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Minutes of the January 29 Background Remediation video meeting

  1. The 1-week PEP-II run extension, recommended by the Background Remediation Steering committee, was officially accepted by SLAC.
  2. A. Roodman showed the plans for the DCH actions items. A post-doc, Thomas Schietinger , has started to work on these issues. The first step is to study whether a PIN-diode sensor has the appropriate sensitivity to protect the DCH electronics. If this turns out to be the case, a clone of the SVTRAD board would be used. The physical location near the electronics boxes is not easy to find, if one wants to keep a good access to the boxes. A tentative end date for this system to be in place is April 1.
  3. Concerning the other DC action items, Aaron unfortunately confirms the present limitation of 200 hits in ROM feature extraction at a sustained rate of 2 kHz. There does not seem to have a large room for improvement due to optimisation. One possible way out presently under investigation would be to recognise early in the feature extraction a background hit and discard it fast.

    It is possible to put two CAEN channels in parallel to get more max current in the first layer. Aaron will study this in more detail.

  4. Jim Olsen reported on the first very successful hand shake between PEP-II and BABAR. Congratulations to all involved! PEP-II sent injection requests that can be granted by BABAR in manual mode or in auto mode. It took between 29 and 45 seconds to satisfy this request (and similarly to restore BABAR after end of injection). Points mentioned in the discussion:

-Do not leave OVERRIDE button available on PEP-II operator side

-Hardware interlocks (T. Mattison is scheduling a meeting on Wednesday Feb 3 on that point)

-Prevent BABAR operator to swicth HV_on during injection

-Warn BABAR shifters of what is going on in auto mode

4. Carsten Hast reported of the SVT action items. The module to be exposed to radiation damage before the end of the PEP-II run is being prepared in Pisa and will arrive next week at SLAC. It will be installed near a copper beam dump . 1 shift will be needed to make the measurements. The desirability to have a RADFET installed to follow the dose received by the module was expressed. Carsten also mentioned that in his Monte Carlo study, he finds no increase in occupancy when turning B field on. This does not agree with the number reported by a scoring cylinder study performed by M. Ronan and quoted in the workshop executive summary.