We photograph muons on the desktop. Instructions for use
Hi geektimes.
When thinking about space radiation detectors, the first thing that comes to mind is Geiger counters, scintillators, cooled detectors and other expensive and exotic equipment. However, as it turned out, it is possible to “catch” the particles much easier - with the help of a conventional digital camera.
')
How it works, details under the cut.
I found out about the possibility of such detection completely by chance from the article “ CAPTURING COSMIC RAYS WITH A DIGITAL CAMERA ”, published on www.cloudynights.com . I am completely far from nuclear physics, so the theoretical part is actually a free translation from that article.
Cosmic rays are high-energy particles flying in space at a speed almost reaching the speed of light. They were discovered back in the 1900s, when the presence of ionizing radiation, increasing at high altitudes, was discovered. The radiation energy was such that it penetrates even through the metal protection. It was discovered deep underground and under water.
As studies have shown, cosmic radiation is divided into primary and secondary. Primary - these are protons flying at high speed, nuclei of hydrogen, helium, and sometimes heavier elements. Some particles have an energy of 3 * 10 ^ 20 eV, which would be enough to light a 100-watt lamp for a second. Sources of such particles are supernova explosions, processes in neutron stars, galactic nuclei and black holes. Reaching the atmosphere of the Earth, the particles collide with the atoms and molecules of air, generating secondary radiation. At the surface of the Earth, it almost completely consists of muons , particles similar to electrons, but having a much larger mass. On the surface of the Earth, the muon energy is 4 GeV, which allows them to penetrate to a depth of 700m.
The muon flux on the surface is about 1 particle per square centimeter per minute (remember this number, it is useful to estimate how many particles will fly through the camera sensor). From primary radiation, only 3% of particles reach the surface of the Earth.
For us, the most interesting thing is that in addition to traditional methods such as Geiger counters, cosmic radiation is also detected by CMOS / CCD matrices. What we now begin.
In the process of detecting particles it is very convenient that for this you do not need to either fly into space, or even go to the mountains. It is quite enough to put the camera on the table, after closing the lens cover.
Task N1 - obtaining a sufficient number of shots. The camera is basically suitable for any, with the possibility of manual settings. Obviously, the larger the sensor area, the more collisions can be obtained. No extra light is needed, so the lens cap needs to be closed. The above article recommends excerpts of 1-3 minutes. In my case, there was a Basler ace camera, the maximum shutter speed of which is only 1s, this also works (particles still fly much faster), the only drawback of such a case is that you have to process more frames.
For the camera, a simple program was written using the Pylon SDK, which continuously takes photos, for other cameras you can certainly find something similar. ISO and shutter speed should be chosen so that, on the one hand, the frame was dark enough, on the other hand, that the sensitivity was the maximum possible.
In my case, the program worked for 4 hours, 7200 frames were recorded, each with an exposure of 1s. Obviously, the maximum particle flux comes from the sky above, so that the camera was put with the lens cover closed, the matrix facing up.
The next step is the task of automatically processing the results. A Python program was written that determines the maximum brightness for each frame. The results of the program are displayed in the form of a CSV file, for which it is easy to plot. Thus, if there is a bright spot on the frame, it will be highlighted among the rest.
(thanks for the tips in the comments on improving the quality of the code)
The result is a set of CSV lines, approximately of the following form:
index; MaxL; name;
0.80, capture-00000.tif;
1.81, capture-00001.tif;
2.80, capture-00002.tif;
3.81, capture-00003.tif;
The file can be saved and opened, for example, in Excel to build a graph.
The program does not work quickly. There was an attempt to parallelize processing into several streams, but for some reason this did not increase the speed. However, the speed here is not particularly critical - the processing time is insignificant compared with the time that the particle flew to Earth.
Honestly, I didn’t believe that something would work out. It was more interesting to open cvs as a graph and see the result. Horizontal frame number, vertical brightness in RGB. I remind you that the lens cap was closed.
Clearly visible peaks of brightness, which clearly stand out from the average noise level of the matrix. At the beginning, the increase in noise due to the heating of the chamber is also clearly visible.
It became interesting how particle registration looks “live”. The pictures are 100% cropped (fixed points are matrix noises):
As you can see, the method really works. Those interested are also invited to try and show results. It seems that under Android there are even ready-made programs for smartphones. Theoretically, a webcam can come up, the stream from which you can record as files using ffmpeg. If there are 2x identical cameras, it is also of interest to place the matrices parallel to each other, which will allow fixing the direction of flight of particles.
And finally, no less interesting is the fact that every minute dozens of charged particles fly through us, possessing energy sufficient to penetrate 700m of the earth's surface. How it affects the cells, it remains only to guess. However, there is a theory (and probably not unreasonable) that it is the cosmic radiation that is the very factor that caused the evolution. So if it were not for these particles, there would be no one to read this article.
When thinking about space radiation detectors, the first thing that comes to mind is Geiger counters, scintillators, cooled detectors and other expensive and exotic equipment. However, as it turned out, it is possible to “catch” the particles much easier - with the help of a conventional digital camera.
')
How it works, details under the cut.
Theory
I found out about the possibility of such detection completely by chance from the article “ CAPTURING COSMIC RAYS WITH A DIGITAL CAMERA ”, published on www.cloudynights.com . I am completely far from nuclear physics, so the theoretical part is actually a free translation from that article.
