not just described, Explained


Contact us

Misconceptions quiz

Subscriptions FAQ




Physics subscription prices

subscribe log in



Work and Money

PSHE subscription prices

subscribe log in

Beta particles, lead and X-rays

Lead isn't just toxic

Though lead would seem like a good way to shield yourself from beta particles this isn't always the case.

Try Why Do Astronauts Float by Julian Hamm

All beta sources, like strontium-90, emit betas with a range of energies but some sources have higher peak energies than others.

If a high energy beta interacts with an atom of a dense metal like lead then X-rays can be given off.  This is called Bremsstrahlung or ‘braking radiation’.  In fact X-ray machines work by accelerating electrons to high speeds before smashing them into a metal target.

X-rays are weakly ionizing but can pose a danger to you if you receive lots of doses.

So it’s better to shield high energy beta particles with a less dense material like Perspex to stop X-rays being produced.  Remember these X-rays are only given off while the beta radiation is striking the lead.  The lead does not become radioactive.

back to Lesson 2: Alpha, Beta and Gamma