| 摘要 |
<p>A mass spectrometer with phonon sensitive cryogenic particle detector (1) to determine the masses of macromolecules, including proteins, large peptides, long DNA-fragments and polymers. The kinetic energy of the electrostatically accelerated charged macromolecule (6) is absorbed in the cryogenic particle detector (1) thereby exciting phonons (7) which are detected by phonon sensors (2). The macromolecules are detected in the single particle counting mode with a sensitivity independent of their respective masses. In one embodiment, the mass spectrometer contains a single-channel cryogenic particle detector providing high sensitivity. In another embodiment, the mass spectrometer contains a spatially resolving multi-channel cryogenic detector array providing both high sensitivity and high throughput. In the latter embodiment, said mass spectrometer consists of a vacuum vessel in which is a magnet (48), a mass separator (50), a feed through (51) and a phonon sensitive cryogenic detector array (53). Said cryogenic detector array (53) consists of an absorber (42) and a specified number of phonon sensors (43). The mass separator (50) is placed in the magnetic field of the magnet (48) and is, together with the feed through (51), on electrical potential (U1), but electrically insulated from the magnet. The cryogenic detector array is on electrical ground potential (U2). The macromolecules are accelerated by the voltage difference U1-U2 and reach the cryogenic detector array (53) with a kinetic energy proportional to U1-U2. Said cryogenic detector array (53) is cooled to its operating temperature T2 by being thermally mounted to a cold finger (54) of the cryostat (58) with bath temperature T2. Said cryogenic detector array (53) is shielded from the magnetic field of the magnet (48) by a magnetic shield (52). The mass of the macromolecule is determined by the spatial and time information provided by said cryogenic detector array (53).</p> |
