FDC Cathode Tension
Measurements of the full size prototype
A prototype built of kapton with a 5 µm copper layer, stripes 5 mm wide
with a 6 mm pitch was stretched very strongly. The measurement results
are presented on the next plot. A set of copper rings 86~mm OD was placed
at the foil center and the foil sagging was measured at different radii.
The plot demonstrates a systematic dependence of the result on the radius, of about 4%.
The measurements with different weights are consistent within 1%, apart from one
point, which must be an error of the particular measurement (the laser moved?).
The foil elongation perpendicular to the strips was measured to be about 0.33%.
The foil was left stretched for several days. A new measurement indicated
a drop of tension of about 10%.
Measurements of a 1/2 size prototype
Spreadsheet with measurments results
E-Mail :
gen@jlab.org
Last updated: Dec 03, 2008