Cosmic rays are high-energy particles flying in space at a speed almost reaching the speed of light. They were discovered back in the 1900s, when the presence of ionizing radiation, increasing at high altitudes, was discovered. The radiation energy was such that it penetrates even through the metal protection. It was discovered deep underground and under water.
As studies have shown, cosmic radiation is divided into primary and secondary. Primary - these are protons flying at high speed, nuclei of hydrogen, helium, and sometimes heavier elements. Some particles have an energy of 3 * 10 ^ 20 eV, which would be enough to light a 100-watt lamp for a second. Sources of such particles are supernova explosions, processes in neutron stars, galactic nuclei and black holes. Reaching the atmosphere of the Earth, the particles collide with the atoms and molecules of air, generating secondary radiation. At the surface of the Earth, it almost completely consists of muons , particles similar to electrons, but having a much larger mass. On the surface of the Earth, the muon energy is 4 GeV, which allows them to penetrate to a depth of 700m.
The muon flux on the surface is about 1 particle per square centimeter per minute (remember this number, it is useful to estimate how many particles will fly through the camera sensor). From primary radiation, only 3% of particles reach the surface of the Earth.
For us, the most interesting thing is that in addition to traditional methods such as Geiger counters, cosmic radiation is also detected by CMOS / CCD matrices. What we now begin.
Practice
In the process of detecting particles it is very convenient that for this you do not need to either fly into space, or even go to the mountains. It is quite enough to put the camera on the table, after closing the lens cover.
Shooting
Task N1 - obtaining a sufficient number of shots. The camera is basically suitable for any, with the possibility of manual settings. Obviously, the larger the sensor area, the more collisions can be obtained. No extra light is needed, so the lens cap needs to be closed. The above article recommends excerpts of 1-3 minutes. In my case, there was a Basler ace camera, the maximum shutter speed of which is only 1s, this also works (particles still fly much faster), the only drawback of such a case is that you have to process more frames.
For the camera, a simple program was written using the Pylon SDK, which continuously takes photos, for other cameras you can certainly find something similar. ISO and shutter speed should be chosen so that, on the one hand, the frame was dark enough, on the other hand, that the sensitivity was the maximum possible.
In my case, the program worked for 4 hours, 7200 frames were recorded, each with an exposure of 1s. Obviously, the maximum particle flux comes from the sky above, so that the camera was put with the lens cover closed, the matrix facing up.
Treatment
The next step is the task of automatically processing the results. A Python program was written that determines the maximum brightness for each frame. The results of the program are displayed in the form of a CSV file, for which it is easy to plot. Thus, if there is a bright spot on the frame, it will be highlighted among the rest.
Python source code
import time, datetime import os, datetime from PIL import Image # Get all files in a folder and subfolders def getMediaFilesList(folder): file_paths = [] for root, directories, files in os.walk(folder): for filename in files: if ".jpg" in filename.lower() or ".png" in filename.lower() or ".tif" in filename.lower(): # Save full file path filepath = os.path.join(root, filename) file_paths.append(filepath) return file_paths # Analyze content of the image files def analyzeFiles(filesList, threshold): for index,path in enumerate(filesList): startTime = datetime.datetime.now() photo = Image.open(path) photo = photo.convert('L') b = max(set(photo.getdata())) dT = (datetime.datetime.now() - startTime).total_seconds() if b > threshold: print "{},{},{},{}; !!!".format(index, b, path, dT) else: print "{},{},{},{};".format(index, b, path, dT) folder = "/Users/XXX/BaslerCam2/" threshold = 130 filesList = getMediaFilesList(folder) print "Analyze {} files:".format(len(filesList)) analyzeFiles(filesList, threshold) print "Done" (thanks for the tips in the comments on improving the quality of the code)
The result is a set of CSV lines, approximately of the following form:
index; MaxL; name;
0.80, capture-00000.tif;
1.81, capture-00001.tif;
2.80, capture-00002.tif;
3.81, capture-00003.tif;
The file can be saved and opened, for example, in Excel to build a graph.
The program does not work quickly. There was an attempt to parallelize processing into several streams, but for some reason this did not increase the speed. However, the speed here is not particularly critical - the processing time is insignificant compared with the time that the particle flew to Earth.
results
Honestly, I didn’t believe that something would work out. It was more interesting to open cvs as a graph and see the result. Horizontal frame number, vertical brightness in RGB. I remind you that the lens cap was closed.
Clearly visible peaks of brightness, which clearly stand out from the average noise level of the matrix. At the beginning, the increase in noise due to the heating of the chamber is also clearly visible.
It became interesting how particle registration looks “live”. The pictures are 100% cropped (fixed points are matrix noises):
Conclusion
As you can see, the method really works. Those interested are also invited to try and show results. It seems that under Android there are even ready-made programs for smartphones. Theoretically, a webcam can come up, the stream from which you can record as files using ffmpeg. If there are 2x identical cameras, it is also of interest to place the matrices parallel to each other, which will allow fixing the direction of flight of particles.
And finally, no less interesting is the fact that every minute dozens of charged particles fly through us, possessing energy sufficient to penetrate 700m of the earth's surface. How it affects the cells, it remains only to guess. However, there is a theory (and probably not unreasonable) that it is the cosmic radiation that is the very factor that caused the evolution. So if it were not for these particles, there would be no one to read this article.
Source: https://habr.com/ru/post/369999/
All Articles