Using a Photomultiplier THERMATRON to Detect Single Photons

I've been a fan of Jeroen's YouTube channel for a while now.  He has a very nice approach, combining theoretical knowlege with practical experiments and equipment builds.  Here we see him using a photomultiplier tube and a board acquired in flea market to build his photon detector.  

This video has a lot to offer us.  First, there is a single thermatron.  There is a tube socket.  There is a (really small!) high-voltage power supply.  He uses an oscilloscope. There is a laser.  There are photons.  And at one point, a single photon.  

Having recently built a simple Wilson Cloud Chamber, my attraction to this device is easy to explain.  I suspect our friend Grayson will be interested in it for Thermatronic reasons.   There is a Part II.   Check out the YouTube channel: 

https://www.youtube.com/@HuygensOptics  

Here is more info on the channel and it's creator: 

Hi, my name is Jeroen and on the Huygens Optics channel I publish videos on personal projects. My main fields of interest are optics, mechanics and photolithography. The videos aren't targeted towards a general audience but for people with a passion for science and technology (e.g. my fellow nerds). The channel is named after the famous Dutch mathematician, astronomer and inventor Christiaan Huygens (1629-1695). He was the first to publish a mathematical description of the wave properties of light, and also discovered Saturn's rings.

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Thanks Jeroen

Cloud Chamber Finale

 

Today's aparatus (above).  Chamber is larger and I left the bottom sealed.  It sits directly atop a chunk of dry ice.  The spongeat the top is soaked in alcohol. 

This is a one minute clip.  It does seem a bit like watching paint dry, but you will see many atomic particles moving through the cloud. If you look to the right side of the screen you will see that the cloud has started to rain alcohol.  I will put additional clips on the Patreon site. 

Harry Cliff's wonderful book mentions the origins of the cloud chamber. 

Click for a better view. 

Click for a better view/

Here's an interesing site on cloud chambers: 

https://www.hep.phy.cam.ac.uk/scatter/cloud.html#:~:text=Operate%20the%20chamber%20in%20a,approximately%20parallel%20and%20horizontal%20beam.

And here's another one: 

https://scoollab.web.cern.ch/cloud-chamber#:~:text=The%20cloud%20chamber%20was%20one,dry%20ice%2C%20and%20Isopropyl%20alcohol.

I think that is all I will do on the cloud chambers.  This was a lot of fun, but I am running out of dry ice.  There is, however, a lot of room for improvement and experimentation here, and a project likes this puts you in touch with the earliest days of particle physics (as Harry Cliff explains above). Good luck on 1.22 nanometers! Please let us know how you do. 

Here is one more look at the "output" of my cloud chamber.  This is a ten minute video.   You can see many traces in this. Check it out: 

More Cloud Chamber traces. April 26, 2024 (youtube.com)

Thank you Charles Wilson.  And thank you C.L. Stong. 

Big Success with Cloud Chamber

 

My Cloud Chamber

It was time to take a break from building SSB transceivers.  I wanted to build something completely different.  I went with something that I've wanted to build since I was a kid. Sometime in the late 1960s, I read about a Wilson Cloud Chamber in the book "The Amateur Scientist" by C.L. Stong  (my mom got the book for me, at great sacrifice).  

You have to make a little cloud in a chamber.  When an atomic particle flies through (as they do!) it will leave a little trace in the cloud.  Cool.  Literally cool: This is a dry ice diffusion cloud chamber.  You make the cloud by putting isopropyl alcohol in blotter paper at the top of the chamber. You then cool the bottom part (a lot) using dry ice. The alcohol evaporates, then is cooled into a cloud by the low temperature of the dry ice. Fortunately, my local supermarket has started selling dry ice (it was harder to come by when I was a kid).  For the chamber, I used a plastic container from the same superpmarket. For the light source I used a little LED workshop flasllight.  

I saw traces immediately, while I was setting the thing up.   

Here are two videos of what I saw during that first hour:  

This one minute video shows the traces I saw.  Look for the little whisps of "smoke": 

(2125) Traces seen on day 1 - YouTube

This one shows a few more traces, but then BOOM at about 27 seconds.  Check it out.  What is that?  (Thinking about it some more, I think this may have just been some higher humidity air leaking into the chamber and condensing suddenly.) 

(2125) Day 1 with Cloud chamber - YouTube

Here's the C.L Stong book.  My project begins on page 307

http://www.ke5fx.com/stong.pdf

So what band would this be?  Something in the nanometer range, right? 

Here is a video showing what you see in a large cloud chamber: 

https://www.exploratorium.edu/video/cloud-chamber