alpha particles

[thermonub]

hey

I need a good way to detect alpha particles without using a gieger counter. i know that zinc sulfide will sparkle slightly when hit with alpha particles but does it need to be "activated" or can i use the zinc sulfide i get from burning zinc and sulfur together.

 

thanks for your time.

[swansont]

It's possible to make a homemade cloud chamber.

[thermonub]

would some amercium from a smoke detecter be a usable radiation source?

[swansont]

Probably. You need to be aware of the risks involved with playing with radioactive sources, though.

[John Cuthber]

Just for the record, while it may be a usable source, it may not be a legal one.

Anyway to answer the original question, no. Sorry but you need carefully processed and doped ZnS to get a decent effect.

I have seen the light from a beta source irradiating a bit of the phosphor covered inside of a broken fluorescent tube, but I can't say I recommend this experiment.

[thermonub]

"Anyway to answer the original question, no. Sorry but you need carefully processed and doped ZnS to get a decent effect"

 

Rats!

I heard somewhere about taking smoke detectors aprt being illegal but i hope no body's going to tell anyone:D

[John Cuthber]

It's OK, nobody ever looks at stuff posted on the net. You are just as safe as the person who posted about getting away with murder.

[YT2095]

IIRC Sodium Iodide will work also.

as for Zinc Sulphide I beleive it needs to be doped with Copper in order to work.

I`ve never had any luck with Am241 as a source for visible light effects in this way, although my Thorium Chloride works reasonably well, you still need a dark room and time for your eyes to adjust though.

[John Cuthber]

If this

http://www.detectors.saint-gobain.com/Media/Documents/S0000000000000001004/SGC_SodiumIodideDataSheet_1005.pdf

is typical (and I think it is) then the problem with NaI is that it emits lighht at about 415nm, that's only just visible so the eye won't be very sensitive to it. Even to get that you need to dope the NaI with thalium and that's not stuff you want to play with.

[anthonyj]

Hi thermonub,

 

I hope you don’t mind me adding to your thread with a request for some help too, as I am trying to do the same thing, here is where I am:-

 

I’m using Am241 (33Kbq) from a smoke detector as a source .

I believe you can get very good results from pointing the source at a CCD camera that has the lens removed, loads of blips can be seen and I believe these are individual Alpha particles hitting the elements, the only thing is that the particles eventually destroy the elements and you are left with a continuously speckled picture that I guess over time would become completely white.

I have tried pointing the source at a CCD with the lens on and you can see the low energy gamma rays causing the odd blip (well I assume that’s what they are).

Next I tried causing SEU’s (single event upsets) in SRAM, it just means causing errors, a 0 at a location on the chip flips to a 1 or vice versa its typically non destructive, the thing was though that I could not burrow down close enough to the silicone without damaging the chip to the point that it would not work at all. I am still looking for an Sram with the die exposed, I don’t think I am going to have any luck there though…..

Next I tried removing the lens from photodiodes to see if I could detect anything there, still working on that, the voltages are so low that noise becomes a big problem though. I looked at scintillators but thought getting the material might be tricky.

I then looked into ion chambers, you can make some nice low voltage ones that can be used as a pretty accurate measurement device, check out DIY ones here…

http://www.techlib.com/science/ion.html

because of capacitive effects of the wires you don’t get any nice blips like the G/M tubes just an over all measurement, but if that’s all you are after then fine.

I want to find a way of capturing discrete events or groups of events so the Ion chamber may not be the way to go for me.

I still think the Sram may be the way to go, the errors are nice and discrete and already in a digital form… yummy.

 

Any ideas anyone?