1. Azriel Goldschmidt AMANDA/IceCube Collaboration Meeting Laguna Beach, CA March 2003 String-18 Progress and Plans

2. Fast Communications –changes to firmware and software done –35 DOMs can now (finally!) handle 350 kBaud –Upgrade to 525 kBaud or higher possible –Now working on surface DAQ bottlenecks Data compression/bandwidth studies with string-18 waveforms, relevant for string-18 and IceCube -see Klaus H.’s talk- –Plan for software data reduction/compression running on ARM –Remains to be seen if ARM can handle the load

3. String-18 Progress and Plans (cont…) Improved understanding of waveforms: discriminator noise, pedestal pattern, ringing, etc, by Seckel@Bartol Improved understanding of time correlated light in DOMs -see Klaus H.’s other talk- –This has implications for both String-18 and IceCube Surface DAQ “bug” fix during 02/03 season “thanks Holger!” –Time calibration to global clock to < 3.5 ns Tested VLF antenna effect on communications

4. New Flasher Runs –for Kurt & Co (is it still bumpy?) –for further understanding of timing/software trigger New LED trigger capabilities (for PMT transit times and gain calibration) String-18 Progress and Plans (cont…)

5. Example of a Flasher Event: Times and Waveforms ATWD 1.8 ns/sampleFADC 60 ns/sample

6. Another Flash

7. Ringing… Waveform Studies: Lots of progress from a fresh look by Seckel

8. Waveform Studies: Lots of progress from a fresh look by Seckel (cont…) Discriminator noise…

9. Waveform Studies: Lots of progress from a fresh look by Seckel (cont…) Discriminator noise, distinct from pedestal pattern...

10. String-18 (Digital) VLF immunity

11. Plans IceCube effort has currently higher priority, but if resources are allocated: First: remove surface DAQ data bottlenecks Second: implement software data reduction Third: Implement online trigger (string processor implied)

12. ATWD and ADC waveforms Example: 3 photons in 2 microseconds ATWD0 High GAIN 1.7 ATWD1 Low Gain 1.7 ATWD2 Nothing 1.7 ATWD3 Clock 1.7 ADC 60 7.7  s 217 ns ns/sample Time Sample Number

13. Muon Data: Checking timestamps with coincidences from consecutive OM’s T (DOM N) T (DOM N+1) DeltaT = T (DOM N) - T (DOM N+1) Zoom around [-1,+1]  sec : Mean at ~ -24 nsec Consistent with expectation for downgoing muons 12 m

14. Example Muon Event #1 Only first hit in each OM shown Down flow of light Late hits consistent with light scattering Late Hit