Enhanced Ignition of Cold Cathode Gauges Through the Use of Radioactive Isotopes Page: 4 of 17
This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to UNT Digital Library by the UNT Libraries Government Documents Department.
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
II. THE APPARATUS
A schematic representation of the bakeable stainless steel UHV test dome is shown in
Figure 1. The dome stand is made so that fiberglass insulated panels can be put in place for
bakeouts. The cold cathode gauges used in the experiment are inverted magnetron type gauges,
with separate feed-throughs for the anode high voltage and the cathode current. The gauges were
purchased from the HPS Division of MKS Instruments.
An IBM-compatible 486 personal computer (PC) was used to acquire the test data. The
gauges were controlled by an HPS Series 937 Cold Cathode gauge controller through a serial port
of the PC. The gauge ion current was sampled using a Keithley model 486 picoammeter. The
PC communicated with the picoammeter through a GPIB interface. LabVIEW graphical
programming software was run on the PC to coordinate the experiment and log data.
III. THE EXPERIMENT
For each test configuration the dome was roughed with a cryo-sorption pump and then
baked to 250 C for -24 hrs into a turbo pump. The TSP filament was powered momentarily to
remove surface gases, and the Bayard-Alpert gauge and ion pump were turned on prior to valving
out the turbo station. When the system cooled to ambient, the TSP was flashed at -50 amps for
30 minutes. The Bayard-Alpert gauge was turned off for at least an hour before start time testing
began. Only one gauge was tested at a time, and all with the same controller, power supply, and
cable.
The goal of the experiment was to accurately record the time needed for a gauge to
establish a discharge. The ion current was first recorded, then the high voltage was turned off for
3
Upcoming Pages
Here’s what’s next.
Search Inside
This report can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Report.
M., Welch K.; Smart, L.A. & Todd, R.J. Enhanced Ignition of Cold Cathode Gauges Through the Use of Radioactive Isotopes, report, November 1, 1995; United States. (https://digital.library.unt.edu/ark:/67531/metadc865326/m1/4/: accessed April 25, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.