Always be Knolling

29 04 2012

A friend of Stuart’s recently introduced me to knolling.


  1. Scan your environment for materials, tools, books, music, etc. which are not in use.
  2. Put away everything not in use. If you aren’t sure, leave it out.
  3. Group all ‘like’ objects.
  4. Align or square all objects to either the surface they rest on, or the studio itself.

It’s a more deliberate version of “cleaning up”.

Hot Cathode Electron V2

29 04 2012

All photos.

Today I’m taking some small steps toward building hot cathode electron gun v2.

Here is a physical diagram and schematic:

This is the hot cathode intended for  an electron beam welder. It has 34 mΩ resistance:

The parts of the electron gun will be arranged like this:

This is more simple than most electron guns. I don’t need a carefully focused beam, I just want to shoot a crude beam of electrons into the Polywell.

The next step is to design and build a simple armature to hold the pieces together.

Electron Gun Redux

16 04 2012

The hot cathode electron gun has been a real pain in the ass.

Based on comments we may have one or more of these problems:

1) The hot cathode has been fouled by operation in normal atmosphere. I tried to avoid this, but who knows.

2) When I removed the CRTs glass casing, I may have removed a high voltage anode.

3) The phosphor screen may not be grounded well enough, causing deflection of the electron beam by charge accumulation.

4) The vacuum pressure is too high, scattering the electrons.

5) Something else.

My plan is to set aside the CRT based  electron gun, and try to build a simplified electron gun from scratch.

Previously I purchased a fresh hot cathode designed for electron beam welding.

The gun will consist of a hot cathode floating at -100V and a copper tube segment at +2000V for acceleration. A grounded phosphor screen will reveal any beam that forms.

Prometheus Fusion Perfection has an Intern

15 04 2012

Hi everybody, I’m Domenick Bauer, and in about a month, I will begin a full-time internship at Prometheus Fusion Perfection.

Let me say a little about how I came to find Prometheus. I’ve done some fusor work in the past, and a few years ago, I built a Farnsworth-Hirsch fusor capable of star mode. Unfortunately I had to return to school before I could make a real attempt at fusion. Since then, I have been an avid follower of the fusion effort. Earlier this year, I came upon this blog, and found it very exciting.

I wanted to be a part of it, but knew that money was tight at Prometheus, so I applied for the Hodson Trust Internship Program, a fellowship offered by my school in which an applicant creates a proposal on something interesting he wants to do, and finds an organization where he can do it. If the Hodson committee likes the proposal and the organization, the applicant is awarded a stipend on which he can live while he does his internship.

Yesterday, I learned that I was awarded the internship!

It feels great to be here at Prometheus and I can’t wait to get started.

Blink / Steady – The bike light you’ve been waiting for.

12 04 2012

My shop-mate Stuart just launched a kickerstart for quite possibly the best bike light ever made.

The light is made from aluminum milled right here in the shop we share.

The light is practically impossible to steal without removing the seat post. It senses your motion and turns on/off automatically. And the battery lasts longer than your typical bike light. It’s a tiny marvel of engineering.

Stuart is a master craftsman. I’ve seen him design and ship stunning robotics and dynamic sculptures over the years.

Stuart is a HUGE contributor to my fusion research. He taught me everything I know about prototyping.

So do yourself a favor and buy the last bike light you’ll ever buy.

LIFT Conference Talk

4 04 2012

My talk at the LIFT conference in Geneva has been posted online!

CERN / Large Hadron Collider Visit

29 02 2012

All photos.

Last week I was in Geneva doing a talk at LIFT 2012, which I will post when it goes online. As part of the conference I was invited to tour CERN and the Large Hardron Collider. Despite a hungover 7AM wakeup I managed to make the train to CERN. What an amazing experience!!

A cutaway showing how the beam line section are connected. The beam line tubes contract several centimeters as they are cooled with liquid helium, so bellows and sliding joins are used:

This is the main testing facility for beam line tubes:

This is a cavity resonator used in the Large Electron Positron Collider – the predecessor to the LHC:

Here we see the control room for the Large Hadron Collider. SO COOL.

James Bridle , who spoke at LIFT, wrote a nice post on our CERN visit.

Vacuum Check

11 02 2012

All photos.

I have Swiss TV journalist Yves Gerber in the lab today. I will try the electron gun again while he is here.

Previously in the comments, Olivier suggested the vacuum pressure is too high. Indeed, at 1.66 millitorr the pressure was higher than I wanted.

My first goal today is to check the empty vacuum chamber with blank flanges. A best case scenario.

With the initial pump down I only got down to ~3 millitorr…  about the same as last time. I used the stethoscope to listen for a leak but did not hear one.

I tried tightening the flanges one last time, and suddenly the pressure started dropping again.  I forget how much torque these conflat flanges need to fully seal.

Now I am seeing pressure in the range of 0.098 millitorr and dropping. Much better!

So now let’s install the electron gun, and see what we get.


With the electron gun components in the chamber I am able to get down to 0.27 millitorr… not bad!

But when I turn on the electron gun… still no beam.


PROTEST National Defense Authorization Act

15 12 2011

We are on the verge of loosing the right to habeas corpus in America.

The National Defense Authorization Act of 2012 was passed by the House last night and the president is expected to sign it into law.

Forbes has a good article on the threat this law poses to civil liberties in the United States.

This law allows the US  government to indefinitely detain US citizens without trial.

If the government doesn’t like you… they can brand you a terrorist and make you disappear.

This makes every US citizens vulnerable to unjust prosecution.


I will be at Zuccotti Park  40 Foley Square NYC protesting today.



Information on the NDAA has been tough to find with lots of confusion on the internet.

Lawfare has a great FAQ that gets into the subtleties of the NDAA.


UPDATE: President Obama has signed the National Defense Authorization Act into law.


13 12 2011

All photos.

Today I did another test of the CRT based electron gun in the vacuum chamber.

Spoiler alert: I didn’t see an electron beam.

This time I put a grounded piece of phosphor right in front of the beam path:


Here is a closeup of the grounding wire:

I printed the phosphor holder with 1% infill so it’s basically hollow, then I drilled it with holes to allow gas to escape:


The vacuum reached 1.66 millitorr which is not amazing, but good enough for this run.

I tested the wiring with the unbroken CRT, and it looked good:


Then I wired the power supply to the vacuum chamber feedthrough:

The I fired it up, you can see the hot cathode working:

But no beam.


%d bloggers like this: