Physics Van 3-site Navigational Menu

Physics Van Navigational Menu

Q & A: Ion chambers

Learn more physics!

Most recent answer: 10/22/2007
Q:
what is a ion chamber ?
- Anonymous
A:
Hey there, great question! An ion chamber is a device that is typically used in radiation detectors. The ion chamber is filled with gas of some sort, and as radiation passes through the chamber, it ionizes some of the gas. This means that the radiation knocks some of the electrons off of the gas so that it forms a positively charged part (the gas ions) and a negatively charged part (the electrons). For example, an atom of argon gas could be ionized to form a positively charged argon ion (Ar+) and a free electron. There are two electrodes in the ion chamber; one at each end. The positively charged electrode is called the anode and the negatively charged electrode is called the cathode, and they become charged up when you apply a voltage to them. When the gas in the ion chamber is ionized by radiation, the positively charged gas ions are attracted to the cathode and the electrons are attracted to the anode. This flow of charges is an electric current that can be measured, and by analyzing this current you can figure out how much radiation is present! In other words, higher radiation means that more gas is ionized which means a higher electric current.

Thanks for your question!

(published on 10/22/2007)

Follow-up on this answer.