The results would be more meaningful if you had two identical tubes in separate cans, stacked on top of each other. Then you take the outputs and run them in to "Schmidt triggers" (for precise edge triggering on the event) and in to a logical AND gate (two integrated circuits would do it). If a muon event passes through both detectors from the same direction there will be a coincidence in each detector can and an indication that the event is coming from above. You could separate the two detectors to make the muon path much narrower but you might end up needing to create a coaxial cable delay line to offset the speed of light in the two detectors. Otherwise you would see two separate pulses that are only a few nSec apart. But the PMT's and scintillators should have enough persistence (afterglow) to overcome that effect. You would use integrated circuits like the 74HC series devices that are very fast. If you wrapped the two detectors in lead and put lead beneath the array you could further reduce the impact of gamma rays.
Hi!Thank's for your hints. I've done that coincidence measurements with 3 geiger tubes to detect cosmic muons. Take a look at it. Greetings from Austria, stopperl th-cam.com/video/fF170T0rB1U/w-d-xo.html
@@analogplanet9675 That will reduce the rate a lot. The cross sectional area of a typical GM tube is so small that the probability that a muon passes through the water tank also striking the GM tube is pretty low. Two PMTs in coincidence is the standard way to go.
Hello, is there any way to contact you? I am planning on doing a similar project for a college course but the technicians at my Uni have limited knowledge on PMT's. I'd like to know if it's possible to connect the raw output of the signal generated by a PMT to an oscilloscope (no pulse processing) and what equipment or circuits are needed to do it. For example, is there a simple adapter that exists for the PMT with BNC connectors that I can connect to a HV power supply and the output I can just connect to an oscilloscope? I saw a post where someone uses a T-splitter I think to acquire the signal but is that necessary?
by using distilled water you minimize interference to a respectable degree by having purer water. I'm not sure about ruling out radioactive traces in the water though, not entirely sure what you mean by radioactive traces. Do you mean radioactive decay of constituent water particles releasing photons and interfering?
Is the hertz rate of the electricity too slow to catch strikes? Or is it DC? How can you rule out background radiation? or is THIS background radiation? I'm a novice at this...
Muons represent a significant amount of ionizing background radiation, as I understand it something like 50%. In terms of hertz rate and stuff like that, I believe you can minimize it by sending the data to a computer and analyzing with computer software to, for example. minimize the x axis around the spike in order to make it easier to analyze. Generally speaking tho, any spike with the suddenness and amplitude of the one shown in the video on the screen will be associated with an actual detected photon (released as Cherenkov radiation from the muon interacting with water particles) which almost certainly comes from a muon.
Here's my thread concerning experiments with photomultiplier: forum.mosfetkiller.de/download/file.php?id=13960&mode=viewforum.mosfetkiller.de/viewtopic.php?f=6&t=61526&start=60
Fantastic! I hope to perform a similar experiment as well. Cerenkov light can be produced in air as well as in water. I do not know if the light yield from water would be higher than that of air and thus result in the higher counting efficiency you observed. Either way you may find this article of interest: cerncourier.com/cws/article/cern/50222
Reid Byron Hi Lord Byron ;-)If you take a look at the Frank-Tamm-formular it seems that the number of emitted photons d²N/dxdw just depends on the velocity v and the charge Z of the fast particle and the refractive index n of the medium. I can't see any remaining dependence... But the greater n (water 1.33, air nearly 1), the greater the angular phi and therefore the greater the term sin²(phi) in the Frank-Tamm-formular.So in water the energy-loss per meter should be greater than in air ;-)And to emit cherenkov-radiation in air the muons have to be faster than c / 1.000292 = c / n_air. Another reason for less radiation, because not every muon is as fast as this. In water they just have to be faster than c / 1.33 ...
stopperl16 Great explanation! The governing equations answer that question in its entirety. I know this is commonly done with plastic scintillators, but it would be interesting to run two of your water Cerenkov detectors in coincidence to add another layer of discrimination and certainty
Hi! The scintillator in this experiment is simple water. If a charged particle is faster than light in the medium (f.e. for water c = 225 000 km/s), then it emits cherenkov-light. The can is filled with water...
The results would be more meaningful if you had two identical tubes in separate cans, stacked on top of each other. Then you take the outputs and run them in to "Schmidt triggers" (for precise edge triggering on the event) and in to a logical AND gate (two integrated circuits would do it). If a muon event passes through both detectors from the same direction there will be a coincidence in each detector can and an indication that the event is coming from above. You could separate the two detectors to make the muon path much narrower but you might end up needing to create a coaxial cable delay line to offset the speed of light in the two detectors. Otherwise you would see two separate pulses that are only a few nSec apart. But the PMT's and scintillators should have enough persistence (afterglow) to overcome that effect.
