Mapping of the profile 1 02/02/2003
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.
This acquisition is very time dispending, than as the above plots suggest we acquire in coincidence only a restricted zone
which would be critical. Then we decide to acquire the zone between strip 25 to 70 and between wire 2 to 7. Below we show
the plot obtained with the coincidence acquisition.
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 2 of
the same tube.
