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String 21 Flashers in Amanda. Dom 23 flasher run from April 9th. String 21 Flasher Events -- merging. Analysis details: Monolith (software trigger) not run on flasher data. Run offline Monolith Multiplicity trigger -- 10 or more DOMs in 5000 ns time window
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String 21 Flashers in Amanda Dom 23 flasher run from April 9th David Hardtke - UCB
String 21 Flasher Events -- merging • Analysis details: • Monolith (software trigger) not run on flasher data. Run offline • Monolith Multiplicity trigger -- 10 or more DOMs in 5000 ns time window • Previous results had cut of 23 or more DOMS • L1 filtered AMANDA data from pole (still looking for unbiased data set) • Nobody seems to know what L1 filter does exactly • Used John Pretz merging routine (in SVN, works with version 1-06 of offline software) • Search for common IceCube/AMANDA triggers within -20 s < t < -5 s. 100% official IceCube software David Hardtke - UCB
Data Analyzed David Hardtke - UCB
Geometry DOM 12 DOM 23 DOM 32 Stuck String David Hardtke - UCB
Local Ice Dust logger data DOM 32 DOM 23 David Hardtke - UCB
Merging Rates • Most data I will show is from April. Flasher 23 run at high rate: • Nominal rate is 610 Hz • Monolith trigger rate is 611 Hz • Rate of common IceCube/Amanda triggers is 103 Hz • 28480 merged events from runs 2984 and 2985 • Number of IceCube Oms/Event unaffected by AMANDA coincidence requirement David Hardtke - UCB
GPS Synchronization • Measure Trigger Time difference • No correction for physics (trigger def, scattering, etc.). Absolute offset not understood • UPPER LIMIT on GPS synch is 400 ns • Stable over 10 minute period David Hardtke - UCB
Which strings are hit? Flasher 23 • Mean # of AMANDA OMs ≈ 50 • Biased sample • AMANDA online filtering • Will repeat with unbiased AMANDA/String 21 selection Stuck String David Hardtke - UCB
Z-position of hit AMANDA OMs Flasher Location Flasher 23 David Hardtke - UCB
Distance from flasher to AMANDA OM David Hardtke - UCB
Distance from flasher to AMANDA OM ≈ 103 Hz David Hardtke - UCB
Newer Runs • Recent runs use a lower flasher rate • Nominal Rate -- 10 Hz • Mult>9 rate from monolith -- 11.8 Hz • “Flasher Events” (Mult > 17) -- 9.7 Hz • Flasher Events that trigger AMANDA -- 0.01 - 0.04 Hz Something strange here -- the coincident rate has dropped from 1/6 to 1/1000. Could be data OR sieglinde pole filter David Hardtke - UCB
Flasher Event Isolation Flasher Events Flasher 32 muons David Hardtke - UCB
Strings Hit by Flasher 32 David Hardtke - UCB
Z position of hits from flasher 32 Z in IceCube coordinate (m) David Hardtke - UCB Flasher 32
Warning-- DOM Turn On David Hardtke - UCB
DOM flasher LED configuration David Hardtke - UCB
Conclusions • Able to see String 21 flashers in AMANDA • True for Flashers 12, 19, 23, and 32 • Flasher is very bright (visible 400 m away) • AMANDA and IceCube GPS clocks are synchronized to better than 400 ns David Hardtke - UCB
Wish List • To get meaningful results: • Need unfiltered AMANDA data from pole (request submitted to black hole [help@icecube.wisc.edu]) • Need more data (higher repetition rate/longer runs) • IceCube data without local coincidence (compare light propagation in horizontal and vertical directions) • Some software improvements (working with Pretz) David Hardtke - UCB