Patent ID: 6476397
Filing Date: 2002-11-05
Classification: G01T,H01J

Abstract:
A detector for detection of ionizing radiation, comprising:a chamber filed with an ionizable gas, and including a first and a second electrode arrangement, substantially in parallel with each other, between which a first voltage is applicable; a radiation entrance arranged such that radiation can enter the chamber between and substantially in parallel with the first and second electrode arrangements, for ionization of the ionizable gas; an electron avalanche amplification arrangement including an avalanche cathode arrangement and an avalanche anode arrangement, between which a second voltage is applicable; and a read-out arrangement; wherein the first voltage is applicable for drifting electrons created during ionization towards the electron avalanche amplification arrangement, the second voltage is applicable for avalanche amplification of said electrons, and the read-out arrangement is arranged for detection of electron avalanches and/or correspondingly produced ions; the chamber is arranged such that radiation entering through the radiation entrance enters a first chamber section having a first distance between the first and second electrode arrangements and then enters a second chamber section having a second distance between the first and second electrode arrangements, the first and second distances being different; and the read-out arrangement is arranged such that electron avalanches, and/or correspondingly produced ions, derivable mainly from ionization in the respective chamber section are separately detectable.