On shift: Bettoni, Pallavicini

Continued data taking at Ecm = 3615 MeV (etac prime search).

The only problem we had was a sudden drop in instanteneous luminosity,
which might have been due to the presence of liquid H2 in the nozzle
(see note by Marco in the logbook). This occurred twice, and both times
it was fixed by warming up the nozzle. The problem only occurred when
we were running in constant luminosity mode, so we switched back to
constant density.

We strongly suggest NOT to run in constant luminosity mode until the
problem is understood.

Summary of data:

run 856   203 nb-1  (started during the previous shift)
run 857   201 nb-1
run 858   207 nb-1
run 859   in progress

Grand total (so far) at this energy (runs 855-858): 824 nb-1

Diego and Marco