UV curing of Pb/glass
Today's test of using a high-intensity UV lamp to "cure" radiation
damage (yellowing) of a Pb/glass block seems to have been a
success. The worst block (one near the beam home, row 15, col 3)
previously gave 43 ADC counts for a typical laser event on a pedestal
of 30 counts; after curing for approx 2.5 hours with the UV lamp it
now gives 115 ADC counts on a pedestal of 30, i.e. an apparent
improvement in the amplitude over pedestal of a factor of 5.
We will now proceed to try shorter (order 0.5 hour) illuminations
of the next three worst blocks before the beam is expected to come
back.
Pictures of before and after laser events are below; the block
of interest is immediately above the beam hole, on the right.
David A.
Before curing:
After curing:
