Search found 1276 matches

by John Futter
Mon Sep 21, 2020 6:38 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Diy high voltage probe
Replies: 5
Views: 247

Re: Diy high voltage probe

Sarmad I knew you were putting the resistors away from air by potting oil. paraffin, epoxy That is not the point it is the resistors themselves that cannot stand the voltage stress unless specially made for that use. Rich has pointed out a couple of the possible failure mechanisms -there are more! T...
by John Futter
Sun Sep 20, 2020 7:11 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Diy high voltage probe
Replies: 5
Views: 247

Re: Diy high voltage probe

Sarmad Well done I see from the resistors you have used that it is good for 24,000volts with no safety margin ie most small resistors are rated @ 300 volts If you had used VR37 resistors you would have had a theoretical maximum of 280,000 volts I do remember the Silicon chip article as I subscribe t...
by John Futter
Wed Sep 16, 2020 7:34 pm
Forum: Vacuum Technology (& FAQs)
Topic: IR / Visible ZnSe windows
Replies: 6
Views: 387

Re: IR / Visible ZnSe windows

I'm wanting to see an ion beam target with a FLIR camera and see how hot it is getting during implantation and also use it to look at a heated stage in a sputter system

and why so many
the sputter system will tend to coat the window so I got a few spares
by John Futter
Wed Sep 16, 2020 1:36 am
Forum: Vacuum Technology (& FAQs)
Topic: IR / Visible ZnSe windows
Replies: 6
Views: 387

IR / Visible ZnSe windows

New ZnSe windows arrived from China.
I bought 10 of these from china custom made for approx $2000 75mm dia 5mm thick they are stunning
IMG_20200916_133006_228.jpg
by John Futter
Tue Sep 15, 2020 7:00 pm
Forum: Advanced Technical Discussion Area
Topic: Time on a MS system - what isotopes to separate?
Replies: 2
Views: 196

Re: Time on a MS system - what isotopes to separate?

Lithium 6 comes to mind
along with C14 if you make a C14 diamond you can use it as a battery that lasts quite a few thousand years
see
https://newatlas.com/energy/nano-diamon ... rview-ndb/
by John Futter
Sun Sep 13, 2020 7:30 pm
Forum: Interesting Links
Topic: 4hv
Replies: 3
Views: 164

Re: 4hv

Cai
4HV owner is having trouble keeping the site up for various reasons
so most of the users have moved over to
https://highvoltageforum.net/
by John Futter
Sun Sep 13, 2020 7:28 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Restarting Efforts on Demo Fusor II
Replies: 25
Views: 1831

Re: Restarting Efforts on Demo Fusor II

IMHO
milking rubber is much better --it also gives much better vibration isolation from the backing pump
by John Futter
Sun Sep 13, 2020 7:15 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: RF superimposed on HVDC
Replies: 3
Views: 413

Re: RF superimposed on HVDC

Look at how the output tube in ham linear amplifiers feed the anode of the output tube. The DC isolation choke is quite special and is designed so as not to have any resonances in the rf pass band of the amplifier. This done by seriesing several inductors of differing vaues usually on the same forme...
by John Futter
Sun Sep 13, 2020 7:08 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Restarting Efforts on Demo Fusor II
Replies: 25
Views: 1831

Re: Restarting Efforts on Demo Fusor II

Most farm dairy supply stores carry milking rubber. This is what connects the milking claw to the main vacuum pump and pulsator.
Common sizes are half three quarter and one inch bore sizes --sold by the yard and very suitable for backing lines