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