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DAFNE update
Dear Colleagues,
Dafne team succeeded in finding a good optics for both rings, and from
last night few tens of mA of electron and positron currents were
also simultaneously circulated in multibunch mode.
Nicely, in these contitions the microstrip detectors do not show to be
seriously hit.
The problems now, from the machine point of view, are:
- a strong beam-beam coupling which affects, of course, the interaction
region, and that must be reduced to produce efficiently collisions.
- the need to conditioning the machine with high current beams to
improve the ring vacuum.
As adfirmed by the machine director, in such phases there could be
some further significative radiation "spreads", due, however (... or
hopefully) to occasional unwanted beam losses and not to a systematic
several hours long period of beam tuning, as in past weeks.
Moreover, the strategy of DAFNE team is to proceed in the fastest
way in machine optimization, not requiring any information from FINUDA
apart the microstrip leakage currents. They, hence, in this phase do not
want any interference or delay from us, for instance FINUDA asking to
mantain stable circulating beams and deciding when and if to inject.
Which is equivalent to a practical impossibility, for obvious safety
reasons (unless differently decided by the responsible of individual
detectors), to switch on any detector (and expecially the near pipe
ones) until the A.D. judges the machine stable enough for that.
Such date is not far, but A.D. is not yet able to provide it sharply.
A new update will follow next Monday.
The RUN
CO-ordinator