AD-25-500 Russian alpha particle detector
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- Real name: Chris Mullins
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AD-25-500 Russian alpha particle detector
In my search for a Canberra PIPS detector, I ran across an ebay listing for AD-25-500 (PDF datasheet here: https://scintillators.ru/datasheet/Alph ... 25-500.pdf) for $250, or for $350 you also get a charge amplifier (the a-CSA: https://scintillators.ru/index_en_products.htm). There's even an online review of it: http://physicsopenlab.org/2018/10/08/al ... od-csa-sa/.
Has anyone run across this before? If it looks legit, I'll get one and try to use it with the Canberra 7401 acquired at the last HEAS, and/or the CSA they also sell.
Has anyone run across this before? If it looks legit, I'll get one and try to use it with the Canberra 7401 acquired at the last HEAS, and/or the CSA they also sell.
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- Posts: 68
- Joined: Sun Feb 19, 2017 11:32 am
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Re: AD-25-500 Russian alpha particle detector
Well, looks like no one's got any background on it. I'm going to get one, and I'll post any results here. Estimated delivery is January, so it will be a while ....
- Richard Hull
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Re: AD-25-500 Russian alpha particle detector
It looks like you will be the pioneer here. Let us know how it goes and what your results are with this unknown.
Richard Hull
Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Re: AD-25-500 Russian alpha particle detector
Well, it arrived (early actually). The ebay seller has been very responsive with some questions I had. I haven't had time to do anything serious with it yet, but I did hook the detector to the CSA/shaper board and fired it up. I taped the detector to a KF25 weld flange to make a small shielded "chamber" that I could place over a radioactive sample. For this quickie test I didn't put it under vacuum.
Alpha detector attached to KF25 flange, uranium ore in the background: CSA board and detector, with ground strap around KF16 flange, 50V bias from 9V batteries
Scope shot of pulse shaper (top yellow trace) and raw CSA output (bottom purple trace):
I was getting anywhere from 5-20 pulses per minute (no vacuum), depending on how close the uranium was to the detector. Next steps are to put the whole thing under vacuum, then run the output into the Theremino MCA system (https://www.theremino.com/en/downloads/radioactivity).
I have a couple of other radiation sources I can try too. Any other suggestions to fully test it?
Alpha detector attached to KF25 flange, uranium ore in the background: CSA board and detector, with ground strap around KF16 flange, 50V bias from 9V batteries
Scope shot of pulse shaper (top yellow trace) and raw CSA output (bottom purple trace):
I was getting anywhere from 5-20 pulses per minute (no vacuum), depending on how close the uranium was to the detector. Next steps are to put the whole thing under vacuum, then run the output into the Theremino MCA system (https://www.theremino.com/en/downloads/radioactivity).
I have a couple of other radiation sources I can try too. Any other suggestions to fully test it?
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- Joined: Sun Feb 19, 2017 11:32 am
- Real name: Chris Mullins
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Re: AD-25-500 Russian alpha particle detector
I made some more progress exploring the AD-25-500 detector. Now the detector is under vacuum, and to avoid noise problems, I put the entire CSA board in the chamber too. Only power, ground, detector bias, and pulse shaper output go outside the chamber.
CSA board (covered with black tape on both sides, to avoid shorts) on the bottom of the chamber, alpha detector mounted to top of KF25 flange over it): Entire system (roughing pump, chamber, MKS 901p to confirm vacuum):
I ran the CSA output into the mic input of my laptop (after attenuating with a 10K pot), and ran the Theremino MCA software, using a fresh Am241 sample. The Am241 (ex-smoke detector) is about 1 inch from the detector. With normal air pressure, the detector gave around 160 counts/minute, with average pulse height around 350 mV. Under 50-100 micron vacuum, I estimate around 55k counts/minute, 1.4V average pulse height. The Theremino software count was much less - it's missing a lot of the pulses, either due to sampling rate issues, the software itself not keeping up, or user error (likely).
