

I believe @254;FF is the shortest string you can send and still get a response from the device (explained near the end of the manual on debugging the comm link)
by Bruce Meagher
Wed Sep 06, 2017 5:25 am
Forum: Vacuum Technology (& FAQs)
Topic: MKS Quattro
Replies: 15
Views: 776

Re: MKS Quattro

Roberto, Some things you might double check before completely disassembling... Verify you didn’t mix up the +/- signals. Check your RS485 adaptor is setup as 8 data bits, no parity, and one stop bit (in half duplex mode bridge T+ to R+ and T- to R-). Check all 6 different baud rates (9600 is the def...
by Bruce Meagher
Wed Aug 30, 2017 8:44 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Bonding Tungsten and/or Iridium?
Replies: 25
Views: 1408

Re: Bonding Tungsten and/or Iridium?

Ian, As Jerry and others have mentioned, ideally you want a transformer whose secondary has one or two turns to make proper spot welds. You’re after gobs of current for a very short interval (with pressure). Check out the attached two documents for a great primer on the subject. Of course you can we...
by Bruce Meagher
Sun Aug 20, 2017 1:42 am
Forum: Images du Jour
Topic: Progress on my fusor
Replies: 28
Views: 1905

Re: Progress on my fusor

Have you tried removing the vanes (labeled 29 on the parts list) and retightened the bolts to see if they are the cause? Since the pump was working previously maybe you just reinstalled the vanes incorrectly.