March 5th 2009 SFB 676 C8-2 1

Simulation Studies for Cosmic Neutrino Detection

with IceCube++ at the South Pole

Rolf Nahnhauer

DESY

March 5th 2009 SFB 676 C8-2 2

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 )

March 5th 2009 SFB 676 C8-2 3

Milestone OneCheck capabilities of technologies at South Pole

Optical detection: excellent AMANDA, IceCube

Radio detection: probably good RICE, more to come (AURA, IceRay)

Acoustic detection: no measurements until recently

Expectations: att ~ 1-10 km

low noise

favourable refraction confirm by in-situ test

“SPATS”

bottom echo visible through 2x 2.8 km!

R. Bay, UCB, unpublished

ice depth / m

tra

ns

p.

/ a

rb.

un

its

92000 year old ash layer

nearly finished

March 5th 2009 SFB 676 C8-2 4

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

Measure: 1) speed of sound + refraction2) sound attenuation length 3) absolute noise level4) transient signal rate + source

March 5th 2009 SFB 676 C8-2 5

SPATS Status Summary

Mission accomplished to ~80% :

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

- 2) Sound Attenuation Length

300 m < λ < , needs to be improved new measurements at longer baseline transient signals

- 3) Absolute Noise Level

gaussian and stable< 10 mPa ( with reasonable assumptions) think about in-situ calibration

- 4) Transient Signal Rate

small (~100 events/day)easy to separate from neutrino signal

+++

++

+++

+

March 5th 2009 SFB 676 C8-2 6

IceCube Meeting Utrecht September 2008

1 Day Common Meeting of Radio and Acoustic groups

about future strategy

Near Term Future

March 5th 2009 SFB 676 C8-2 7

Milestone TwoDetailed simulations forGZK hybrid detector at South Pole

Detection option GZK events/year*)

IceCube 0.7

Optical 1.2

Radio 12.3

Acoustic 16.0

Optical+Radio 0.2

Optical+Acoustic 0.3

Radio+Acoustic 8.0 !!!

Opt.+Rad.+Acou. 0.1

TOTAL 21.1

Very first approach:instrumented volume ~(110 +3) km3

D. Besson et al.,

astroph/0512604

GZK neutrino flux:R. Engel, D. Seckel and T. Stanev Phys. Rev. D 64, 093010 (2001)

Calculations done up to now : - for only one neutrino flux model - without detailed input for detector - without measured target material properties

to be started

March 5th 2009 SFB 676 C8-2 8

Necessary Next Steps

- Working group and collaboration building

- Write Letter of Intent to demonstrate: scientific importance in comparison to other topics expected improvement to previous experiments time scenario and milestones

- Finish basic exploration of ice properties

- Start extensive MC studies of different detector options

- Track down number of different detector options

- Write Proposal

expand letter of intent to give detailed information based on extensive MC and hardware studies still go with flexible design plan and 2 phase structure include realistic budget plan

March 5th 2009 SFB 676 C8-2 9

Resources at DESY

Available for SFB C8-2:

Required for SFB C8-2:

scientific ass. R. Nahnhauer 10scientific ass. C.Spiering Cpostdoc J. Berdermann 5PhD Student D. Tosi (later NN) 20

Working hours /week

postdoc NN 40

+ some travel money