PARTICLE DETECTOR

PROBLEM TO BE SOLVED: To solve a problem in a detector for detecting a biological molecule with higher quantum efficiency without depending on the kind of the biological molecule and the mass of the same that it is difficult to realize a sensitive area of a cm size and a response rate comparable to or exceeding a microchannel plate (MCP). SOLUTION: A strip line is formed of a superconducting thin film and the strip line is maintained under the temperature equal to or lower than the superconducting transfer temperature and is driven with a DC constant current or an AC current which is lower than a superconducting critical current. The superconducting state is broken and permanent conducting state appears in the area (hot spot) where density is high in the state of excited phonon, locally excited electron by ion impact or electron generated via local temperature rise. Since energy of biological molecule ion is several tens of keV, only a part of the strip line transfers to the permanent conducting state and a voltage signal is generated due a change in resistance. COPYRIGHT: (C)2004,JPO&NCIPI