Measurement and Control of Leakage in High Vacuum Systems

1948 ◽  
Vol 40 (5) ◽  
pp. 791-794 ◽  
Author(s):  
Robert B. Jacobs
Keyword(s):  
High Vacuum ◽  
Vacuum Systems ◽  
And Control ◽  
Measurement And Control

scholarly journals Design and Simulation of a Wireless SAW–Pirani Sensor with Extended Range and Sensitivity

Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2421 ◽  
Author(s):  
Sofia Toto ◽  
Pascal Nicolay ◽  
Gian Luca Morini ◽  
Michael Rapp ◽  
Jan G. Korvink ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
High Vacuum ◽  
Industrial Processes ◽  
Extended Range ◽  
Vacuum Sensor ◽  
Gas Kinetic Theory ◽  
And Control ◽  
Measurement And Control

Pressure is a critical parameter for a large number of industrial processes. The vacuum industry relies on accurate pressure measurement and control. A new compact wireless vacuum sensor was designed and simulated and is presented in this publication. The sensor combines the Pirani principle and Surface Acoustic Waves, and it extends the vacuum sensed range to between 10−4 Pa and 105 Pa all along a complete wireless operation. A thermal analysis was performed based on gas kinetic theory, aiming to optimize the thermal conductivity and the Knudsen regime of the device. Theoretical analysis and simulation allowed designing the structure of the sensor and its dimensions to ensure the highest sensitivity through the whole sensing range and to build a model that simulates the behavior of the sensor under vacuum. A completely new design and a model simulating the behavior of the sensor from high vacuum to atmospheric pressure were established.

Rapid Thermal Annealing of As in Si

1985 ◽  
Vol 52 ◽  
Author(s):  
J. L. Hoyt ◽  
J. F. Gibbons
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
High Vacuum ◽  
Depth Profiling ◽  
Electrical Characterization ◽  
Wide Range ◽  
Time Cycle ◽  
Series Of Experiments ◽  
And Control ◽  
Measurement And Control

ABSTRACTThe results of a detailed investigation of the diffusion of ion implanted As in Si during Rapid Thermal Annealing (RTA) are reported. A series of experiments has been performed on samples implanted with As in a wide range of concentrations. The use of an improved thermocouple bonding technique enables precise measurement and control of the temperature versus time cycle for each individual sample. The RTA apparatus is designed to perform high vacuum annealing, eliminating the complications associated with point defect generating mechanisms at the surface, which are known to influence the diffusion of impurities in Si. Sample analysis includes depth profiling by SIMS and RBS, and electrical characterization employing VanderPauw and Spreading Resistance measurements.The resulting profiles have been analyzed via a numerical solution of the diffusion equation subject to the appropriate boundary conditions. With an effective As diffusivity of the form we find good simulation of all measured profiles with the standard values of D0 and D- from SUPREMIII and a one parameter fit to D= Recent results on the redistribution of low dose As implants in heavily phosphorus doped Si illustrate the strong Fermi level dependence. The model has also been successfully used to simulate RTA data in the literature where careful temperature measurements have been made.

A SYSTEM FOR PROTECTING AN OIL DIFFUSION PUMP AGAINST FAILURE OF THE MECHANICAL FORE PUMP, COOLING WATER, OR ELECTRICITY

1970 ◽  
Vol 28 ◽  
pp. 344-345
Author(s):  
W. C. Bigelow ◽  
F. B. Drogosz ◽  
S. Nitschke
Keyword(s):  
High Vacuum ◽  
Cooling Water ◽  
Effective Protection ◽  
Pump Line ◽  
Diffusion Pump ◽  
System Pressure ◽  
Control Relay ◽  
Vacuum Systems ◽  
Vacuum Gage ◽  
Pressure Switch

High vacuum systems with oil diffusion pumps usually have a pressure switch to protect against Insufficient cooling water; however, If left unattended for long periods of time, failure of the mechanical fore pump can occur with equally serious results. The device shown schematically in Fig. 1 has been found to give effective protection against both these failures, yet it is inexpensive and relatively simple to build and operate.With this system, pressure in the fore pump line is measured by thermocouple vacuum gage TVG (CVC G.TC-004) whose output is monitored by meter relay MRy (Weston 1092 Sensitrol) which is set to close if the pressure rises above about 0.2 torr. This energizes control relay CRy (Potter & Brumfield KA5Y 120VAC SPDT) cutting off power to solenoid-operated fore line valve Vf (Cenco 94280-4 Norm. Closed) which closes to prevent further leakage of air into the diffusion pump

2. Measurement and Control of Airborne Microorganisms Using Electrostatic Methods

2001 ◽  
Author(s):  
G. Mainelis ◽  
R. Gorny ◽  
K. Willeke ◽  
S. Grinshpun ◽  
T. Reponen ◽  
...  
Keyword(s):  
Airborne Microorganisms ◽  
And Control ◽  
Measurement And Control
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