You would use integrated circuits like the 74HC series devices that are very fast. If you wrapped the two detectors in lead and put lead beneath the array you could further reduce the impact of gamma rays.
Hi!Thank's for your hints. I've done that coincidence measurements with 3 geiger tubes to detect cosmic muons. Take a look at it. Greetings from Austria, stopperl th-cam.com/video/fF170T0rB1U/w-d-xo.html
Like a photomultiplier hodoscope, instead of a GM tube one.
Or you could gate the detector with GM tube pulses.
@@analogplanet9675 That will reduce the rate a lot. The cross sectional area of a typical GM tube is so small that the probability that a muon passes through the water tank also striking the GM tube is pretty low. Two PMTs in coincidence is the standard way to go.
Outstanding work.
Hello, is there any way to contact you? I am planning on doing a similar project for a college course but the technicians at my Uni have limited knowledge on PMT's. I'd like to know if it's possible to connect the raw output of the signal generated by a PMT to an oscilloscope (no pulse processing) and what equipment or circuits are needed to do it. For example, is there a simple adapter that exists for the PMT with BNC connectors that I can connect to a HV power supply and the output I can just connect to an oscilloscope? I saw a post where someone uses a T-splitter I think to acquire the signal but is that necessary?
Can we rule out some radioactive traces in the water?
by using distilled water you minimize interference to a respectable degree by having purer water. I'm not sure about ruling out radioactive traces in the water though, not entirely sure what you mean by radioactive traces. Do you mean radioactive decay of constituent water particles releasing photons and interfering?
Can you show me a video with you makeing the divice
Is the hertz rate of the electricity too slow to catch strikes? Or is it DC? How can you rule out background radiation? or is THIS background radiation? I'm a novice at this...
Muons represent a significant amount of ionizing background radiation, as I understand it something like 50%. In terms of hertz rate and stuff like that, I believe you can minimize it by sending the data to a computer and analyzing with computer software to, for example. minimize the x axis around the spike in order to make it easier to analyze. Generally speaking tho, any spike with the suddenness and amplitude of the one shown in the video on the screen will be associated with an actual detected photon (released as Cherenkov radiation from the muon interacting with water particles) which almost certainly comes from a muon.
Good work :) Is the number of muons varying somehow, depending on, for example, solar activity?
+Mieszko Guliński BTW: you could need to shield the detector against, for example, radioactivity. At first try using distilled water.
Love the music! What is the name of it and who is the composer?
Johann Sebastian Bach- Orchestersuite Nr. 3 D-Dur,Satz 2 - Air - BWV 1068
Beautiful!
What are you using for discrimination though?
a comparator...
Hi ! its a GD-24 lamp detector ??
Hi! It's an EMI 9785B photomultiplier ;-)
supply voltage 1.5 kV. Open contacts. Why do not you have a short circuit?
I use a negative voltage (-1.0 kV) for the photomultiplier, isolated by the BNC-connector. Therefore the Output-signals are measured against ground...
Thank you . this is a good idea! can you give a connection diagram?
Here's my thread concerning experiments with photomultiplier: forum.mosfetkiller.de/download/file.php?id=13960&mode=viewforum.mosfetkiller.de/viewtopic.php?f=6&t=61526&start=60
Fantastic! I hope to perform a similar experiment as well. Cerenkov light can be produced in air as well as in water. I do not know if the light yield from water would be higher than that of air and thus result in the higher counting efficiency you observed. Either way you may find this article of interest:
cerncourier.com/cws/article/cern/50222
Reid Byron Hi Lord Byron ;-)If you take a look at the Frank-Tamm-formular it seems that the number of emitted photons d²N/dxdw just depends on the velocity v and the charge Z of the fast particle and the refractive index n of the medium. I can't see any remaining dependence... But the greater n (water 1.33, air nearly 1), the greater the angular phi and therefore the greater the term sin²(phi) in the Frank-Tamm-formular.So in water the energy-loss per meter should be greater than in air ;-)And to emit cherenkov-radiation in air the muons have to be faster than c / 1.000292 = c / n_air. Another reason for less radiation, because not every muon is as fast as this. In water they just have to be faster than c / 1.33 ...
stopperl16 Great explanation! The governing equations answer that question in its entirety. I know this is commonly done with plastic scintillators, but it would be interesting to run two of your water Cerenkov detectors in coincidence to add another layer of discrimination and certainty
You forgot to show us you scintillator.
Hi! The scintillator in this experiment is simple water. If a charged particle is faster than light in the medium (f.e. for water c = 225 000 km/s), then it emits cherenkov-light. The can is filled with water...