Radioactivity is like the wild card of the universe, it’s totally unpredictable at the individual level, but fear not! We have some pretty cool tools to help us measure it.

• Geiger–Müller Tube (aka Geiger counter or GM tube)

• Purpose: To detect the cheeky beta-minus particles and the mysterious gamma photons.

• How it works

  • Think of it as a metal soda can filled with a cocktail of special gases. 🍹
  • One end is like a window made of mineral mica - this is the entrance for our beta-minus guests.
  • Inside, there's an electric party going on, with a voltage difference of a few hundred volts.
  • When beta particles or gamma photons gatecrash this party, they cause a tiny atom inside to split (ionize). And this creates a kind of electric dance. 🎉
  • More and more atoms get into this groove causing a current that our counter can detect.

• Special guest - Quenching Gas: One of the gases in the tube is the bouncer. It ensures the electric dance doesn’t go on for too long (otherwise, we wouldn't be ready for the next particle). This quick stopping is called quenching. The break time between detecting particles? That's the “dead time” of the tube.

• Spark Counter

  • Purpose: The alpha particle detector. Alpha particles are the big, burly cousins of beta particles.
• How it works
  • Imagine a tightrope (thin metal wire) under a large net (metal grid) - circus style! 🎪
  • There’s a super high voltage between the rope and the net.
  • When an alpha particle passes between them, it causes a bright spark. Kind of like a firework display. You can count these sparks with your eyes or electronically.

Hello young physicist! Ready to delve into the world of radioactivity? Hold on tight because this can get just a bit...radioactive.