scholarly journals STG-CT: High-vacuum plume test facility for chemical thrusters

2016 ◽  
Vol 2 ◽  
Author(s):  
Martin Grabe
Keyword(s):  
Liquid Helium ◽  
Molecular Hydrogen ◽  
High Vacuum ◽  
Test Facility ◽  
Plume Flow

The STG-CT, operated by the DLR Institute for Aerodynamics and Flow Technology in Göttingen, is a vacuum facility specically designed to provide and maintain a space-like vacuum environment for researching plume flow and plume impingement from satellite reaction control thrusters. Its unique liquid-helium driven cryopump of 30m2 allows maintaining a background pressure <10^-5 mbar even when molecular hydrogen is a plume constituent.

scholarly journals STG-ET: DLR electric propulsion test facility

2017 ◽  
Vol 3 ◽  
Author(s):  
Andreas Neumann
Keyword(s):  
Electric Propulsion ◽  
Vacuum Chamber ◽  
High Vacuum ◽  
Test Facility ◽  
Space Propulsion ◽  
Beam Dump ◽  
Pumping System ◽  
Thrust Measurement ◽  
Electric Space

DLR operates the High Vacuum Plume Test Facility Göttingen – Electric Thrusters (STG-ET). This electric propulsion test facility has now accumulated several years of EP-thruster testing experience. Special features tailored to electric space propulsion testing like a large vacuum chamber mounted on a low vibration foundation, a beam dump target with low sputtering, and a performant pumping system characterize this facility. The vacuum chamber is 12.2m long and has a diameter of 5m. With respect to accurate thruster testing, the design focus is on accurate thrust measurement, plume diagnostics, and plume interaction with spacecraft components. Electric propulsion thrusters have to run for thousands of hours, and with this the facility is prepared for long-term experiments. This paper gives an overview of the facility, and shows some details of the vacuum chamber, pumping system, diagnostics, and experiences with these components.

Environmental Testing of High Tc Superconductive Thermal Isolators for Space-Borne Cryogenic Detector Systems

1992 ◽  
Vol 275 ◽  
Author(s):  
Stephanie A. Wise ◽  
John D. Buckley ◽  
Henry W. Randolf ◽  
Darren Verbelyi ◽  
Gene H. Haertling ◽  
...  
Keyword(s):  
Liquid Helium ◽  
High Vacuum ◽  
Far Infrared ◽  
Fused Silica ◽  
Ir Detectors ◽  
Cryogenic Detector ◽  
Environmental Testing ◽  
Long Term Storage ◽  
Electrical Connections

ABSTRACTNASA's requirements for space-based cryogenic detector systems include the long-term storage of the liquid helium cryogen necessary for the optimized performance of far-infrared (IR) detectors. Significant heat loads on the liquid helium dewars exist due to the numerous electrical connections to the detectors, accounting for approximately 20 percent of the total heat load for some systems. High temperature superconductor lead assemblies are under development to replace the existing manganin wires connecting instruments at 80 K to the detector array at 4.2 K. These superconductive elements provide adequate current transport properties, while decreasing the thermal load on the liquid helium dewar. As a result, mission lifetimes can be extended by 10 percent or more.Thick films of the superconductive material on low thermal conductivity substrates (e.g. yttria stabilized zirconia and fused silica) have been proposed to replace the existing lead assemblies. This work describes some of the design constraints on such a device as well as preliminary analyses of the effects of vibration, gamma irradiation, and long term exposure to high vacuum and liquid nitrogen encountered in operating such a device in space.

A Liquid Helium Cryostat for a Superconducting Objective and Cold Stage

1976 ◽  
Vol 34 ◽  
pp. 532-533
Author(s):  
R. E. Worsham ◽  
J. E. Mann
Keyword(s):  
Liquid Helium ◽  
High Vacuum ◽  
Strong Support ◽  
Liquid Helium Temperature ◽  
Ultra High Vacuum ◽  
Objective Lens ◽  
Helium Temperature ◽  
Different Temperatures ◽  
Radiation Shields ◽  
High Coherence

In the design of the 150 kV High-Coherence Column, it was considered essential that the specimen be in ultra-high vacuum at liquid helium temperature for minimum radiation damage. It followed that the simplest solution was to make the entire region about the specimen at liquid helium temperature and to make the objective lens with a superconducting winding.For mechanical rigidity, two things were considered essential. First, a strong support structure for the liquid helium vessel and the objective lens. Second, the use of no liquid nitrogen but rather the use of helium vapor cooling for the radiation shields, leads and supports. The drawing, fig. 1, shows the helium vessel, 9-1/2-inches diameter by 5-inches tall, surrounded by two concentric radiation shields. The entire assembly is rigidly supported on four posts one of which is shown. These posts consist of cylinders of epoxyglass (G-10) spacing the components between their different temperatures.

Liquid Helium Cryostat for the Imaging System of a High Resolution Electron Microscope

1975 ◽  
Vol 33 ◽  
pp. 154-155
Author(s):  
D. L. Musinski ◽  
S. T. Wang ◽  
B. M. Siegel
Keyword(s):  
High Resolution ◽  
Liquid Helium ◽  
Imaging System ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Basic Design ◽  
Optimum Conditions ◽  
Resolution Electron ◽  
High Resolution Electron Microscope ◽  
High Resolution Microscopy

The specimen environment for high resolution microscopy of biomolecular materials is critical. To obtain the optimum conditions we maintain the specimen in an ultra high vacuum (10-10 Torr) and at liquid helium temperatures to minimize contamination and hopefully radiation damage. To meet these specifications, the imaging system composed of the cryostat shown in the schematic drawing was developed and constructed. Besides assuring that the basic design does not limit the desired resolution, our cryostat offers the maximum in engineering flexibility so alternate lens configurations or even extensive design modifications are relatively easy to accomplish.

Atomic and molecular hydrogen isotopes in liquid helium

1985 ◽  
Vol 31 (3) ◽  
pp. 1346-1351 ◽  
Author(s):  
K. E. Kürten ◽  
M. L. Ristig
Keyword(s):  
Liquid Helium ◽  
Molecular Hydrogen ◽  
Hydrogen Isotopes

Initial experimental results from the new DLR-High Vacuum Plume Test Facility STG

1997 ◽  
Author(s):  
Georg Dettleff ◽  
Klaus Plaehn ◽  
Georg Dettleff ◽  
Klaus Plaehn
Keyword(s):  
High Vacuum ◽  
Experimental Results ◽  
Test Facility
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