Search found 128 matches

by Bruce Meagher
Wed Dec 26, 2018 8:15 am
Forum: Vacuum Technology (& FAQs)
Topic: Poor performance of old diff pump.
Replies: 13
Views: 9649

Re: Poor performance of old diff pump.

Thoughtput on a diffusion pump is closely related to the input power transferred to the boiler and the cooling of the pump. An analogy of a flowing river has been used to described how this works. A slow boil (either too little power transferred to the boiler or too much cooling) will produce a smal...
by Bruce Meagher
Fri Dec 21, 2018 1:18 am
Forum: Vacuum Technology (& FAQs)
Topic: Poor performance of old diff pump.
Replies: 13
Views: 9649

Re: Poor performance of old diff pump.

Marcin, Your english is excellent. I personally have no experience with huge diffusion pumps like yours, but a couple things to consider. Could the DC-704 oil just need to be degassed a bit longer? On smaller diffusions pumps I’ve experienced long initial pump down times with a new charge of oil (ge...
by Bruce Meagher
Mon Dec 10, 2018 10:24 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Gamma-ray Spectrum, CP-1 Graphite Memento
Replies: 15
Views: 8199

Re: Gamma-ray Spectrum, CP-1 Graphite Memento

A few years ago our local university demolished a large shielded room with many tons of low background steel acquired from some pre-WWII ship as well as a bunch of virgin lead. It was unfortunate for sure. One of my professors mentioned that steel made post the atomic era contains radionuclides maki...
by Bruce Meagher
Wed Dec 05, 2018 6:42 am
Forum: Advanced Technical Discussion Area
Topic: A theoretical discussion based on data re. fusor conditioning fusion
Replies: 11
Views: 4849

Re: A theoretical discussion based on data re. fusor conditioning fusion

Richard, A few additional details of what’s involved in your daily set of runs would be useful. How many are done, and how long is each run? Do you believe it’s just a matter of a particular amount of running time with D2, or do you believe shutting down the system and cool everything plays a part i...
by Bruce Meagher
Wed Dec 05, 2018 6:21 am
Forum: Announcements and Site Administration Topics
Topic: Finished PhD, now a postdoc at MIT
Replies: 12
Views: 6011

Re: Finished PhD, now a postdoc at MIT

Congratulations Dr. Seltzman! If you come to San Diego contact me if you’re interested in joining several of us fusor members for one of our meetups.
by Bruce Meagher
Wed Dec 05, 2018 5:51 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Please Help Quantify X-Rays
Replies: 8
Views: 2987

Re: Please Help Quantify X-Rays

My understanding is no MeV X-rays will be produced by heavy energetic charged particles (proton, triton, or He3 particles). Heavy charged particles don’t emit measurable bremsstrahlung radiation when slowing down in the stainless steel shell. Lots of characteristic X-rays from the iron and other ele...
by Bruce Meagher
Tue Dec 04, 2018 12:23 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Please Help Quantify X-Rays
Replies: 8
Views: 2987

Re: Please Help Quantify X-Rays

To get the expected X-ray exposure rate of your fusor you might consider running a Monto Carlo radiation transport simulation with programs such as GEANT4, Gate, MCNP, etc. These programs have fairly steep learning curves, but should provide the results you’re after. Another method would be to hand ...
by Bruce Meagher
Tue Jul 10, 2018 5:12 am
Forum: Vacuum Technology (& FAQs)
Topic: MKS 901p
Replies: 58
Views: 34383

Re: MKS 901p

Rich, try BR? not BD? to get the baud rate.
by Bruce Meagher
Fri Jun 22, 2018 6:15 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Nuclear Enterprises plastic scintillators
Replies: 2
Views: 2311

Re: Nuclear Enterprises plastic scintillators

Saint-Gobain acquired Nuclear Enterprises in the 90s. You might try contacting them to see if you can get the specs. These could be the same as the BC 400 series scintillators they currently offer.

Bruce
by Bruce Meagher
Wed Jun 06, 2018 8:23 pm
Forum: Images du Jour
Topic: Gold Plasma
Replies: 7
Views: 3447

Re: Gold Plasma

Great suggestions Rich. Two experiments to add to the list.

Bruce