During ionization measurement processes, why is checking polarity important?

In ionization measurement processes, checking polarity is crucial because it significantly impacts the charge accumulation in the ionization chamber. When ionizing radiation interacts with the gas within the chamber, it creates ion pairs—positive ions and free electrons. The applied electric field in the ionization chamber facilitates the movement of these charged particles towards their respective electrodes.

If the polarity is not set correctly, the collection of these ions can be affected, which in turn alters the current measured and may lead to inaccurate readings. The correct polarity ensures that positive ions are collected at the anode and electrons at the cathode, thus maintaining an effective charge collection mechanism that accurately reflects the amount of radiation interacting with the gas in the chamber.

Correct polarity is essential to generate reliable and reproducible measurements of radiation dose, which is vital for proper dosimetry and treatment planning in medical applications.