Search found 962 matches

by Rich Feldman
Fri Jul 20, 2018 5:56 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Maximus Energy NEUTRON-PRO neutron detector
Replies: 2
Views: 407

Re: Maximus Energy NEUTRON-PRO neutron detector

I'd imagine a HV circuit that generates impulsive E-field noise will also generate impulsive H-field noise. In both cases it's a near field issue, 'cause we want the neutron detector to be right next to the fusor. Does the product under discussion include magnetic shielding, to reduce voltages induc...
by Rich Feldman
Mon Jul 16, 2018 2:27 pm
Forum: New User Chat Area
Topic: Working Diffusion Pump?
Replies: 7
Views: 338

Re: Working Diffusion Pump?

It's analogous to the water input port for a teakettle. tk.jpg Did you think the DP consumes fluid in normal operation? You can learn a lot about them from the Internet without posting questions to people. Maybe you guys can divide up the work. Browse this forum. Search this forum. Read the FAQs. Br...
by Rich Feldman
Sat Jul 14, 2018 11:49 pm
Forum: New User Chat Area
Topic: VACUUM CHAMBER
Replies: 5
Views: 302

Re: VACUUM CHAMBER

>> most glass-based devices would implode at the 5-20 micron range. Joshua, we have to interrupt before a serious misconception is propagated. How much does the implosion risk change between a 7.6 torr vacuum and a 7.6 micron vacuum? The material stresses, from exterior-interior pressure difference...
by Rich Feldman
Sat Jul 14, 2018 3:28 am
Forum: Books & References
Topic: Answer keys w/ explanation?
Replies: 19
Views: 864

Re: Answer keys w/ explanation?

Full credit for that one. At least, your bottom line matches mine from last week. [edit] The step about layers is handy, and leads to the right answer. But it's not necessary. It might reinforce the usually wrong idea that atoms really do crystallize in neat x-y-z cubic lattices. My suggestion to lo...
by Rich Feldman
Wed Jul 11, 2018 10:17 pm
Forum: New User Chat Area
Topic: Pre-Testing a Vacuum Diffusion Pump
Replies: 3
Views: 223

Re: Pre-Testing a Vacuum Diffusion Pump

There's an easy additional test, reported here by Muhammad Faizdul. http://www.fusor.net/board/viewtopic.php?f=18&t=11088&p=73737 After cleaning the empty chamber, he filled it halfway with water and brought it to a boil. OP mentions one hazard. boiler.PNG Roberto already mentioned water filling as ...
by Rich Feldman
Tue Jul 10, 2018 12:56 am
Forum: Images du Jour
Topic: Corrosion cleanup yet again
Replies: 7
Views: 1077

Re: Corrosion cleanup yet again

Found yet another kind of grease that oily/creamy hand cleaner is good for. Tacky, semi-dried cooking oil deposits on an exhaust fan grille. DSCN0657.JPG As Rex said, you can apply a substantial thickness and it'll stay in place for a while. It did a number on the chrome spray painted surface. Its o...
by Rich Feldman
Mon Jul 09, 2018 11:35 pm
Forum: Vacuum Technology (& FAQs)
Topic: MKS 901p
Replies: 54
Views: 5888

Re: MKS 901p

Yay! One MKS901P is all better now, after some hand-typed serial communication using Tera Term. That users-manual figure copied by Rex resolves, on close inspection, the proper TD and RD connection to RS-232 port with a DE-9 connector. A voltmeter gave the same answer: when unconnected, each device'...
by Rich Feldman
Sun Jul 08, 2018 1:03 am
Forum: Books & References
Topic: Answer keys w/ explanation?
Replies: 19
Views: 864

Re: Answer keys w/ explanation?

Ameen, you're inviting confusion by trying to apply an all-steps-in-one formula that you don't understand. Andrew and Dennis and I are walking you through a more step-by-step approach, based on fundamentals. When you get the answer that way, then you can confidently take apart the Rs/Ri formula from...
by Rich Feldman
Sat Jul 07, 2018 4:22 am
Forum: Books & References
Topic: Answer keys w/ explanation?
Replies: 19
Views: 864

Re: Answer keys w/ explanation?

First half looks correct, up to and including your value for nuclear diameter: 1.70E-12 cm (or 1.36E-12 if we use the smaller value for r0). Applause for your typography with rhos and square root symbols. The only ones I remember how to get without menus are Ω and °. Let's see if someone else steps ...
by Rich Feldman
Fri Jul 06, 2018 7:51 pm
Forum: Books & References
Topic: Answer keys w/ explanation?
Replies: 19
Views: 864

Re: Answer keys w/ explanation?

Don't be so modest, Ameen. You already know more about nuclear science than 99.9% of the world's 14yo's. The equation from the book r = r0 A^1/3 gives the radius of the nucleus where r0 is a constant that is equal to about 1.5 x 10^-13 cm Solving for the radius: Solving for the volume gives us 2.55 ...