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