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X-Rays in small microwave bulb?

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LAN_403

Polonium210

Fri Nov 11 2016, 12:50AM

Registered Member #3450 Joined: Sun Nov 28 2010, 05:01AM
Location:
Posts: 61

The bulb glows green on the inside when exposed to HV from an ignition coil. I only did this for a very brief moment to get the photo.
Also, I had my Ludlum model 3 survey meter which screamed when I turned the ignition coil on.
The meter was ~10ft away, I figured the electrical noise from the ignition coil may give a false reading..
Could this actually be producing X-Rays?
30905496655 3282e7c0cb B

woodchuck

Fri Nov 11 2016, 07:44PM

Registered Member #39190 Joined: Sat Oct 26 2013, 09:15AM
Location: Boise National Forest
Posts: 65

Kaye, in his book "X-Rays" describes an apple-green glow on the walls of soda-lime glass. Your pic seems to fit the description. The report of your Ludlum meter seems to buttress such a hypothesis. I'd say, yes!

johnf

Fri Nov 11 2016, 08:12PM

Registered Member #230 Joined: Tue Feb 21 2006, 08:01PM
Location: Gracefield lower Hutt
Posts: 284

No it will not be producing x-rays.
The glow is ionised argon gas in the bulb lighting up the glass.
Glass stops x-rays up to 20keV.
Your survey meter is better at picking up electrical noise than it is capable of responding to gamma /x-ray. remember its threshold is 35millivolt so any disturbance over this will be a count.

Physikfan

Fri Nov 11 2016, 08:13PM

Registered Member #60240 Joined: Mon May 16 2016, 07:01PM
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Posts: 304

Polonium210

You can check the existence of x-rays:

the simplest way is to put a lead or iron brick or at least a sheet of lead
between your bulb and the detection device.

Please do not change the distance between your source and the detector.

If you see a significant change of your "gamma" intensity, then you have really x-rays.
If there is no change your detector may probably receive the "electric noise" from
your pulsed high voltage source.

You should measure the voltage of your source, at least the maximum of the spark length
to calculate the possible energy of your x-rays.

hen918

Fri Nov 11 2016, 08:31PM

Registered Member #11591 Joined: Wed Mar 20 2013, 08:20PM
Location: UK
Posts: 556

I doubt there are x-rays; the gas in the tube will be preventing high enough acceleration of the electrons.

Polonium210

Sat Nov 12 2016, 01:13AM

Registered Member #3450 Joined: Sun Nov 28 2010, 05:01AM
Location:
Posts: 61

I did another test with the Ludlum meter still sitting ~10ft behind me.

Test 1 - No bulb in place to see if it is the electrical noise is the issue. The meter reads nothing but background levels.

Test 2 - Bulb in place and meter screams off the x1 scale.

With test 1 only the bulb was removed and nothing else.
I'm still not sure electrical noise is triggering the geiger counter...

Sulaiman

Sat Nov 12 2016, 09:29AM

Registered Member #162 Joined: Mon Feb 13 2006, 10:25AM
Location: United Kingdom
Posts: 3140

I agree that your detector could be picking up electrical noise
but I suspect x-rays,
ignition coils are rated for 25 - 35 kV and can produce more
crt tv tubes have had barium- or lead-loaded glass fronts since 10 kV b/w days because of x-ray hazards.

Maybe a digital camera with black tape or paper over the lens will show the x-rays, to settle the question ?

klugesmith

Sat Nov 12 2016, 03:10PM

Registered Member #2099 Joined: Wed Apr 29 2009, 12:22AM
Location: Los Altos, California
Posts: 1716

Yay for the scientific method. That last experiment was a good one. Another would be to run the whole apparatus inside a metal enclosure (garbage can?) as an RFI shield. See what the rad meter says. With an opening in the purported shield, do you get behavior consistent with streaming x-rays (scattered by air)?

Your pictures are reminiscent of a classic Amateur Scientist column in Scientific American, I think the July 1956 issue, "An Inexpensive x-ray machine".

found here:

That tube, or your bulb, could not be an argon-filled type. It would have to be evacuated but not very well evacuated.

You might be irradiating yourself.

Physikfan

Sat Nov 12 2016, 05:16PM

Registered Member #60240 Joined: Mon May 16 2016, 07:01PM
Location:
Posts: 304

Switch on your ignition coil with the bulb,
switch on your gamma detector, distance between them about 50 cm.
And then put a metal box or at least an aluminium sheet
between bulb and detector and watch the display of your detector.

Is there a significant change of the counts/second or not?

Polonium210

Sun Nov 13 2016, 03:28AM

Registered Member #3450 Joined: Sun Nov 28 2010, 05:01AM
Location:
Posts: 61

Klugesmith, Thank you for the link it was a good read.

I'm looking at getting some lead sheet before I continue...

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