The laptop mic input samples at 96 kHz, so it's not really adequate for these pulses. One A/D sample is about the same width as the pulse itself (~15 us). You can see the resulting shape in the Theremino window - it's basically the impulse response of the sound ADC system rather than the original pulse as seen in the scope trace in the last post. But the overall sampled height seems to be roughly proportional, so it's not 100% worthless.
Anyway, still playing around with it, and open to further suggestions! I may try to hotwire the detector into the 7401 NIM alpha spectrometer module I got from Richard at the last HEAS. I don't have a NIM crate to power it up, so I'd have to hotwire that too.
CSA board (covered with black tape on both sides, to avoid shorts) on the bottom of the chamber, alpha detector mounted to top of KF25 flange over it): Entire system (roughing pump, chamber, MKS 901p to confirm vacuum):
I ran the CSA output into the mic input of my laptop (after attenuating with a 10K pot), and ran the Theremino MCA software, using a fresh Am241 sample. The Am241 (ex-smoke detector) is about 1 inch from the detector. With normal air pressure, the detector gave around 160 counts/minute, with average pulse height around 350 mV. Under 50-100 micron vacuum, I estimate around 55k counts/minute, 1.4V average pulse height. The Theremino software count was much less - it's missing a lot of the pulses, either due to sampling rate issues, the software itself not keeping up, or user error (likely).
The laptop mic input samples at 96 kHz, so it's not really adequate for these pulses. One A/D sample is about the same width as the pulse itself (~15 us). You can see the resulting shape in the Theremino window - it's basically the impulse response of the sound ADC system rather than the original pulse as seen in the scope trace in the last post. But the overall sampled height seems to be roughly proportional, so it's not 100% worthless.
Anyway, still playing around with it, and open to further suggestions! I may try to hotwire the detector into the 7401 NIM alpha spectrometer module I got from Richard at the last HEAS. I don't have a NIM crate to power it up, so I'd have to hotwire that too.
- Richard Hull
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Re: AD-25-500 Russian alpha particle detector
Good work, Chris! Work arounds are key to adapting things and getting them to work. Keep up the good work and reporting.
Richard Hull
Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Re: AD-25-500 Russian alpha particle detector
This is an excellent project. Did you continue tinkering with this design in order to meet your needs?
I will be purchasing a micod kit myself for 209Po and 210Po detection. If you are no longer using your set, I would purchase yours at cost.
Cheers,
Evan
I will be purchasing a micod kit myself for 209Po and 210Po detection. If you are no longer using your set, I would purchase yours at cost.
Cheers,
Evan
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- Posts: 68
- Joined: Sun Feb 19, 2017 11:32 am
- Real name: Chris Mullins
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Re: AD-25-500 Russian alpha particle detector
I haven't gotten much further in the last 5 years. This is part of a much larger personal project to achieve detectable p-B11 fusion, detectable by using two PIPS detectors and coincidence detection to confirm the correct total particle energy. This is looking more like a post-retirement project, so it may be a while longer ....
In any case, I'm still hanging on to the gear. Those alpha detectors haven't been on ebay for some time, and I'm not aware of any other low cost options, except for true DIY projects like this: https://scoollab.web.cern.ch/diy-particle-detector
In any case, I'm still hanging on to the gear. Those alpha detectors haven't been on ebay for some time, and I'm not aware of any other low cost options, except for true DIY projects like this: https://scoollab.web.cern.ch/diy-particle-detector
Re: AD-25-500 Russian alpha particle detector
Thanks, Chris. What a cool project. I am getting in touch with scintillators.ru now.
There is shockingly little metadata on these detectors. Do you know any details on the detector or signal amplification hardware? Is it a PIPS chip, or something different? Did you get additional info from the manufacturer upon purchase, or is it still a bit of a black box?
Cheers
Evan
There is shockingly little metadata on these detectors. Do you know any details on the detector or signal amplification hardware? Is it a PIPS chip, or something different? Did you get additional info from the manufacturer upon purchase, or is it still a bit of a black box?
Cheers
Evan