Muon Detector

[Antonio Zanardo]

I have built a muon detector with 20 GM tubes. They are arranged in two layers, each one connected to a coincidence circuit.

The instrument counts about 9000 muons an hour. My goal was to measure the variation of muon flux caused by magnetic solar events.

as  geomagnetic shield is affected by  solar activity.

The detector is workinng h24 from october 1st 2020, but so far I was unable to measure any count  differences.

Is the Sun too much quiet or is my detector dumb to solar effects?

Antonio Zanardo - Italy

[Vancanneyt Sander]

Muon flux at ground level should be around 1 per square centimeter per minute according to: http://www.cosmicwatch.lns.mit.edu/about

solar activity has been fairly low, we’re just climbing out of solar minimum but solar activity is still very low. De had one active periode in November with a few M-class flares but that was it. 

[Maxime Fiset]

So, a muon detector should be able to monitor solar activity?

Pray, tell me more

[Vancanneyt Sander]

There has been some studies about that and in one I read this:

Quote

The previous solar cycle can be split up into two different period: 1)2004-2008; and 2)2008-2010. During the first period, the solar activity was mild. In these 4 years, the number of muons increased from 400 to 9000. During the second period (when the solar activity was low), muon count decreased from 9000 to 60. The data is contradictory because it doesn't follow the same trend. One may assume that because muon count increased as solar activity decreased during the first period, the second period should show even more muons since the activity is at a minimum. Clearly, that doesn't happen. Muon count actually decreases as solar activity decreases in the second period. Because the solar cycle indirectly modulates the flux of high-energy galactic COSMIC RAYS entering the solar system, we thought that there would be some correlation between the solar cycle and muons. If we had more data, then we might've been able to come up with a more clear answer as to if there was a correlation.

 

[Antonio Zanardo]

So we actually don't know  if an increased magnetic solar activity casuses a decrease or an increase of muon counts.

As far as I know the Muon Flux  is  on average stable over a long period. Therefore, supposing  that my muon counter is not affected by any spurious noise, is it reasonable to say that a stepping up or down of counts relates to a change of solar magnetic activity, and just to it?

Antonio Zanardo

[Vancanneyt Sander]

In studies I keep seeing that muon detectors at ground leven suffer from a temperature and pressure effect on the readings. Please take a look at this research: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019JA026651

[Christopher S.]

If you want data comparable to MINOS, you'll want to dig, dig dig.... nearly a kilometer below ground. Otherwise, you're subject to an unacceptable amount of noise from the surroundings; in other words, a complete lack of control for the testing environment.