Open rogerio-acioli opened 5 years ago
Hi Rogério,
You should expect about 0.4Hz of that to be coming from the cosmic ray muons. The remaining triggers are actually due to radiogenic backgrounds, like gamma and beta decays in the material around you. 200 counts in a minute is pretty high, but perhaps you are measuring in an environment that actually has a rather high background. The highest I’ve seen was in an apartment in Stockholm where I found about 2.5Hz.
The THRESHOLD value is the trigger value on the ADC (it is trustable to about 1%). It can be converted to a SiPM pulse amplitude using the calibration. If, say, you have better scintillator than us, the pulses will on average be higher and more will pass the trigger.
My best guess for a high count rate would have been from the black tape, but it sounds like you replaced it. You could try a couple of measurements to see if things are behaving well.
Thanks,
Spencer
On Oct 16, 2018, at 8:26 PM, rogerio-acioli notifications@github.com wrote:
Hi, Last week I finished the construction of my first detector. Everything looks fine, but the counts are very high. By using a THRESHOULD of 50 I'm finding something about 200 counts per minute. I had to use 220 of THRESHOULD to find the expected counting of 0,5 per minute
I already polish heated the scintillator, changed the screws for something with a smaller head and recovered the package with a better quality black tape. Anyway, the counts still high. I'm working with +29.7V at the HV pin.
Is that value of THRESHOULD trustable to work? I'm grateful for any help with that issue!
Att. Rogério.
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Hi, Spencer!
Thanks for the tips, before build another one detector, I'll try to make more measures in other places. When you say the best guess would have been the black tape, you think I should put more levels of tape? I put just two, one for each direction.
I'm using the average scintillator BC480, from Bicron, sell at eBay. The heat polish really makes a good difference!
Thanks for the tips, Rogério
Hi,
I don’t actually think you have a light leak, but you could try adding another layer. Normally, if there is a light-leak the detector will only register a single count and never reset to look for the subsequent pulses.
Thanks,
Spencer
On Oct 17, 2018, at 9:15 PM, rogerio-acioli notifications@github.com wrote:
Hi, Spencer!
Thanks for the tips, before build another one detector, I'll try to make more measures in other places. When you say the best guess would have been the black tape, you think I should put more levels of tape? I put just two, one for each direction.
I'm using the average scintillator BC480, from Bicron, sell at eBay. The heat polish really makes a good difference!
Thanks for the tips, Rogério
— You are receiving this because you commented. Reply to this email directly, view it on GitHub https://github.com/spenceraxani/CosmicWatch-Desktop-Muon-Detector-v2/issues/23#issuecomment-430851551, or mute the thread https://github.com/notifications/unsubscribe-auth/ABpeu9YCnEQEWrMyJI6JvVFw-v2NMsP-ks5ul-Q1gaJpZM4XjAcK.
Hi, Last week I finished the construction of my first detector. Everything looks fine, but the counts are very high. By using a THRESHOULD of 50 I'm finding something about 200 counts per minute. I had to use 220 of THRESHOULD to find the expected counting of 0,5 per minute
I already polish heated the scintillator, changed the screws for something with a smaller head and recovered the package with a better quality black tape. Anyway, the counts still high. I'm working with +29.7V at the HV pin.
Is that value of THRESHOULD trustable to work? I'm grateful for any help with that issue!
Att. Rogério.