Search found 1027 matches

by Rich Feldman
Mon Jan 14, 2019 5:05 am
Forum: New User Chat Area
Topic: Rules for Claiming Fusion Clarification
Replies: 10
Views: 547

Re: Rules for Claiming Fusion Clarification

The check list used to include a picture of the maker with the fusor.
I guess that rule was dropped some time around 2016. Anybody remember why?
by Rich Feldman
Fri Jan 11, 2019 2:33 am
Forum: Fusion --- Past, Present, and Future
Topic: Wendelstein 7-X has successfully finished its second major experimental run
Replies: 27
Views: 1863

Re: Wendelstein 7-X has successfully finished its second major experimental run

Re. separation of isotopes. It'd be nice to see the numbers for heavy water next to those for uranium enrichment They might represent two extremes of difficulty, among industrialized separation processes. In between are isotope products with special boron, nitrogen, oxygen, silicon, etc. Dennis's po...
by Rich Feldman
Thu Jan 10, 2019 5:15 pm
Forum: The Trading Post
Topic: End of HSC (Halted Specialties) electronics surplus store in Santa Clara, CA
Replies: 2
Views: 257

End of HSC (Halted Specialties) electronics surplus store in Santa Clara, CA

Yesterday I stopped in at HSC, knowing that the owners had decided to close it down. Signs announced that Saturday, January 12, is the last day of business for the retail store. Hours still 8 to 7 M-F, 9 to 5 Saturday. http://www.halted.com Inventory on the shelves looked a little bit depleted. Clos...
by Rich Feldman
Thu Jan 10, 2019 2:09 am
Forum: Fusion --- Past, Present, and Future
Topic: Wendelstein 7-X has successfully finished its second major experimental run
Replies: 27
Views: 1863

Re: Wendelstein 7-X has successfully finished its second major experimental run

... fusion has only two advantages if working perfectly. 1. it can be immediately shut down....Can't blow up ... To clarify that point: Nuclear fission reactors maintain a chain reaction at the edge of criticality, 24/7/365, but they have not been known to blow up. Chain reaction can be terminated ...
by Rich Feldman
Wed Jan 09, 2019 11:14 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Neutron Test Sources Po210+Be or U238+Be?
Replies: 15
Views: 653

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

Adding to what RIchard said about alpha particles generated inside of rocks (or inside of, say, a chunk of Pu-238 oxide in a heat source for RTG). Alpha particle sources found in consumer products (e.g. Po in Staticmasters, and Am in smoke detectors) have the radioisotope in very thin films, sometim...
by Rich Feldman
Mon Jan 07, 2019 9:32 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Board Mounted LiI(Eu) scintillators - repost in neutron detection
Replies: 19
Views: 7080

Re: Board Mounted LiI(Eu) scintillators - repost in neutron detection

Yes, you need to provide the HV and resistor string. Pinout is given in Hamamatsu PMT datasheet, or you can trace pictures from earlier in this thread. Please let us know, yes or no, if you get a normal PMT signal from any of those units. With or without neutrons. I promise to complete that exercise...
by Rich Feldman
Fri Jan 04, 2019 4:11 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: HV Divider
Replies: 7
Views: 626

Re: HV Divider

It's good that you know about resistor voltage limits, that apply independently of the power limits. Many "1 watt" resistors have formal voltage ratings of only 500 volts (and many 1/2 watt resistors say 350 volts). These voltage limits are softer than those for capacitors and semiconductor devices....
by Rich Feldman
Fri Jan 04, 2019 3:31 am
Forum: Vacuum Technology (& FAQs)
Topic: MKS 901p
Replies: 58
Views: 10355

Re: MKS 901p

New chapter & question (near bottom) in my tale of two MKS 901P's. Both procured via ebay some time last summer, and talked about here. Unit 1 (s/n ending with 2835): Bad start. Plumbed it up and saw analog V_out = +9.45 V with no vacuum. Had previous user programmed it to emulate a different device...
by Rich Feldman
Thu Jan 03, 2019 2:47 am
Forum: New User Chat Area
Topic: Someone give me some exact specs
Replies: 19
Views: 742

Re: Someone give me some exact specs

OK William. After you are proficient at fusing, you are free to profit by producing a ready-to-fly fusor, or selling plans with a bill of materials. The market might be smaller than that for Virgin Galactic's $250,000 tickets, to enjoy a few minutes of microgravity on a suborbital excursion above th...