Spark Chambers

[Doodlebug]

I thought about pressure build up in the chamber as sparking will warm up the Argon gas
and so pressure build up.

To keep an eye on this in a very cheap way I will fit a thin sheet of neoprene
onto a 60mm dia neoprene flat washer.  This will be fitted to the top
acrylic plate with a small hole drilled through it.

In this way any pressure increase or decrease will immediately show as a
depression or bulge in the neoprene. (dotted lines)
It will be interesting to watch this as sparking occurs.
I may put a position sensor on it too.

So I can keep an eye on pressure and cut the HV if too much.

   

[Doodlebug]

When a partical passing through my chamber ionises the Argon, ( I hope ),
the spark created will continue so I need to cut the HV after some
short time. As I am finding, switching 20kV plus HV is rather costly so I will make a short period timer to cut the mains supply to the NST, if I can
detect when a spark has been triggered by a partical and not spurious.


This is all a new ball game for me and the next part of the game is ordering
a small cylinder of Argon and a regulator.
to suit. I think these will fit the bill from Machine Mart who is near to me...……..

https://www.machinemart.co.uk/p/argon-gas-cylinder


https://www.machinemart.co.uk/p/bott...RoC6RQQAvD_BwE

Maybe I ought to train up as a gas engineer.

[Ed_Dinning]

Hi, in tube type ionisation detectors, that are not meant to spark over, CO2 is often added as a quench gas to give short pulse times. Other gas mixtures were used.
The drawback with CO2 is that it deposits gunge on the central wire and increases its diameter, reducing tube sensitivity.

Ed

[Doodlebug]

Thanks Ed for that, but not keen on mixing gases with
complications of two cylinders and gas connections.

I think, for my simple design, cutting the HV will
be the way to go to quench the sparks.

But until I see exactly what the rig produces
I cannot finalise anything.