scholarly journals Modernization of NASA Johnson Space Center’s Chamber A to support Cryogenic Vacuum Optical Testing of the James Webb Space Telescope (JWST)

2021 ◽  
Vol 64 (1) ◽  
pp. 30-41
Author(s):  
Mary Cerimele ◽  
Jonathan Homan ◽  
Sam Garcia ◽  
Jaime Garza ◽  
Gabriel Hirsch ◽  
...  
Keyword(s):  
Vacuum Chamber ◽  
High Vacuum ◽  
Vacuum System ◽  
Thermal Vacuum ◽  
Space Telescope ◽  
James Webb Space Telescope ◽  
Cryogenic Vacuum ◽  
Optical Test ◽  
The World ◽  
Helium Refrigeration

Abstract NASA is the mission lead for the James Webb Space Telescope (JWST), the next of the “Great Observatories,” scheduled for launch in 2021. NASA is directly responsible for the integration and test (I&T) program that culminated in an end-to-end cryo vacuum optical test of the flight telescope and instrument module in Chamber A at NASA Johnson Space Center. Historic Chamber A is the largest thermal vacuum chamber at Johnson Space Center and one of the largest space simulation chambers in the world. Chamber A has undergone a major modernization effort to support the deep cryogenic, vacuum and cleanliness requirements for testing the JWST. This paper describes the upgrades to the Chamber A facility: Thermal Shrouds, Helium Refrigeration, Liquid Nitrogen System, High Vacuum System, Clean Airflow System, and Utilities.

Design on High Vacuum System with Molecular Pump

2012 ◽  
Vol 220-223 ◽  
pp. 459-462 ◽  
Author(s):  
Chong Zhang ◽  
Jin Hua Zheng ◽  
Cong Hui Li ◽  
Yun Feng Chao ◽  
Long Jun Li ◽  
...  
Keyword(s):  
Molecular Sieve ◽  
Vacuum Chamber ◽  
High Vacuum ◽  
Vacuum System ◽  
Measuring Instruments ◽  
Vane Pump ◽  
Two Stage ◽  
Rotary Vane Pump

This paper aimed at finishing a two-stage oil-free high-vacuum system using a molecular pump as the main pump and a rotary vane pump as the backing pump. Before the pump’s inlet, there is a molecular sieve. With the assistance of the high and low vacuum measuring instruments and other accessories, the system can achieve limiting vacuum of 5×10-5Pa in the vacuum chamber whose volume is 0.085m3 and provide the high vacuum needed for vacuum coating equipments whose magnitude is 100mm.

Testing the equipment for the cryogenic optical test of the James Webb Space Telescope

2014 ◽  
Author(s):  
Tony L. Whitman ◽  
K. J. Dziak ◽  
Jesse Huguet ◽  
J. Scott Knight ◽  
Carl Reis ◽  
...  
Keyword(s):  
Space Telescope ◽  
James Webb Space Telescope ◽  
Optical Test

Design on UHV System with TSP

2013 ◽  
Vol 310 ◽  
pp. 319-322
Author(s):  
Jin Hua Zheng ◽  
Cong Hui Li ◽  
Chong Zhang ◽  
Yun Feng Chao
Keyword(s):  
Vacuum Chamber ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Normal Operation ◽  
Vacuum System ◽  
Measuring Instruments ◽  
Total Flow ◽  
Vane Pump ◽  
Rotary Vane Pump ◽  
The One

A UHV(ultra-high vacuum) system, which used as deposition equipment with the assistance of high and low vacuum measuring instruments and other accessories, was designed in this paper. A CMP (composite molecular pump) in parallel with TSP (titanium sublimation pump) as the main pump and a rotary-vane pump as the backing pump were designed in this system. After a CMP with displacement 2300l/s was chosen as the one of the main pumps, the total flow conductance between the outlet of vacuum chamber and the CMP was 1344l/s. The rough pump-down time was approximate 5 min by using a rotary-vane pump with pumping speeds 15l/s. In order to ensure the normal operation of the main pumps, a water chilling unit was designed in the system, which can achieve limiting vacuum of 5×10-6Pa in the vacuum chamber of 0.2 m3.

Design, Manufacturing and Pump-down Curve Simulation of High Vacuum Systems

2012 ◽  
Vol 220-223 ◽  
pp. 575-579
Author(s):  
Tien Tung Chung ◽  
Chih Kang Lu ◽  
Yi Ting Tu
Keyword(s):  
Vacuum Chamber ◽  
Extreme Ultraviolet ◽  
High Vacuum ◽  
Vacuum Pressure ◽  
Vacuum System ◽  
Extreme Ultraviolet Lithography ◽  
Ultraviolet Lithography ◽  
Vacuum Chambers ◽  
Equivalent Length ◽  
Vacuum Systems

This paper presents a vacuum system design for extreme ultraviolet lithography (EUV) and studies the prediction of pump-down curves for vacuum chambers. Related basic theories include gas laws, conductance for several kinds of flow regimes, equivalent length for pipes, outgassing, diffusion, and permeation etc. The simulation program consists of a MFC module and a MATLAB module. The MFC module is used to input necessary parameters, including start and target pressure for pumping, volume and inner surface area of vacuum chambers, configuration of pumping lines, performance of vacuum pumps, and gas loads. The MATLAB module deals with the pump-down curve calculation based on related theories. The governing equation of the conservation of mass in a pumped vacuum chamber is derived from extended Temkin isotherm. The pump-down curve of vacuum chamber is predicted by four steps, including calculation of equivalent length for pipes, conductance of pipes, and effective pumping speed of pumps, and pump-down time. An empty vacuum chamber is used to test the developed program. The pump-down curve reaches 6.5E-8 torr with 42 hours pump-down time in experiment measurement, and the simulated curve reaches 5.79E-8 torr at the same time point. The developed program can predict pump-down curve with a good accuracy in the range from low vacuum pressure to high vacuum pressure.

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