Fusor Forums

A few months back, I bought a Russian counter tube on Ebay, purported to be a Neutron Detector of some sort. Now I am not quite so sure. The package identifies it as a "counter tube", and nothing else, and the part number translates out to SI13N. No data sheet came with it, and I haven't been able to find any data on the web so far. Attached is a picture of the tube and package. The tube is hand-labeled with the part number, date code (1990, I think), and "N530" and "Vd = 16.79". This may be a boron-lined tube, and the large diameter would yield more surface area for an inner boron coating to increase sensitivity. Then again, it may be a fat GM tube. Any guesses? Even better, does some one here have a list of Russian detector tube types that include this one? I didn't pay a whole lot for the tube, so it's no real disaster if it's just a GM. Even in that case, it would be nice to have an idea of the operating voltage.

Hi Richard,

The Scientific Research Institute for Technical Physics and Automation (VNIITFA) is a manufacturer of this tube:

http://www.vniitfa.ru/index.php?option= ... 8&Itemid=1

It is described as a high-efficiency He-3 counter with applications in "geophysics, nuclear physics, radiation control systems, and nuclear power."

Although the SI13N is among the tubes described thusly, the example data table in their catalog doesn't list specs for that particular part number. A similar number in the data table is the SI19N, which is 32mm in diameter, 218mm long, has a "corona ignition voltage" of 1750V and a working voltage of 2400V, and an efficiency to thermal neutrons of 70%. With any luck, yours is just shorter but has the same fill gas and voltage characteristics. Just to clarify that this is probably a corona counter, some of the other tubes in the table are explicitly defined to work in the "proportional mode," but this is not one of those.

Good luck!

-Carl

Thanks for the link - I think I'll have one of my Russian colleagues at work hang over my shoulder and translate some of the links, as I'd like to email the makers about the tube. If it has He3 fill, (even if it is a corona tube), I practically stole it given the price I paid.

Corona neutron counter СИ-13Н (СИ13Н, СИ-13-Н, СИ 13 Н, СИ 13Н)

Corona neutron counter SI-13H high-performance in geophysics, nuclear physics and control
systems, control and protection of nuclear reactors.

Technical characteristics of the devices crown neutron counters СИ-13H:

Nominal operating voltage range - 2000V-2800V;
Minimal Voltage СИ-13H (start counting at) - 1600V-1750V;
Length of the counting plateau (characteristics) curve - not less than 800V;
The slope of the plateau (СИ-13H) - no more than 0.02% / V-1;
Own background - no more than 0,083 s -1;
Background (mean) corona discharge current - not more than 15.0 uA.

Thank you - that's enough information to get started.

You might find some of the threads here useful as well.
http://www.coultersmithing.com/forums/v ... m.php?f=11
We've gotten several new old stock Russian corona tubes of various types and gotten all of them working pretty well.
They tend to be a little bit noisy, and sometimes false count for awhile before settling down when power is applied. But they work fine other than that, and are real nice at the price...