Search found 696 matches

by Andrew Seltzman
Mon Nov 19, 2018 12:53 am
Forum: Announcements and Site Administration Topics
Topic: Finished PhD, now a postdoc at MIT
Replies: 4
Views: 134

Finished PhD, now a postdoc at MIT

For those of you who don't follow me on facebook, I finished my PhD in plasma physics last year where I demonstrated the first observation of RF heating in the reversed field pinch: My thesis: http://plasma.physics.wisc.edu/uploadedfiles/theses/thesisSeltzman132_2017.pdf A power point of a conferenc...
by Andrew Seltzman
Sun Nov 18, 2018 10:27 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Mark3 operation 3e-4 torr / quad ion source @ -40kV, 1mA-9mA
Replies: 138
Views: 37788

Re: Mark3 operation 3e-4 torr / quad ion source @ -40kV, 1mA-9mA

The thermal camera is viewing the grid during operation, my grid is liquid cooled so it will remain at fairly low temperatures as long as there is coolant flow. There is a little EMI noise on the video, though I have not yet cleaned up the wiring and the video is being sent over twisted pair wire.
by Andrew Seltzman
Sun Nov 11, 2018 2:48 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Mark3 operation 3e-4 torr / quad ion source @ -40kV, 1mA-9mA
Replies: 138
Views: 37788

Re: Mark3 operation 3e-4 torr / quad ion source @ -40kV, 1mA-9mA

The new CNC'd mounting plate for the internal vacuum pumps have arrived and the turbo and diaphragm pump are installed within the fusor frame. Diaphragm pump, turbo pump and MKS-901P gauge for roughing line pressure measurement are mounted on the aluminum plate. SAM_6860.JPG Plate mounts on top of f...
by Andrew Seltzman
Tue Oct 23, 2018 11:13 pm
Forum: New User Chat Area
Topic: Radio waves to increase fusion yield
Replies: 12
Views: 1152

Re: Radio waves to increase fusion yield

Yes, the window would be possible, however you would need to ensure the nipple the window is mounted on will transmit the RF frequency. The nipple would act as a cylindrical waveguide, the cutoff frequency, determined by radius would have to be below your operating frequency (it should be below by s...
by Andrew Seltzman
Wed Oct 17, 2018 4:38 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Mark3 operation 3e-4 torr / quad ion source @ -40kV, 1mA-9mA
Replies: 138
Views: 37788

Re: Mark3 operation 3e-4 torr / quad ion source @ -40kV, 1mA-9mA

More upgrades for the fusor: Upgrades for mounting internal vacuum pumps, custom backing and mounting bracket for the TPD011 turbo pump SAM_6850.JPG Front and back of bracket, replaces the NW16 backing connector and provides 4x 10-32 tapped threads on a 1.75"x97mm pattern SAM_6849.JPG Turbo pump and...
by Andrew Seltzman
Mon Sep 03, 2018 9:58 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Mark3 operation 3e-4 torr / quad ion source @ -40kV, 1mA-9mA
Replies: 138
Views: 37788

Re: Mark3 operation 3e-4 torr / quad ion source @ -40kV, 1mA-9mA

Latest upgrade progress: Diaphragm pump, rough vacuum gauge, and turbo pump to be installed on fusor frame. SAM_6520.JPG CAD design of mounting position: turbo-mount.png Vacuum gauges and turbo pump will share an rs485 bus for communication. The USB to RS485 dongle used for turbo pump testing is the...
by Andrew Seltzman
Mon Aug 20, 2018 11:59 am
Forum: Vacuum Technology (& FAQs)
Topic: Debugging an Inficon PKR 251 Series Gauge
Replies: 3
Views: 592

Re: Debugging an Inficon PKR 251 Series Gauge

Could be a problem with the pirani element, they are known to go bad on these gauges.
by Andrew Seltzman
Sun Jul 08, 2018 10:18 pm
Forum: The Trading Post
Topic: Re: Andrew Seltzman's for sale list updated (3/8/2018)
Replies: 4
Views: 5689

Re: Andrew Seltzman's for sale list updated (7/8/2018)

New hardware on ebay:
https://www.ebay.com/sch/rtftechnologie ... 7675.l2562
Send me an email at andrewseltzman <at> gmail.com (for a better deal/combined shipping) if you are interested in any of the items.
by Andrew Seltzman
Sun Jul 08, 2018 9:50 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Mark3 operation 3e-4 torr / quad ion source @ -40kV, 1mA-9mA
Replies: 138
Views: 37788

Re: Mark3 operation and upgrades

A recent upgrade to the mark 3 has replaced the 6 way conflat cube with an 8 way kimball physics vacuum hexagon. The hexagon is considerably smaller and more compact, and has 2 more ports then the cube. The hexagon is connected to the core with a brazed ceramic isolator with copper conflat o-rings, ...
by Andrew Seltzman
Thu Jul 05, 2018 11:12 pm
Forum: Books & References
Topic: Answer keys w/ explanation?
Replies: 19
Views: 2478

Re: Answer keys w/ explanation?

This is the rutherford scattering problem: http://hyperphysics.phy-astr.gsu.edu/hbase/Nuclear/elescat.html It means assume the atom is free space except for the nucleus which is solid sphere. Calculate the radius of the nucleii and thus the area each nucleii is blocking. Find how thick a foil is req...