1. Astroparticle Physics at DESY IceCube CTA Recommendations

2. IceCube optical Construction finished in December 2010 86 strings deployed (2005 to 2010) inauguration April 28th, 2011 Excellent performance: very low failure rate of OMs 98% up-time During installation time: accumulated exposure ~ 2 cubic kilometer year

3. IceCube – further installations Continuation of R&D efforts still possible In ice radio antenna stations for ARA  GZK neutrinos NaJ-detector in ice  evaluation for direct dark matter search acoustic components  acoustic ice properties

4. CTA Germany has a leading role in CTA DESY is a strong partner in CTA and gives important support to German CTA groups; DESY has high visibility in CTA DESY contribution: mid size telescope design and prototype array operation centre electronics analysis and computing Pre-prototype has been set-up Prototype expected until end 2011

5. general Application for a „Helmholtz Alliance on Astroparticle Physics“ proposal submitted December 2010 evaluation in April 2011 was positive has to be approved be the Helmholtz Senat Berlin-Brandenburg-Cluster is etablished (Universität Potsdam, Humboldt- Universität Berlin, DESY-Zeuthen) Markus Ackermann + 1 Postdocs + 1 Doktorand

6. Recommendations DESY should take a leading role in the coming Helmholtz Alliance IceCube: DESY should extensively take part in the physics harvest CTA DESY should keep its strong hardware involvement DESY should strengthen its simulation and physics involvement