CONTACTLESS METHOD FOR DETERMINING THE RAY OF A BEAM, CORRESPONDING SYSTEM

摘要

The invention relates to a method for measuring a ray r0 of a radiation beam (20), characterized in that it comprises the steps according to which a source (2) of a radiation beam (20) excites (S1) a standard member (1) via heat, in a periodic manner at a frequency (f), thereby obtaining a periodic thermal excitation of the standard member (1); a sensor (3) measures (S2) a periodic in thermal response on the part of the standard member, in response to the periodic thermal excitation; a processor (4) determines (S3) a phase shift (φ) between the periodic thermal excitation and the periodic thermal response; the source (2) exciting the standard member for a plurality of frequencies (f) and the processor (4) determining a phase shift for each frequency (f), and thereby determining a plurality of phase shifts (φ); the processor (4) determines (S4) a minimum φ min of the phase shift (φ) thanks to the plurality of phase shifts determined in this manner, and determines (S5) the ray r0 of the beam (20) via the following formula: r0=Δ/g(φmin) where Δ is the thickness of the standard member (1) and where g is a function dependent on the type of heat radiation beam (20).

主权项

1. A method for measuring a radius r0 of a radiation beam, comprising:
a source of a radiation beam excites (S1) via heating, a standard member, periodically at a frequency, in order to obtain a periodic thermal excitation of the standard member; a sensor measures a periodic thermal response of the standard member, in response to the periodic thermal excitation; a processor determines a phase shift between the periodic thermal excitation and the periodic thermal response; the source exciting the standard member for a plurality of frequencies and the processor determining a phase shift for each frequency, and thus determining a plurality of phase shifts; the processor
determines a minimum φmin of the phase shift by means of the thereby determined plurality of phase shifts, anddetermines the radius r0 of the beam with a formula of the type:
r0=Δ/g(φmin)wherein Δ is the thickness of the standard member, and
g is a function which depends on the type of heat radiation beam.