Final answer:
Electrical current generated through ionization by x/gamma radiation in a Geiger counter is known as an ionization current. This principle allows the Geiger tube to detect radiation by measuring the current produced from ion pairs created when radiation deposits energy in the gas within the tube.
Step-by-step explanation:
Electrical current generated by a charge created in air through ionization by x/gamma radiation is referred to as an ionization current. This is a key principle in the operation of a Geiger counter, which uses this current to measure ionizing radiation levels. When a particle of ionizing radiation, such as gamma rays, deposits energy in a gas (like in a Geiger tube), it creates ion pairs. Assuming 1.0 MeV is deposited and each ion pair requires 30.0 eV to create, we first determine the number of ion pairs produced. This is calculated by dividing the total energy deposited by the energy required per ion pair (1.0 MeV / 30.0 eV = 33,333 ion pairs). When considering a time span for the applied voltage to sweep the ions out, measured in microseconds, it's possible to calculate the current using the formula I = Q/t.
For instance, in the given scenario (a), calculating the current involves finding the total charge (by multiplying the number of ion pairs by the charge of a single electron) and dividing it by the time (1.00 µs). In scenario (b), the current would be multiplied accordingly if the number of ion pairs is increased by a factor of 900 due to additional ionization from accelerated ions within the Geiger tube.