Collection of information about russian SNM tubes

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Lukas Springer
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Re: Collection of information about russian SNM tubes

Post by Lukas Springer »

Which just goes to show how easy to use those tubes are :)

No window comparator needed, no fine tuning, just a comparator with some hysteresis and done!

I've got a question for you, steven:
You spec your GS-NEUTRON-150 as 15% efficiency, is that with the moderator in a fast neutron field or just a spec for the tube and thermal neutrons?

Lukas
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Steven Sesselmann
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Re: Collection of information about russian SNM tubes

Post by Steven Sesselmann »

Lukas,

As you know the specs are all in Russian and if I recall correctly only lists background or self count.

My estimate for the efficiency of the SNM-12 tube is based on some tests I did at the University of Sydney with an AmBe neutron source said to emit around 2x10^6. Tests were done with a 90 mm cylindrical HDPE moderator at various distances and based on the source activity we worked out the efficiency of the tube to be around 0.15 nvth.

This also agrees roughly with the background counts we get from these tubes.
Which just goes to show how easy to use those tubes are :)
I would go as far as calling these tubes "easy to work with". If you don't have a decent oscilloscope you probably think they are damaged or not working. Signal is noisy and background counts are far and few between... blink and you miss it! But if you know what you are looking for and have a fast scope with a trigger set correctly you will catch a neutron every 10 -15 minutes.

Make sure to run these tubes with a high load resistance 50 Mohm or more.

Steven
http://www.gammaspectacular.com - Gamma Spectrometry Systems
https://www.researchgate.net/profile/Steven_Sesselmann - Various papers and patents on RG
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Richard Hull
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Re: Collection of information about russian SNM tubes

Post by Richard Hull »

The key expression is "once you get the hang of it" or "if you have a fast oscilloscope". All good, honest and wise observations. I continue to applaud all those here who are willing to help in the effort based around what I term, "The Russian neutron tube dilemma". That is an effort to make these rather inexpensive and available tubes do "good service" as advertised in their name...."Neutron detector". Any good nuclear metrologist realizes that neutron measurement is tricky, at best, and deception can be the order of the day without plus-ultra instrumentation and a person who knows how to use it in the environment the measurement is taken.

A keen observer here at fusor.net will come to understand that there are but a tiny few here who are willing to learn to get the "hang" of anything! There are even fewer with a fast o'scope. Having both a person so equipped and willing to struggle to get the "hang" and the fabulous rewards associated with the struggle, be it difficult or relatively easy, is a great rarity here. Yes, there will always be a few of us. We will teach and hopefully we will help to get others used to "getting the hang" of how to bring hardware to the point of doing what is claimed or expected of it.

For many here, hooking up a 555 timer is beyond the scope of their background. Pumping variable high voltages into a biased nuclear detector, be it proportional, corona or gas amplification based, is a mystery and, often, a bridge too far for the vast majority here. Recognizing that others are knowledge and "kit" limited is often very tough and the word "easy", used by the most advanced here, can be all too readily applied.

My old saw of "Nuclear fusion is easy to do" is very much correct, but misleading. Compared to any other fusion process on the planet, it is abysmally easy to do if you look at and compare costs and complexity to achieve easily detectable nuclear fusion producing millions of fusions per second.

Still, all those of us who can "do", and are equipped to "do", create and work on evolving, useful, posts like this one. For those capable few, the Russian tubes are an option, yet the rules for claiming fusion remain moderately biased against them. Thus, we are requiring extra evidence that a Russian tube based counter is really working as a neutron detector. Unfortunately, it is all too easy to have it function as a GM counter or, more likely, a noise detector, if you don't have the "knack" or have gotten the "hang" of how to bias and discriminate the other radiations or noise out of the picture.

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
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Steven Sesselmann
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Re: Collection of information about russian SNM tubes

Post by Steven Sesselmann »

Lukas Springer wrote: Thu Feb 28, 2019 4:58 am
I've got a question for you, steven:
You spec your GS-NEUTRON-150 as 15% efficiency, is that with the moderator in a fast neutron field or just a spec for the tube and thermal neutrons?

Lukas
Lucas,

I have an update on the efficiency numbers for the SNM-12. I built a GS-NEUTRON for a client and had it calibrated by ANSTO here in Australia and the average efficiency over a radius of 0.4 to 2.2 meters came in at an nvth of ~ 0.395 this is about 250% more efficient that I initially calculated based on measurements at the University of Sydney.

