Download - IceCube Dust Loggers
IceCube Dust LoggersIceCube Dust Loggers
Kurt Woschnagg, Ryan Bay
Physics Department, UC Berkeley
Instrumentation Session
IceCube Collaboration Meeting
Bartol, March 2004
Borehole Dust-LoggerBorehole Dust-Logger
First-generation logger(mechanically drilled hole)
Field Tested Pole-to-PoleField Tested Pole-to-Pole
A dust logger in AntarcticaA dust logger in Greenland
Record of Northern climate variations at GISP2Record of Northern climate variations at GISP2(Greenland Ice Sheet Project, 3054 meters)(Greenland Ice Sheet Project, 3054 meters)
Dust logger data
Dust in ice core
Temperature record from ice core
Motivations for an Motivations for an optical dust logger in IceCubeoptical dust logger in IceCube
Motivations for an Motivations for an optical dust logger in IceCubeoptical dust logger in IceCube
Constrain horizontal variations
Improve depth resolution of ice model Currently ~10 m using in situ OMs Volcanic ash?
Bonus science(à la RICE, acoustic detectors, etc.)
A hole in the ice is a valuable commodity
fastfast
hi-res
hi-res crucial
calibs
Dust layers dominate ice propertiesDust layers dominate ice properties
…dust inice cores.…dust inice cores.
AMANDA:Variations in
optical propertiescorrelate with…
AMANDA:Variations in
optical propertiescorrelate with…
Km-scale horizontal variations?Km-scale horizontal variations?
Siple Dome, West AntarcticaSiple Dome, West AntarcticaOver Over 60 volcanic ash layers detected60 volcanic ash layers detected
Volcanic ash at South PoleVolcanic ash at South Pole
~500 miles from SDM; altitude 3× as high
Known to exist Palais, J. M. et al.,
GRL (1992) Cole-Dai, J. et al.,
Ann. Glaciol. (1999)
Ash bands can improve simulationsAsh bands can improve simulationsThin, extremely absorbing
ash bands introduced“Standard” ice description
Analysis by Marek Kowalski
Zcog = depth (z) of center-of-gravity for reconstructed muon tracks
Simulation of volcanic ash layers in bubbly iceSimulation of volcanic ash layers in bubbly ice
MC Data
Strawman IceCube dust logger designStrawman IceCube dust logger design
TechnicalsTechnicals
Continuous laser, signal integration: 10 ms – 1 s Sampling rate: ~50 Hz Located at bottom of string, between weights (TBD) Centered in hole, unobstructed view 4 service-wire pairs from lowest breakout (@DOM59)
Connectors TBD Readout during deployment (only)
→ slipring connection Stand-alone DAQ or Integrated into deployment/drill
IssuesIssues Irregular walls will degrade data quality Dust log requires real-time depth readout
→ Pick-off deployment pressure
Must not jeopardize deploymentTime limitNo retrieval once drop (lowering!) begins
Slower rate (factor 2) through instrumented ice? Normal drop speed (15m/min): ~1 hour
Plan for IceCube dust loggersPlan for IceCube dust loggers
Total of 9 loggers- one in each of the six corners
- three inside array
(one of these at AMANDA center for cross-calibration with AMANDA dust profile)
First dust logger in first season (04/05, PY03) Then two per season Built & operated by UCB (at least first few)
ConclusionConclusion
Dust loggers are crucial calibration devices
Need to get one in early
Have experience, will travel
Simulation of volcanic ash layers in bubbly iceSimulation of volcanic ash layers in bubbly ice
MC Data