ORNL/IAT ARMATURE DIAGNOSTICS DEMONSTRATION TEST REPORT 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:
(514 nm) of La2O2S:Eu. The decay time, tau, is displayed. The temperature is determined
from a calibration programmed into the code and displayed. If there are interfering effects
from bright backgrounds, motion effects, or other concerns, the signal is post processed using
a spreadsheet program (Sigma Plot or Excel, in practice) and then the corrected signal is
returned to the labview program in order to ascertain temperature.
The phosphor chosen for this test has a high degree of temperature sensitivity but a limited
range. It turned out to be the correct choice for this test. For future testing where
temperatures and velocities will be higher, an alternate material may be required. This is
discussed in the conclusions.
Results
Timing and Velocity Measurement. Figure 7 shows two signals produced by the timing
fiber. The blue trace is the signal from an armature and it is typical of most of the shots.
There were no markings or alterations purposely made to the armature to affect the reflected
light. The sharp rise is produced by the leading edge of the armature moving into the field of
the timing fiber. There are some fluctuations of the signal as the surface moves along.
Evidently this is due to superficial irregularities of the surface. The signal falls precipitously
as it moves out of the field of view of the fiber. Table 1 below shows the results of velocity
measurement for a number of shots.
In order to investigate another means for attaining well-defined timing and precise velocity
measurement, two distinct grooves were purposely filed into an armature. It is the one seen
in the inset photograph in figure 7. The black trace in the figure is the reflected signal from
this armature. The two grooves produced pronounced dips in the reflected signal, the desired
effect. This is therefore an effective optical encoding method. Clearly, with some more
thought given to the optical illumination and to precision machining, this has the potential for
larger scale rail gun implementation.
Table 1 Shot velocity
Shot # Velocity m/s
37 60
38 76
39 67
41 67
42 21
43 51
44 53
45 72
46 76
47 80
48 88
49 19
51 284
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.
Allison, Stephen W; Cates, Michael R; Goedeke, Shawn; Crawford, M. T.; Ferraro, S. B. & Akerman, A. ORNL/IAT ARMATURE DIAGNOSTICS DEMONSTRATION TEST REPORT, report, March 1, 2005; [Tennessee]. (https://digital.library.unt.edu/ark:/67531/metadc902304/m1/4/: accessed April 24, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.