Batch of New Parts

September 5, 2014 at 11:02 pm

It’s been quite a while since my last post, but lots of new parts.  All the main parts (pumps, chamber, power supply, deuterium, neutron detection system) have either arrived or are ordered, meaning that all that is left are some small parts which are mostly on the way too.  Everything should be available by October, bar one or two items.

In other news, two members of the Brand Irish production team, a documentary about the Irish and their “Brand” around the world came to my  house three weeks ago to film a piece for the movie.  They spent a few hours interviewing me about the Fusor and opinions on science and technology in Ireland.  The film is due to premiere in March 2015.

Fusor Brand Irish Tom McCarthy Craig Hastings Sara Gibbings

With members of Padi Padi Productions, Craig Hastings, cameraman on the left and Sara Gibbings, executive producer and director on the right.

Also, My interview with Michael McAndrew, of Talks About Tech was also released.  I met Michael at an event in the NUI Galway College Bar in July and he was interested in interviewing me for a podcast and everything went well from there.  Podcast.

Last, I’ve been doing some small bits with the website itself.  Most noticeably I’ve added a column with Sponsor’s logos on the left column on each page – scroll down a bit if you can’t see it.  I’ve been working on the Supporter’s page too, in reality there’s not too much to it, but I tend to procrastinate, so it could be in the next few days that it goes up, or in two weeks time…

Now, on to the parts:

Mechanical Vacuum Pump:

This is an Edwards RV3 two-stage rotary vane pump that was donated to the Fusor free of charge (the donor would prefer to remain anonymous).  It has been used a bit, but is in perfect condition.  I’ve ordered new oil for it and new oil along with a clean out should ensure it is in full working order.  According to Edwards, its ultimate pressure is 1.5 microns (1.5 x 10-3 torr) and it has a pumping speed of 2.6 CFM, which is excellent for the Fusor.

Edwards RV3 vacuum pump hose Fusor fusion Tom McCarthy

Edwards RV3 pump, connected hose came with it, KF25 connections.


Turbo-molecular Vacuum Pump:

The turbo-pump I acquired for the Fusor is an Oerlikon-Leybold 151.  It was sponsored by Provac Ireland, one of the main vacuum suppliers in the country (Provac provided Dr McCarthy, in UCC’s vacuum set-up).  The vacuum pump is newly refurbished with controller and associated cabling, which is worth quite a lot.  It pumps at a speed of 145 liters/second for Nitrogen and has an ultimate vacuum of 7.5 x 10-11 torr (1 x 10-10 mbar), which is absolutely fantastic for the Fusor.  One picture for now, better ones to come.

Tom McCarthy, Fusor turbo-pump vacuum Provac fusion vacuum pump

Myself with the turbo-pump, just opened, it has a DN100 conflat inlet.


Neutron Detection System:

The neutron detection system I’m using for the Fusor is a Gamma Spectacular GS-2000-PRO hooked up to a helium-3 neutron detection tube.  I posted pictures of the he-3 tube I bought previously, but cannot currently use it with this set-up as I have to get some coaxial cable and  make a custom connector for it.  However, Steven Sesselman, who runs Gamma Spectacular and has built his own Fusor has given me one of his own he-3 tubes on loan until.  Steven also built me a custom pre-amp to work with my own he-3 tube as it is a Russian CHM tube that takes a different pulse than American tubes, which the GS units are built for.  Steven’s a brilliant guy and has a lot of different spectroscopy products available on his site…You can also check out his forum where he posts his musings on theoretical physics:

Tom McCarthy Steven Sesselmann Fusor fusion neutron detection gamma he-3 tube

Gamma Spectacular set-up. The White cylinder is a HDPE moderator with He-3 tube and the left and right boxes are the custom pre-amp and 2000V bias, respectively.


Tom McCarthy Steven Sesselmann Fusor fusion neutron detection gamma he-3 tube

Specifications sheet on HDPE moderator for He-3 tube.


Photomultiplier Tube/Optical Grease:

Another item I’ve bought related to detection is a photomultiplier tube.  It has a 3″ diameter circular face.  I’ve been looking for an affordable sodium iodide crystal to use with it, but nothing’s come up.  If anybody could point me in the direction of one, I’d be very grateful.  There are 3″ BGO crystals available on Ebay, but I’d rather an NaI (Tl) one.  I also bought 10ml of optical grease for mating whatever crystal I end up getting to the PMT face.

Fusor gamma neutron x-ray detection photomultiplier tube Tom McCarthy

Face of the photomultiplier tube, quite a nice picture actually.


PMT photomultiplier Fusor fusion paint can specs nai detection neutron gamma x-ray Tom McCarthy

Photomultiplier tube specifications.


Tungsten Wire, Beryllium And Vacuum Fittings:

Finally, I got some small bits and bobs.  Namely tungsten wire for the Fusor’s inner grid.  I bought 20m of 0.6mm diameter wire, which should be fine.  I also got 2g of beryllium metal for combining with americium to make an AmBe neutron source to test my neutron detection system against.  For now the Be is being kept locked up as it can have some nasty effects if not handled properly – safety is key.

Third, I bought a KF10/KF16 centering ring and a KF25 to KF16 reducer for joining my Pirani gauge to the vacuum line.  The Kwik-flange parts were both from mn-vac on Ebay, they have a lot of vacuum fittings available if anybody is looking for them, especially KF.  Last, but not least, I purchased a 5-way conflat cross from Ebay.  I was thinking of using it as a small test chamber until my larger vacuum chamber arrives, but the flange size is 3-3/8″ (DN50) and 3-3/8″ fittings aren’t very common used/at prices that I can’t afford, so I’ll probably end up connecting it to the larger chamber as an instrumentation flange.

Tungsten wire inner grid Fusor fusion Tom McCarthy vacuum

Tungsten wire for the inner grid.

Beryllium neutron source Fusor fusion Tom McCarthy detection

My 2g of Beryllium, hard to see, but being kept contained until I need to use it.


Vacuum parts line Fusor fusion Tom McCarthy kf kwik-flange

KF25 reducer and KF16/10 centering ring.


conflat cross vacuum chamber fittings Fusor fusion Tom McCarthy

5-way DN50 conflat cross.


That’s all for now,