| 摘要 |
A detector for detection of ionizing radiation comprises a chamber (13) filled with an ionizable gas, and including a first (17, 19) and a second (21) electrode arrangement between which a first voltage (U1, U2) is applicable, a radiation entrance (33) arranged such that radiation (1) 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 (15) including an avalanche cathode arrangement (25) and an avalanche anode arrangement (27), between which a second voltage (Ua) is applicable, and a read-out arrangement (29), 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 the electron avalanches and/or correspondingly produced ions. The invention comprises that the chamber is arranged such that radiation entering through the radiation entrance will firstly enter a first chamber section having a first distance (d1) between the first and second electrode arrangements and then enter a second chamber section having a second distance (d2) between the first and second electrode arrangements, the first (d1) and second (d2) distances being substantially different, and that 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. |
