Search found 409 matches

by Mark Rowley
Mon Apr 06, 2020 3:46 am
Forum: Images du Jour
Topic: Liquid cooled Demo Fusor cage
Replies: 4
Views: 159

Re: Liquid cooled Demo Fusor cage

Hi Dominick Excellent work! Keep puttering with the demo fusor until funding comes in for the bigger things. Like Scott, I too started here many years ago but didnt get a neutron producing fusor in play until last year. During my demo fusor days I enjoyed experimenting with different grid designs an...
by Mark Rowley
Sun Apr 05, 2020 8:10 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Simple Cold Trap for PEM Cell Deuterium
Replies: 3
Views: 74

Re: Simple Cold Trap for PEM Cell Deuterium

Hi Rich At the same operating parameters I’d normally get ~4000cpm on the neutron detector. With the cold trap it’s around 8000. D2 flow rate and pressure were as close to the same as I could manage it. Good question about the level of moisture. I believe Bob said he saw condensation in his PEM cell...
by Mark Rowley
Sun Apr 05, 2020 5:15 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Simple Cold Trap for PEM Cell Deuterium
Replies: 3
Views: 74

Simple Cold Trap for PEM Cell Deuterium

After mixed results with Drierite, I decided to move forward with the cold trap as an alternative approach. After today’s test, I am very pleased with the results. The cold trap improved my neutron output by close to 50%. Using the same power input that normally generates 4000cpm on the CHM11, the c...
by Mark Rowley
Sat Apr 04, 2020 4:16 am
Forum: Other Forms of Fusion - Theory, Construction, Discussion, URLs
Topic: Columbus-I Pinch Tube Build
Replies: 54
Views: 26642

Re: Columbus-I Pinch Tube Build

Over the past couple weeks I swapped out the pinch tube with certified fused quartz from a reputable supplier. I also machined two new electrodes to accommodate the slightly different tube size as well as to move the D2 inlet to the bottom electrode. 15A56CB7-D9B3-490D-ABBB-DC89BBEFF7BE.jpeg After v...
by Mark Rowley
Mon Mar 30, 2020 5:30 pm
Forum: Vacuum Technology (& FAQs)
Topic: Leak in vacuum system (diffusion pump?)
Replies: 12
Views: 474

Re: Leak in vacuum system (diffusion pump?)

Hi Thomas, I have to reiterate on what Richard said. You have way too much plumbing between your diffusion pump and Fusor chamber. I’d venture a guess that your plumbing has close to 3 times the total volume of the Fusor! That elbow coming through the desk is easily large enough to suffice for a Fus...
by Mark Rowley
Fri Mar 27, 2020 5:38 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Power Supply from an "interesting" XRT
Replies: 14
Views: 1613

Re: Power Supply from an "interesting" XRT

As a group we should not offer hope that these smaller XRTs work for Fusor use. I also traveled down this rabbit hole of smoked secondaries and was met with the same results. The entire forum is littered with similar failures. Yes, one does learn some things but it's hardly worth the wasted time and...
by Mark Rowley
Sun Mar 22, 2020 9:15 pm
Forum: Interesting Links
Topic: "Nuclear Physics Lab" Website
Replies: 4
Views: 343

Re: "Nuclear Physics Lab" Website

John,
Link works fine on both my smartphone and laptop.

Mark Rowley
by Mark Rowley
Sun Mar 22, 2020 4:22 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Building an Inexpensive HV Feedthrough: The Complete Saga
Replies: 5
Views: 856

Re: Building an Inexpensive HV Feedthrough: The Complete Saga

James Enright, This is a great design you might consider. Cost effective wise, you can’t go wrong. Same goes for a window. Some o-rings, a pyrex window and a couple of lightly machined aluminum discs will mate up with a conflat flange with ease. Total cost would most likely be $40 or less. Mark Rowley
by Mark Rowley
Sat Mar 14, 2020 5:11 pm
Forum: Other Forms of Fusion - Theory, Construction, Discussion, URLs
Topic: Update on experiment
Replies: 20
Views: 2363

Re: Update on experiment

We normally use mTorr or Microns for scientific vacuum work and I believe your electronic meter can toggle to those measurement units. If not, using an online conversion tool would be a good idea. So that's around 188 mTorr which is still not good......better, but not good, especially if the measure...
by Mark Rowley
Tue Mar 10, 2020 11:13 pm
Forum: Vacuum Technology (& FAQs)
Topic: McMaster Carr's oddly inexpensive turbopump
Replies: 7
Views: 548

Re: McMaster Carr's oddly inexpensive turbopump

Richard, I’m with ya on the diff pumps. One can look back in these forums and see that a very high percentage of turbo pump users only achieved successful operation by two primary means. Lots of money OR a very complex ordeal building a controller for a pump that many times is later found out to be ...