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We present the first experimental results obtained using a cryogenically-cooled Nb-Al,O,-Nb superconductorinsulator-superconductor (SIS) tunnel junction detector operating at 1.3 K as an ion detector in a time-of-flight mass spectrometer. As opposed to microchannel-plate ion detectors (MCPs) commonly used in such systems, cryogenic detectors such as SIS detectors offer a near 100% detection efficiency for all ions including single, very massive, slow-moving macromolecules. We describe the operating principle of an SIS detector and its use as an ion detector in our matrix-assisted laser desorptionlionization (MALDI) time-of-flight mass spectrometer and compare its response to an MCP detector operated in the same system. To our knowledge, this is the first direct comparison of these detector types in this application. A comparison of count rates and time-of-flight spectra obtained with both detectors for human serum albumin (molecular weight 66 000 Da) indicates a two to three orders of magnitude higher detection efficiency per unit area for the SIS detector at this mass. For higher molecular masses we expect an even higher relative efficiency for cryogenic detectors since MCPs show a rapid decline in detection efficiency as ion mass increases, which is not expected to be the case for cryogenic detectors.Our results imply that time-of-flight techniques could be extended beyond the current upper mass limit if cryogenic detectors are used. Initially, cryogenic detectors will be used for the analysis of large protein molecules. If non-fragmenting ionization techniques can be perfected, cryogenic detectors will also open the possibility of the rapid analysis of large DNA molecules and perhaps intact microorganisms.Cryogenic detectors' are a new class of very sensitive, energy-resolving, low-threshold particle detectors which are currently being developed for a variety of applications such as X-ray spectroscopy,2 optical ~pectroscopy,~ and searches for dark matter in the form of weakly interacting massive particles (WIMPS).~ Cryogenic detectors rely on measuring low-energy solid-state excitations as part of their detection mechanism, and therefore must be operated at temperatures typically below 2 K to avoid excess thermal excitations. The energy of these excitations, typically S 5 meV, is much less than the -eV energies needed to produce secondary electrons or electronic excitations in conventional ionization detectors. Thus a relatively large number of excitations is created for given energy deposition which allows the energy to be measured with smaller statistical error and thus much greater precision. The low excitation energy also makes cryogenic detectors more sensitive to weakly ionizing, slow moving particles than ionization detectors. Therefore, cryogenic detectors are ideal for application in time-offlight mass spectrometers used to measure the masses of large species, such as massive biomole~ules.~~~ In a typical mass spectrometer, large ions move too slowly to be efficiently detected by an ionization detecto...

Studies validating rational variants of the development of energy supplies for distributed consumers in the eastern regions of Russia on the basis of the availability of energy resources, transport access, and economic efficiency are indicated in this article. The efficiency and site conditions for the best expansion of a centralized electricity supply, siting of mini thermal and power plants using local fuel, renewable energy sources, low-capacity nuclear power plants, and gas in gas-diesel electricity plants are presented. Proposals are made for developing rational schemes for supplying energy to consumers supplied from the Chaun-Bilibino power system in the Chukotka Autonomous District.More than 60% of the territory of the eastern regions of Russia is not covered by centralized power delivery. The boundary of the delivery zone of energy systems in the eastern part of the country passes almost along the boundary of the Extreme North and the regions equated to it. In the northern regions, only a negligible part of the territory lies within the zone of local operating power systems. Here, the energy for a large part of the populated points is supplied by 5000 autonomous low-capacity power plants (to 30 MW), whose fraction in the total power-plant capacity in the northern regions is >27% (Table 1) [1]. The autonomous energy sources are primarily diesel electricity plants and gas-turbine facilities. Very few renewable energy sources are used in the eastern regions: only five geothermal electricity plants with total capacity 84 MW, five small hydroelectric plants with capacity 29 MW, and three wind power plants with total capacity 3.25 MW [1].The dispersal of the energy sources over the territory, a weak transportation infrastructure, and the multiunit nature and seasonality of fuel delivery increase the cost of energy considerably (diesel fuel to 36000 rubles/ton, boiler-furnace fuel to 6000-8000 rubles/TEF). In the most remote populated points, the transport component of the fuel costs reaches 70-80%. All this makes for high cost of production of energy -5-10 times higher than that of energy produced by power plants in local power systems (to 15-18 rubles/(kW·h) and 4000-5000 rubles/Gcal). The yearly subsidy for equalizing prices from the budget of different levels are estimated to be 50·10 9 rubles, which in some regions amounts of 20-30% of the budgeted outlay.Research on validating the strategic directions of development of fuel-energy complexes in the eastern regions of the country has been on-going at the Melentiev Institute of Energy Systems of the Siberian Branch of the Russian Academy of Sciences since the 1980s. The main directions of development of electricity and heat production for regions in the Extreme North and the territories equated to them up to 1990 and in the future to 2000 were developed over this period of time [2,3]. The Institute took an active part in many works on formulating the eastern energy policy of the country. Regional govern-