RF enhanced ion source

For the design and construction details of ion guns, necessary for more advanced designs and lower vacuums.
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Rapp Instruments
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Real name: Thomas Rapp
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RF enhanced ion source

Post by Rapp Instruments » Thu Sep 04, 2014 9:25 pm

Hello,
I have build a small rf-generator to enhance the ion output of my channel ray source in the small neutron source.
The generator use a old line deflection power tube PL36 in hartley oscillator circuit. The anode voltage is about 700V, the frequency 60 MHz and the estimated power about 30..40W.
Image
Image Image
With working oscillator the target beam current increased from 30µA to 100 µA.
The left side electrode of the ion tube at 20kV potential >> 30µA
The oscillator alone, nice plasma but no target current >> 0 µA
Oscillator and 20 kV on electrode >> 100µA

Thomas

Gleedaniel Martin
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Real name: Gleedaniel Martin
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Re: RF enhanced ion source

Post by Gleedaniel Martin » Thu Mar 26, 2015 9:14 am

Well created and designed. I salute for the innovation and creativity of your mind.

ian_krase
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Real name: Ian Krase

Re: RF enhanced ion source

Post by ian_krase » Thu Oct 19, 2017 6:19 am

Can one run something like this safely without needing to worry about causing radio interference?

John Futter
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Re: RF enhanced ion source

Post by John Futter » Thu Oct 19, 2017 9:42 am

Ian
This is an inductively coupled plasma (ICP)
there are specific bands (ISM)reserved for this type of equipment
11- 26 MHz for HF 433 915Mhz for VHF UHF 2440 etc for microwave
upshot is yes they radiate alittle but they only interfere with other ISM equipment
Thomas has done an excellent job
most accelerators use a CCP or capacitively coupled plasma as sometimes you have to play with parametres to get the icp running , the CCP tends to start easily compared the ICP

Jerry Biehler
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Re: RF enhanced ion source

Post by Jerry Biehler » Thu Oct 19, 2017 10:18 pm

450khz, 2mhz, and 4mhz are other options. I wonder if you could use one of the power supplies intended for inductive lighting.

https://www.inductionlightingfixtures.c ... xoQAvD_BwE

Silviu Tamasdan
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Re: RF enhanced ion source

Post by Silviu Tamasdan » Sat Oct 21, 2017 1:45 am

Probably the easiest modification would be to decrease the frequency to 40.68MHz, which is the closest ISM. Next one down would be 27.12MHz, next one up 915MHz ( both in ITU region 2, i.e. the Americas, and in ITU region 1=Europe)
There _is_ madness to my method.

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