Can high school students build their own cosmic ray detector?

[That one guy]

I'm new by the way, but I have just started reading "Physics of the Future" by Michio Kaku and found when he was in high school he built a cloud chamber (I assume a cosmic ray cloud chamber) and a betatron particle accelerator, I looked into it and found them both a bit simple, so i want to make something fun like that but somewhat of a challenge to complete.

P.S. I'm still a student in high school myself so please not too outrageous material wise

 

[xts]

You may build a do-it-yourself cloud chamber pretty easy. Just a bulb filled with vapour of e.g. alcohol, which turns to mist as decompressed using a quickly pulled syringe.

But cosmic rays are not that easy to detect: the flux at Earth level is about 1 per minute per cm^2, so you may spot one per hundred or so trials.

If you have something radioactive (e.g. old-fashioned watch with glowing arms) - it could help a lot...

 

[That one guy]

I meant I looked into it and I wanted to make something a bit more challenging, partially because i have friends who will help.

 

[xts]

Betatron is not that simple to build - it is possible to build it at home, but it require some experience with electronics, vacuum, etc.

If you have some basic experience in electronics and high voltage (don't kill yourself!) you may try to build gas chambers: either drift chamber (a bit more difficult) or spark chamber or (easiest) Geiger's counter.
You may want to build a pair of Geiger's counters first, and then use them as a trigger for spark chamber - and observe cosmic muons that way.

My son built a spark chamber when he was 17 - it took a month for him and his friend, but they did it finally, at expenses not much exceeding 100€ (well, they already had most of the electronic stuff needed).