Fusor Forums

Mu-metal is not yet installed, this is a bare tube.

All mu metal I've ever owned has been pillaged from scrapped CRT's. But Ebay probably has all you need.

You're in for the slightly soul crushing experience of making a really beautiful looking instrument and then completely destroying its aesthetics by flooding it with black tape!

I've just been there!

This looks like a buck standard bialkali pmt. I suspect it will do just fine. As long as the spectral response isnt wierd. Scintillation counting is a very forgiving setup, pmt wise. The only admitted light is the scintillation light (if you light proof properly!), and they're operated at positive h...

Oh I'm sure you're right, and I'm very grateful for the help! I will try adding in the preamp and see if there is a difference. Perhaps the 3.6n is too large a coupling cap as well. The wrong polarity of my pulses could be my scope being too slow to see the original negative component, leaving only ...

I don't think that's right. There's no voltage drop over the anode resistor, it's purely a current limiting thing. One can also ground it, and take the inverted signal from the last dynode. http://winspa.de/help101/images/Channeltron.jpg http://winspa.de/help101/hardware.htm Here's an example of a b...

For bias a meg seems pretty standard for electron multipliers, but I could be mistaken. Here's an article featuring a neg bias VEU-6 for positive ion detection, and to me it looks like they terminate the output directly in 50 ohm, and get 100-200 mV pulses out. http://www.mathnet.ru/links/da376d7812...

I just realized something strange is going on - Why are my output pulses positive?! I've set up the channeltron for negative ions/electrons, and with signal tapped from the anode. See below for an actual schematic of my setup. If electrons collect on the anode, then the bias should momentarily drop,...

That's more or less exactly the dekatron scaler I was thinking of! Yeah, having one of those in a NIM bin world fill the entire bin! I think fundamentally, if displays and readouts were needed as human friendly readouts, they were important enough instruments that they would have their own rack unit...

These strange scaler displays are really a treasure of display technology - and a horror from a human interface device point of view! The earliest scalers from the 1940s used the cyclic dekatron tubes, which are also bizzarely beautiful. Even into the standardization of 7segment LED displays, the hu...

Oh and some imagery