# How Many Ion Pairs Will a Beta Particle Produce Inside a Helium-Filled Geiger Tube?

## Ionization Energy in Helium Gas

**The energy required to produce an ion pair (W) is typically around 33.97 electron volts (eV) in helium gas.** This means that for every ion pair produced, 33.97 eV of energy is needed. To convert this value to megaelectron volts (MeV), we divide by 1 million: W = 33.97 eV / 1,000,000 = 0.00003397 MeV.

## Calculating Number of Ion Pairs

Given that the kinetic energy of the beta particle is 0.159 MeV, we can calculate the number of ion pairs produced as follows: Number of ion pairs = (Kinetic energy of the beta particle) / (Ionization energy per ion pair). Therefore, Number of ion pairs = 0.159 MeV / 0.00003397 MeV/ion pair ≈ 4689 ion pairs.

Therefore, **the beta particle is estimated to produce approximately 4689 ion pairs inside the helium-filled Geiger tube.**