Mapping of the profile 2 02/04/2003
In the pictures of an open profile it is possible
to see some imperfections in the coating
of the tubes. These tubes had some problem.
In order to study which are the causes of the discharge in the tube we try
to make a mapping of the coating surface of another tube. We want to study critical point
(or zones) in the tube where the discharges appear.
For this porpouse we have to find in which wire and where along the wire there
are some discharges. Initially we collect the counting rate from wires and strips independently as shown in the following plots.
In order to obtain a detailed mapping of the tube we need to acquire the rate from the coincidence between wires and strips.
For the profile 1 there was an evidence of the critical zone, then it was possible to perform a coincidence acquisition of a
restricted area. While for the profile 2 it seems that critical zones were distributed over the entire profile. Then in order
to have a detailed mapping we made the coincidence acquisition of the entire profile. The plots are shown below.
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From coincidence acquisition it should be possible to obtain the distribution of the rate for wires and for strips as
obtained from the single acquisition (shown at the top of this page). Infact the wire-rate distribution will be the sum
of all wire-rate distribution obtained in coincidence with each strip (performing a sum of the rate over the strips).
The same thing will be for the strip-rate distribution, as the sum of all strip-rate distribution obtained
in coincidence with each wire. Below we show the plots obtained with
this procedure.
The above distributions have about the same shape of the distributions obtained
from the independent acquisitions of wires and strips shown on top of this page. We have to note that the coincidence acquisition and single acquisition have been obtained at different voltages.
Now we will proceed to open this tube in order to find which are the causes of high rate in
the critical region.
A similar analysis has been done for the
profile 1 of
the same tube.
