Jan Ruge Fusion Attempt @ Chaos Darmstadt
Posted: Fri Dec 01, 2017 9:39 pm
Heyho,
First of all, as I'm quite new here, pleas let me know if this is the wrong section
This is a brief introduction to my Fusor project or static neutron source to be precise (shooting deuterium ions on a metal plate).
I try to keep this up to date as we make any progress.
The vacuum system is based on an oil diffusion pump, I picked up on Ebay a couple of years ago, a TV-203 to be precise.
I ended up building a compact module with all the necessary parts to run the pump, as water cooling system a KF-40 inlet flange and an additional transformer to power up filaments for example.
The inlent flange was the main problem with that design as the pump should originally be mounted to a flat surface, what was a problem as I want to use the cheap standard KF vacuum fittings.
I managed to connect a ISO-F/KF40 adapter, that had aprox the right size using some metal parts, proper clamps, an O ring and some grease.
The first picture shows the first run of the diffusion pump creating a good vacuum as tons of xrays are generated, the second one shows the final version of the setup.
The current high voltage supply is a flyback transformer with a ZVS driver with a voltage multiplier which is encapsulated in epoxy to avoid corona discharge.
In the end this seems to be a bad idea, as after the epoxy cured, the glass started to crack.
The cascade worked for a couple of years, but now there is some arcing on one of the hv feedthroughs for the AC.
This problem might be fixable, but on the long term I need to build a new one.
The ion gun is mostly based on an anode ray tube, a glass tube that allow a gas discharge with a small channel to let the ions pass.
First, I tried to tighten the assembly using vacuum grease and rubber o-rings, but there was too much air leaking inside (I was not that accurate in drilling the holes) so I ended up fixing the problem using epoxy.
There is a small needle valve as used in CO2 applications for the gas inlet.
The following tests looked very promising as the ion ray were clearly visible, even though the vacuum was not ideal.
I was not able to open the needle valve even a bit, as there were too much air leaking inside the assembly.
This was most likely due to dirty seals, but we are currently debugging that problem.
The pre acceleration voltage for the ion gun was generated by using a cheap 'High Voltage Taser Module' for tasers.
It turned out that this module has one output grounded what can be problematic depending on the configuration (a friend was zapped a couple of times and the lab power supply went crazy).
This problem was fixed by using the built in transformer that has no reference to ground.
By applying a the acceleration voltage, there was a strong gas discharge what is not useful for that design as it slows down the ions and introduce much current.
Even though that was not intended, but this also seems to be a good sputtering device, so the inner of the glass tube was quickly plated with copper an zink during the tests.
First of all, as I'm quite new here, pleas let me know if this is the wrong section
This is a brief introduction to my Fusor project or static neutron source to be precise (shooting deuterium ions on a metal plate).
I try to keep this up to date as we make any progress.
The vacuum system is based on an oil diffusion pump, I picked up on Ebay a couple of years ago, a TV-203 to be precise.
I ended up building a compact module with all the necessary parts to run the pump, as water cooling system a KF-40 inlet flange and an additional transformer to power up filaments for example.
The inlent flange was the main problem with that design as the pump should originally be mounted to a flat surface, what was a problem as I want to use the cheap standard KF vacuum fittings.
I managed to connect a ISO-F/KF40 adapter, that had aprox the right size using some metal parts, proper clamps, an O ring and some grease.
The first picture shows the first run of the diffusion pump creating a good vacuum as tons of xrays are generated, the second one shows the final version of the setup.
The current high voltage supply is a flyback transformer with a ZVS driver with a voltage multiplier which is encapsulated in epoxy to avoid corona discharge.
In the end this seems to be a bad idea, as after the epoxy cured, the glass started to crack.
The cascade worked for a couple of years, but now there is some arcing on one of the hv feedthroughs for the AC.
This problem might be fixable, but on the long term I need to build a new one.
The ion gun is mostly based on an anode ray tube, a glass tube that allow a gas discharge with a small channel to let the ions pass.
First, I tried to tighten the assembly using vacuum grease and rubber o-rings, but there was too much air leaking inside (I was not that accurate in drilling the holes) so I ended up fixing the problem using epoxy.
There is a small needle valve as used in CO2 applications for the gas inlet.
The following tests looked very promising as the ion ray were clearly visible, even though the vacuum was not ideal.
I was not able to open the needle valve even a bit, as there were too much air leaking inside the assembly.
This was most likely due to dirty seals, but we are currently debugging that problem.
The pre acceleration voltage for the ion gun was generated by using a cheap 'High Voltage Taser Module' for tasers.
It turned out that this module has one output grounded what can be problematic depending on the configuration (a friend was zapped a couple of times and the lab power supply went crazy).
This problem was fixed by using the built in transformer that has no reference to ground.
By applying a the acceleration voltage, there was a strong gas discharge what is not useful for that design as it slows down the ions and introduce much current.
Even though that was not intended, but this also seems to be a good sputtering device, so the inner of the glass tube was quickly plated with copper an zink during the tests.