Fast-cool-down mixed-refrigerant Joule-Thomson cryocoolers used for cooling infrared devices

Due to its high efficiency, fast cool-down, small size, light weight, low power consumption, high reliability, Stirling cycle machine has many successful commercial applications such as heating and cooling. In the present paper, performances of a Beta type Stirling machine having a regenerative displacer were investigated. Energy analysis is reproduced taking into account complex phenomena related to compressible fluid mechanics, thermodynamics and heat transfer. A special attention is paid to the effect of such operating parameters as pressure, temperature, frequency and cooling water flow rate on Beta type regenerative Stirling machine performances. A MATLAB program was developed. Net cooling capacity, imputed work and COP inside the machine were assumed and compared to the experimental values. Comparing the results obtained by this code with experimental data, an acceptable agreement can be deduced for the predicted performance of the Stirling machine. The optimum speed is investigated.

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Effects of Deliberate Metal Contamination on CCD Imagers

MRS Proceedings ◽

10.1557/proc-262-769 ◽

1992 ◽

Vol 262 ◽

Cited By ~ 4

Author(s):

William C. McColgin ◽

J. P. Lavine ◽

J. Kyan ◽

D. N. Nichols ◽

J. B. Russell ◽

...

Keyword(s):

High Temperature ◽

Metal Contamination ◽

Temperature Step ◽

Fast Cool ◽

Charge Coupled Device ◽

Iron Cobalt ◽

Cobalt Nickel ◽

Nickel Copper ◽

Purity Iron ◽

High Purity Iron

ABSTRACTThe effects of intentional metal contamination on silicon charge-coupled device imagers are reported. Such imagers are both sensitive to and provide sensitive measures of the presence of metals in the fabrication process. High-purity iron, cobalt, nickel, copper, palladium, and gold were deliberately introduced into the device wafers just before the last high temperature step. Metals were found to cause both electrical defects and distinctive imaging defects.We find that transition metals can be effectively removed from device regions by internal gettering, but that this gettering can be defeated by a fast cool-down. Gold, however, is poorly gettered.

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Fast cool-down coaxial pulse tube microcooler

10.1117/12.2238285 ◽

2016 ◽

Author(s):

T. Nast ◽

J. R. Olson ◽

P. Champagne ◽

E. Roth ◽

G. Kaldas ◽

...

Keyword(s):

Pulse Tube ◽

Fast Cool

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Performance of A Laser-Pulsed Thermal Electron Gun

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100179373 ◽

1990 ◽

Vol 48 (1) ◽

pp. 124-125

Author(s):

O. Bostanjoglo ◽

F. Heinricht ◽

F. Wünsch

Keyword(s):

High Speed ◽

Operation Mode ◽

Electron Gun ◽

Fast Cool ◽

Thermal Electron ◽

High Brightness ◽

Tungsten Surface ◽

Set Up ◽

Electron Pulses ◽

532 Nm

High-speed electron microscopy strongly demands a high-brightness electron gun in order to increase the number of image forming electrons. A few years ago, a laser-pulsed high-brightness electron gun was introduced. Fig.1 shows the experimental set-up, A standard triode system was supplemented with a Nd:YAG laser, focussing optics and a modified anode, which incorporates the laser deflection mirror. The frequency doubled laser pulse (τ =5 ns, λ = 532 nm) is focused through a window onto the tip of the tungsten hairpin emitter. The laser treated area (≈ 100 μm diameter) is heated well above the melting point, which results in a strong thermal electron emission. Due to rapid heat-up and fast cool-down of the tungsten surface short electron pulses with a duration of 20 ns and a maximum current of 20 mA at 80 kV are emitted. A destruction of the tungsten wire is avoided, too. Laser energies used for the generation of electron pulses are in the range of 100 μJ. Due to these minor modification, the DC operation of the electron gun is not disabled, which allows a convenient adjustment in the DC mode and then switching into the pulsed operation mode. Fig.2 shows a typical electron pulse emitted by the gun. Shorter electron pulses up to 5 ns can be generated by a beam blanking unit.

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A helium mini-cryostat for the nanoprobe beamline ID16B at ESRF: characteristics and performance

Journal of Synchrotron Radiation ◽

10.1107/s1600577520007110 ◽

2020 ◽

Vol 27 (4) ◽

pp. 1074-1079

Author(s):

Ricardo G. Steinmann ◽

Gema Martinez-Criado ◽

Damien Salomon ◽

Hugo Vitoux ◽

Remi Tucoulou ◽

...

Keyword(s):

Thermal Stability ◽

Quantum Wells ◽

Excellent Performance ◽

Fast Cool ◽

X Ray ◽

Mechanical Constraints ◽

Technical Requirements ◽

Optical Luminescence ◽

Bulk Gan ◽

And Performance

A helium mini-cryostat has been developed for the hard X-ray nanoprobe ID16B of the European Synchrotron to collect X-ray excited optical luminescence and X-ray fluorescence at low temperature (<10 K). The mini-cryostat has been specifically designed to fit within the strong space restrictions and high-demanding mechanical constraints imposed by the beamline to provide vibration-free operation and maximal thermal stability. This paper reports the detailed design, architecture and technical requirements of the mini-cryostat, and presents the first experimental data measured using the cryogenic equipment. The resulting cryo-system features ultimate thermal stability, fast cool-down and ultra-low vibrations. The simultaneous X-ray fluorescence and X-ray excited optical luminescence data acquired from bulk GaN and core/shell InGaN/GaN multi-quantum wells validated the excellent performance of the cryostat with ultimate resolution, stability and sensitivity.

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