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radio lobe sound disk t p optical light cone The Vision *) see e.g. A. Ringwald ,ARENA 2005 Build ~100 km 3 hybrid detector to: Confirm GZK cutoff ! Do physics with extremely high energy cosmic neutrinos *) - astrophysics - E > 10 16 eV : study origin of cosmic rays - (AGN’s, black holes, GZK cutoff, …) - particle physics - E > 10 18 eV : study neutrino cross section (sphalerons, mini BH, strong ,…) - cosmology - E > 10 21 eV : study relic neutrino background radiation ( UHE absorption at CBR )
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radio lobe

Dec 31, 2015

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Seth Padilla

~ km. sound disk. p. t. radio lobe. The Vision. Build ~100 km 3 hybrid detector to: Confirm GZK cutoff ! Do physics with extremely high energy cosmic neutrinos *) - astrophysics - E > 10 16 eV : study origin of cosmic rays - (AGN’s, black holes, GZK cutoff, …) - PowerPoint PPT Presentation
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Page 1: radio lobe

radio lobe

sound disk

t

p

optical light cone

The Vision

*) see e.g. A. Ringwald ,ARENA 2005

Build ~100 km3 hybrid detector to:

Confirm GZK cutoff !

Do physics with extremelyhigh energy cosmic neutrinos*)

- astrophysics - E > 1016eV : study origin of cosmic rays - (AGN’s, black holes, GZK cutoff, …)

- particle physics - E > 1018eV :study neutrino cross section (sphalerons, mini BH, strong,…)

- cosmology - E > 1021eV : study relic neutrino background radiation (UHE absorption at CBR )

Page 2: radio lobe

Acoustic R&D in IceCube 2002 2003 2004 2005 2006 2007

start development of glaciophones

test in lab and at accelerators

calibration of sensors and transmitters

constructionand test of

SPATS Firs

t S

PA

TS

dep

loym

ent

Firs

t S

PA

TS

res

ults

Improvement (S/N)ib = 50 (S/N)gb = 15

In-s

itu

tes

t st

arts

hybr

id d

etec

tor

sim

ulat

ion

Page 3: radio lobe

The South Pole Acoustic Test Setup

SPATS

3 strings deployed Jan/07+1 string deployed Dec/07

instrumented depth:80m - 500m

per string: 7 sensors, 7 transmitters

string-PC: digitization, time-stamp, monitoring (p, T)

master-PC: process steering, GPS data storage data transfer via satellite

Page 4: radio lobe

The Four SPATS Goals

Get information about:

1.) Sound speed: what is the sound speed value?is it depth dependent (= refraction?)

2.) Transient events:are there transients events?what are their features (rate, sources)? could they be a significant source of background?

3.) Noise:what is the noise level?which energy threshold does it correspond to?

4.) Attenuation coefficient:never measured up to know, only models are known

is it depth dependent?is it frequency dependent?

Needs time information

Needs amplitudeinformation

Page 5: radio lobe

Sound Speed Results

bbb

paper submitted to Astroparticle Physics

First observation

of shear waves

in SP ice!

vp(375 m) = 3878 ± 12 m/s

vS(375 m) = 1976 ± 8 m/s

Page 6: radio lobe

Absolute Noise Level Resultσ

(V)

σ increaseafter deployment

17 Jun 0824 Dec 07

IceCube drilling

SPATS:

320 m

400 m

500 m

σ(V

)

σ increaseafter deployment

17 Jun 0824 Dec 07

IceCube drilling

SPATS:

320 m

400 m

500 m

σ(V

)

σ increaseafter deployment

17 Jun 0824 Dec 07

IceCube drilling

SPATS:

320 m

400 m

500 m

DS7-2

500 m

GaussianDS7-2

500 m

DS7-2

500 m

DS7-2

500 m

Gaussian- Gaussian- Stable- ≤15 mPa

Page 7: radio lobe

RW07/08

RW06/07

AM-RW

RW05/06

- more than one year continous data taking

- no surface noise detected

- hear 4 steady sources and at least 8 drill holes during re-freezing

- x-y resolution depends on depth and location with respect to detector typically better than 10 m

- no noise from unknown sources with present trigger conditions

Transient Noise Events

Page 8: radio lobe

Energy from the time domain

• Use pinger data

• 47 independent measurements

(from 49 combinations available)

• Weighted mean value and error:

α = 3.21+/- 0.56 10-3 m

λ ~ 312+/- 64 m

• No significant depth dependence

• No significant frequency

dependence up to 30 kHz

1 example channel

xxx

Page 9: radio lobe

SPATS Status Summary

Mission accomplished to ~95% :

- 1) Speed of Sound + Refractionspeed of sound constant below 200 mno refraction

- 2) Sound Attenuation Length

λ = 300+/- 100 m, factor 30 smaller than expected

still to measure: frequency and depth dependence possible explanation: larger influence of scattering

- 3) Absolute Noise Level

gaussian and stable≤ 10 mPa ( with reasonable assumptions)

- 4) Transient Signal Rate

small and until now all from identified sources

easy to separate from neutrino signal

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