Ice Cube string 21 performance Dmitry Chirkin LBNL

Ice. Cube string 21 performance Dmitry Chirkin, LBNL Ice. Cube collaboration meeting at Berkeley, March 20, 2005

Roundtrip time measurements Comm ADC waveforms

Previous results (FAT in DFL) just timing Laser time resolution

DOM clock stability (In-Ice) DOM clock drift calculation: 1. Using time calibration cycles t 1…tn, calculate DOM clock (relative to DOR clock) frequencies w 1…wn-1 2. Frequency drift from one pair of tcal cycles to the next is wn-wn-1 Timing resolution is best when this drift is small 3. Overall frequncy drift is wn -w 1.

DOM clock stability (Ice. Top)

COMM ADC baseline variations Baseline average, RMS

Ice. Top shower reconstruction

Ice. Top shower reconstruction (cont. )

Ice. Top Waveforms

Muon track reconstruction with string 21

String reconstruction: comparison with recoos

Event in run 463

Event in run 872

Residual time plots

Ice. Top – In-Ice coincident events

Observed channel multiplicity (Ice. Top)

Observed channel multiplicity (In-Ice)

Monolith vs. datacollector Monolith trigger condition: 8/10 hits in 2000 ns

Conclusions • Round trip time resolution (RMS) is better than 4 ns for all DOMs with crossover or centroid algorithms • All DOM clocks appear to be sufficiently stable • Zenith anlge distributions for showers with Ice. Top and muons with string 21 seem reasonable, comparison with the Monte Carlo is coming in the near future • Coincident events show excellent agreement between Ice. Top and In-Ice- reconstructed events. These events may provide more insight into the In-Ice photon arrival distributions, i. e. further constraints on the ice parameters • Monolith data is in excellent agreement with the datacollector’s full hit stream data • All hit and tcal data appears to have excellent quality!

Neutrino (? ) events

Neutrino (? ) events

Event in run 872 (March 4) Event in 3 D: • Cross your eyes (1. 5 o) • Diverge your eyes (1. 5 o)

Cross your eyes

Diverge your eyes