Send me a PM if you want a copy of the calibration certificate

Steven
http://www.gammaspectacular.com - Gamma Spectrometry Systems
https://www.researchgate.net/profile/Steven_Sesselmann - Various papers and patents on RG
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Michael Kaufmann
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Re: Collection of information about russian SNM tubes

Post by Michael Kaufmann »

Lukas Springer wrote: Tue Oct 16, 2018 4:32 am If you have any further information about any of the SNM tubes feel free to add it here!

about sensitivity of a soviet CHM tubes:


Image


so for CHM-18 it's like 50 counts per n*cm^2*sec if i understand correctly?
I can't say anything about my tubes sensitivity, but 4.6 Bar 3He are 4.6 Bar 3He.
are your tube brand new, or more like 30 years old? if the latter - don't you think you would be lucky to have as much as 2 bar in there probably? : )

i can't post images yet, but i have more data - like gamma rejection levels for example.
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Richard Hull
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Re: Collection of information about russian SNM tubes

Post by Richard Hull »

I agree that what info is to be found and shared regarding these corona tubes, is best placed as a reply to this thread. Sadly, all the circuit diagrams and other submitted images appears to be lost forever during our ill fated move to Go Daddy a couple of years ago.

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
John Futter
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Re: Collection of information about russian SNM tubes

Post by John Futter »

Richard
Why do you answer these trolls who cannot abide by the rules??
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Richard Hull
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Re: Collection of information about russian SNM tubes

Post by Richard Hull »

If information is exchanged, data provided and on point, with no attempt to foul the thread in a negative way or to advertise a product, I will answer. I did not look at the fact this was a first positing with no real name. It is indeed sad that so many posts here for the first time are submitted by those not following the simple sign up rules. You keep poking them for this failure and I'll continue to lock out the trash. I tend to not focus on the names or number of postings if the submission is sound.

I will again note to the poster, if still here, that we do not use block quotes as he did in our replies in a thread!

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
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Michael Kaufmann
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Re: Collection of information about russian SNM tubes

Post by Michael Kaufmann »

hi Richard.
I fixed the problem with the name, tho not with the first post (will do it soon). i came here from the pupman tesla coil mailing list - there were not so many restrictions : )
what are "block quotes" - aren't my two quotes the same as Steven Sesselmann's on this page?

p.s.
how much posts i need to be able attach pictures from datasheets for example?
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Dennis P Brown
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Re: Collection of information about russian SNM tubes

Post by Dennis P Brown »

First off, our rules are so simple and limited that it is really amazing people consider them intrusive or even an issue (from day one, before it was a rule, I only used my full name); however, do understand we are a formal site that strives for exchange of scientific and technical information. As such, being professional is not optional unlike so many other sites. That said, we all error from time to time - I certainly have/do. But for a first post you, unfortunately, hit the trifecta. No big deal. You've fixed the most important issues and in the future, just avoid block quotes. I.e. creating large boxes containing previous statements by other people. This eats up storage for saved posts/threads.

Second and most importantly, we try to show by our posts that we are professional and treat this site like the useful forum it has become. Glad you have decide to join and don't worry too much about what occurred previously - just continue and do help to make this a great site for fusor work.
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Richard Hull
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Re: Collection of information about russian SNM tubes

Post by Richard Hull »

In response to your question....Are not my quotes those from Steven Sesselmann's on this same page?....In response... Yes, they are his exact words and they are absolutely unnecessary. We have already read those words of his above and need not be reminded of them. We are smart readers and need not be reminded of the exact words in any preceding posts. Block quotes are any verbiage in your current post that is in shaded gray "block" which quotes from another post within any given entire thread. We do not like block quotes in gray in responses. Your responses in your posts should be all your own words.

The above request is commonly noted to new folks here. Avoid block quotes from previous posts in a thread.

To my knowledge there is no restrictions on posting images of any sort on new people. To the contrary it is highly recommended. A picture is worth a thousand words. Your table of official, published efficiencies was most welcomed.

Note: Block quotes are OK if you are referring to some quote made way back in a thread of some months or years ago. Do not use them in response to a recent running thread

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
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Michael Kaufmann
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Re: Collection of information about russian SNM tubes

Post by Michael Kaufmann »

shall we continue? : )

bias voltage selection:

подбор режима питания.png

absolute maximum sensitivity (counts*cm^2/n) of counters to neutrons of various spectra:

чувствительность.png
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Dennis P Brown
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Re: Collection of information about russian SNM tubes

Post by Dennis P Brown »

Nice graphs but any chance we can get some translation into English on the key points (graph parameters.) Maybe a bit on the context of the articles - I see it is a voltage vs. some type of response for each detector type.
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Richard Hull
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Re: Collection of information about russian SNM tubes

Post by Richard Hull »

The RS-P4 and P7 references in the graphs and table are comparison to the famous industry standard Reuter and Stokes P4 (4ATM 3He) and P7 (7ATM 3He) proportional detector tubes to the Russian tubes. I have since 2004 only used the RS-P4, 21-inch long tube in my neutron detection system.

Richard Hull
Attachments
3He - BF3.Anno.jpg
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
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Joe Gayo
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Re: Collection of information about russian SNM tubes

Post by Joe Gayo »

@Michael

Can we get the entire document? I would like to translate.

Thanks
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Michael Kaufmann
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Re: Collection of information about russian SNM tubes

Post by Michael Kaufmann »

yea, sure - you can download it from The International Atomic Energy Agency website.
sorry guys - don't have much free time now to translate this on my own.
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