Search found 662 matches

by Steven Sesselmann
15 Jun 2015, 07:08
Forum: Spectrum
Topic: XRF Gold Assay Experiment
Replies: 16
Views: 7205

Re: XRF Gold Assay Experiment

Geoff, That was my first thought as well, but the x-rays from silica are nowhere near 45 keV. As mentioned above the two peaks produced sum to approx. 60 keV which makes me suspect it is the 59 keV gamma from Am which is scattering at two different angles to produce these peaks, Here is a good resou...
by Steven Sesselmann
14 Jun 2015, 08:54
Forum: General discussion
Topic: Cosmic radiation
Replies: 15
Views: 7459

Re: Cosmic radiation

Thanks for posting the NaI comparison. I tried to capture the same on my 3" here, but so far no luck. My OWON oscilloscope does not have the function to capture a second pulse automatically, I have to capture one by one and reset the scope each time a big pulse occurs.
by Steven Sesselmann
12 Jun 2015, 14:12
Forum: Detectors
Topic: XR-100CR Si-PIN X-Ray Detector + PRA
Replies: 7
Views: 5519

Re: XR-100CR Si-PIN X-Ray Detector + PRA

Very nice resolution, this post inspired my to pull out an old project with a PIN diode detector from FirstSensor, but once again the project defeated me, I just can't seem to get any kind of signal from the detector, even when building the amplifier circuit according to the manufacturers diagram. S...
by Steven Sesselmann
12 Jun 2015, 13:27
Forum: Spectrum
Topic: Coincident spectra from Compton scattering Cs-137
Replies: 18
Views: 8143

Re: Coincident spectra from Compton scattering Cs-137

Tom,

I moved your post to the original thread, also could you please explain what we are looking at in the above coincidence plots. Most of us are not used to seeing spectra this way. Tell us how you got the raw data and what software you used to plot it.
by Steven Sesselmann
11 Jun 2015, 20:37
Forum: Introductions >> Start Here !
Topic: New Member
Replies: 2
Views: 1581

Re: New Member

Thanks for the brief introduction. You have certainly found others with similar interests, but please observe the forum guidelines about posting with your real name. You can put your name in the signature, which saves you signing each post.
by Steven Sesselmann
11 Jun 2015, 10:22
Forum: General discussion
Topic: Cosmic radiation
Replies: 15
Views: 7459

Re: Cosmic radiation

That's very cool...

I have been trying to repeat this with my 3" NaI(Tl) detector, but have not been lucky enough to see a doublet yet.

Must see if my scope can be set to trigger for doublets only. What scale are you looking at, is it 20 mV divisions on the Y axis and 1 µs on the X axis?
by Steven Sesselmann
09 Jun 2015, 08:21
Forum: Spectrum
Topic: XRF Gold Assay Experiment
Replies: 16
Views: 7205

Re: XRF Gold Assay Experiment

Here are a few more spectra... This one is from an Australian Dollar coin. The alloy is Cu, Ni, Al dollar.png This is a spectrum of pure Indium... Indium(2).png This is a spectrum of a river pebble and I have no idea what it contains or why it emits these peaks. pebbles.png Drinking Glass drinking g...
by Steven Sesselmann
09 Jun 2015, 08:12
Forum: Spectrum
Topic: Coincident spectra from Compton scattering Cs-137
Replies: 18
Views: 8143

Re: Coincident spectra from Compton scattering Cs-137

Tom, I think we all agree that it's not a problem, instead it looks as if two low resolution detectors can be used in this way to resolve an energy peak to a degree otherwise not possible. If the energy deposited in each detector is a function of the scattering angle, then it should be possible to c...
by Steven Sesselmann
08 Jun 2015, 17:43
Forum: Spectrum
Topic: XRF Gold Assay Experiment
Replies: 16
Views: 7205

Re: XRF Gold Assay Experiment

Today I made myself a new shield for my new XRF detector. On the attached images you will se I used a small iron pot to melt some lead, which I cast into an old 65 mm aluminium detector housing. I them machined it to fit over my 1.5" XRF detector, drilled a 10 mm hole in the middle, and embedded thr...
by Steven Sesselmann
08 Jun 2015, 16:36
Forum: Spectrum
Topic: Coincident spectra from Compton scattering Cs-137
Replies: 18
Views: 8143

Re: Coincident spectra from Compton scattering Cs-137

pietkuip wrote:Your summary is completely correct. I do not quite understand what puzzling part remains?
It's all about asking the right question, and as I was formulating my question for you, I ended up partially answering my own question.

Nice experiment, well done Tom and Pieter.