Device and method for measuring an energy particle beam

A dosimetry device for an energy particle beam coming from a source and comprising at least first and second ionization chambers each comprising a collector electrode and a polarization electrode, said electrodes of each ionization chamber being separated by a gap or space comprising a fluid, said ionization chambers being configured to be passed through by an energy particle beam coming from a same source, wherein the ionization chambers have different charge collection efficiency factors, and the device comprises an acquisition device connected to a computer configured to perform an algorithm for calculating the dose rate deposited by said particle beam based on:

• measuring an output signal in each considered ionization chamber;
• and
• a gain factor relative to a first ionization chamber, given by the equation
• G
• =
• 1
• -
• (
• i
• ⁢
• ⁢
• 1
• i
• ⁢
• ⁢
• 2
• )
• norm
• 1
• -
• f
• 1
• where
• G is the gain factor relative to the first ionization chamber,
• (
• i
• ⁢
• ⁢
• 1
• i
• ⁢
• ⁢
• 2
• )
• norm
• is the ratio of theoretical values of output signals (i1 and i2) in the two considered ionization chambers normalized by the ratio of their respective amplification factors (R1/R2), each amplification factor depending on said fluid, the width of the gap and the penetration power of the particle beam in said fluid for a considered ionization chamber,
• f1 is the theoretical value of the charge collection efficiency factor in the first ionization chamber,
• said theoretical output signal values (i1, i2) and f1 being calculated as a function of intrinsic and/or extrinsic parameters of said considered chambers, and as a function of one or more pre-defined values of the current intensity of the particle beam, said gain factor G being independent of the value of said particle beam current intensity.