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STREAM335 |
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- Open-air ice-free cryogenic temperature control system
(Cryostreamer)
Application fields:
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√ Biological molecular crystallography
√ Material science
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The cryostreamer is designed for precise temperature control near the samples placed in open flow of cool cryogenic gas (nitrogen) without ice formation. Cryostreamer set consists of storage dewar with level gauge, liquid nigrogen/gas transfer line, gas generator, and nozzle. Cryogenic liquid is evaporated by a heater mounted at the end of the transfer line placed in the storage dewar. Then the mixture of the liquid and gas moves to the gas generator. The gas generator produces stable gas flow with a fixed temperature. In a case of the liquid nitrogen, the gas generator is placed within the dewar. In a case of the liquid helium, the gas generator is placed directly before the streamer nozzle. The nozzle forms two concentric streams, which differ in diameter about 1-2 mm. The hot outer gas beam with a circumference cross-section prevents the ice formation on the sample. The inner gas beam has a circular cross-section and containes cool gas flow directed to the sample. The temperature of the gas inside of the inner beam depends on the coordinate across the diameter. The temperature distribution has a minimum around the center of the beam within a spot with diameter 2-3 mm. Outside of this spot the temperature gradually increases up to room temperature. In the region of laminar gas flow, the inner and outer beams flow independently. The laminar flow diameter is of about the outer diameter of nozzle. The sample has to be placed within the laminar zone.
The temperature control system includes two heaters located at the nozzle and within the gas generator. A tSTAT335x temperature control unit that delivers an optimal consumption of cryogenic liquids and precise temperature regulation controls the heating power of heaters. The system can be equipped by a beam adjust set. The STREAM335x is good for the synchrotron radiation experiments, as well as for the X-ray measurements of small samples. It can be adapted also for AFM and STM microscopy. The applications of the cryostreamer relate to the temperature control in local regions on the open air without ice formation.
Technical parameters
Temperature range, K
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Liquid nitrogen
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90 – 400
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Liquid helium
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20 – 273
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Sample location within the laminar gas flow zone
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Present
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Laminar gas flow zone length, mm
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10
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Inner nozzle diameter, mm
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8
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Cold spot diameter at the centre of the laminar zone, mm
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2 – 3
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Temperature stability, K
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±0.4
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Heating/cooling time on 100 K, min
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<20
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Cryogenic liquids consumption, l/hour
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1.2
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Maximum heater power, W
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320
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Thermocouple (N2)
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NiCr/Ni
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Thermocouple (He)
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Cu/Cu:Fe
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Electronic reference point for the thermocouple
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Present
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PID temperature control system
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Present
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Liquid cryogen level indicator with alarm signal
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Present
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Flash memory
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Present
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RS-232 interface
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Present
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Power supply
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50 Hz, 220 V ±10 %
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Maximum power supply, W
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420
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Postal address: |
RTI Ltd., Institutskaya str. b.2, 142432 Chernogolovka, Moscow region, Russian Federation |
Phone: |
+7 800 100-29-70 |
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