The Matter and Radiation from the Universe features a different kind of infrastructure. There are remote observatories and space-borne detectors for cosmic radiation, a huge electron spectrometer, and underground detectors for extremely rare events. In particular:
- The Pierre Auger Observatory is the largest detector array for ultra-high energy cosmic rays. It is located in the province Mendoza in western Argentina. The observatory covers 3,000 km2 with 1,660 water-Cherenkov detectors and 27 fluorescence-light telescopes. The Pierre Auger Observatory receives contributions from 95 institutes in 19 countries. KIT has a pivotal role in the construction, operation and scientific exploitation of the Pierre Auger Observatory and is one of the most visible member institutions. In 2013, KIT became Executive Financial Institution (previously at CERN) and the Auger Project Management Office (previously at Fermilab). The Auger Collaboration has about 280 members and 190 doctoral researchers; 193 PhD theses have been completed within the project since 1999. The construction of the baseline detector configuration was finished in 2008 within budget (US$ 54M spent out of US$ 55M planned cost as of 1999); the German share was about 20%, of which two-thirds originated from the Helmholtz Association. The national partners of KIT are the universities RWTH Aachen, Hamburg , Siegen, and Wuppertal.
- KCDC is a software and data infrastructure, which provides open access to the research data collected by the international KASCADE and KASCADE-Grande cosmic-ray experiments during the last 16 years. The initial data release will comprise of more than 400 million cosmic-ray events in about a terabyte of data volume. In this way the public scientific harvest is made possible beyond the lifetime of the experiment — a novelty in the entire research field of astroparticle physics, likewise in neighbouring fields like nuclear or particle physics.
- IceCube is by far the largest operating neutrino telescope with an instrumented volume of about 1 km3 deployed at the geographic South Pole in the Antarctic ice shield at depths between 1,450 m and 2,450 m. The detector is running smoothly and can provide unique data on high-energy astrophysical and atmospheric neutrinos for many years to come. IceCube is operated by a multi-national collaboration. Germany is the second-biggest contributor to IceCube and DESY is the leading European institution. DESY is also home to the second-biggest IceCube group worldwide, and accounts, together with the eight participating German universities, for about 30% of the authors in the IceCube collaboration. In addition, DESY provides the European TIER-1 centre for IceCube data. With IceTop, part of IceCube, a first extension to an international research infrastructure has been taken. IceTop detects air showers on the ice surface and can therefore help cross calibrate the two detectors and measures cosmic-ray composition using IceCube as a huge muon detector. Various other extensions of this unique detector, to lower and to raise neutrino energies, are considered for the next few years to exploit fully its considerable science potential.
- H.E.S.S. is a system of Cherenkov telescopes observing gamma rays in Namibia. It consists of four 12-m telescopes (H.E.S.S. I, operational since 2004) and one 28-m telescope (H.E.S.S. II, operational since 2013). With an energy range of about 250 GeV to 50 TeV, H.E.S.S. I discovered most of the currently known sources and has played a major part in the boom of gamma-ray astronomy during the past decade. The inner galactic plane was systematically scanned for more than 2,500 hours and revealed many known and unknown cosmic particle accelerators. The scan data are still delivering many science results which is likely to continue in the coming years. The H.E.S.S. II telescope reaches a threshold as low as 30 GeV. To take full advantage of this low threshold, the electronics of the 10-year-old H.E.S.S. I cameras are being upgraded for operation with the high data rate that H.E.S.S. II imposes. The upgrade will be finished in 2015 and enable optimum use of the first hybrid Cherenkov telescope for a few more years before CTA will outperform H.E.S.S. DESY is a major contributor to the upgrade and will exploit H.E.S.S. science data as well as using it for tests and preparation of CTA.
- KATRIN with a 70-m-long beamline is a unique apparatus to measure the electron neutrino mass in a model-independent way using the kinematics of tritium beta decay. Its design sensitivity of 200 meV/c2 will be reached after three full years of data taking and will allow us to test degenerated neutrino mass models and the role of neutrinos as hot Dark Matter. KATRIN is currently under construction at KIT. The experiment requires an ultra-luminous molecular tritium source, which is provided by the European Karlsruhe Tritium Laboratory (TLK). TLK is a facility for processing tritium that approaches the industrial scale; it holds a license to handle up to 40 g of tritium and also serves for the nuclear fusion programme. The current site inventory is 25 g of tritium, which is processed with an extensive infrastructure with an area of 841 m2 for experiments. TLK is a unique civil laboratory and has the specific skills to handle the necessary throughput of 10 kg of tritium per year in a closed loop for KATRIN.
- EDELWEISS is a direct dark matter (DM) search experiment located at the LSM underground laboratory in the French Alps. It utilises an array of Ge monocrystals cooled to a 18-mK operating temperature to search for nuclear recoils originating from elastic collisions of galactic DM particles. In its third phase, the experiment will house up to 40 bolometers with a total fiducial mass of 24 kg, making it the largest cryogenic bolometer array in operation. EDELWEISS is anticipated to acquire data until 2016. Its detector technology is a vital input for the next generation of cryogenic DM experiments (EURECA/SuperCDMS).
Besides the larger activities above, there are a number of smaller projects with involvement of Helmholtz scientists. VERITAS and MAGIC are two operational Cherenkov telescope systems in which DESY is involved, each through a Young Investigator Group. Both telescopes have recently been upgraded and now exploit their improved sensitivity. KIT is strengthening its engagement in the Alpha Magnetic Spectrometer (AMS) onboard the International Space Station (ISS).
In the topic Matter and Radiation from the Universe we plan for substantial extensions of existing facilities (Auger, IceCube), construction of a major new facility (CTA), and for an important milestone towards a 1-ton DM detector (EURECA/SuperCDMS).
- Auger upgrade (Auger2023): To improve the composition measurement at the highest energies, the Auger Collaboration proposes to enhance the electron/muon separation capabilities of the existing surface detector stations. This will be accomplished either by adding dedicated scintillators or resistive-plate chambers, or by introducing a horizontal segmentation in the water Cherenkov tanks. Data readout of the enhanced surface detector stations will be facilitated by replacing the current readout electronics by modern state-of-the-art electronics providing three times faster sampling, a significantly enhanced dynamic range, and enabling enhanced trigger and monitoring capabilities. KIT proposes to use its expertise in readout electronics to become a key partner in the readout system in close collaboration with international partners. The combination of new electronics and an additional detector system is considered to be the fastest and most cost-effective way to obtain the required composition information on a shower-by-shower basis in the energy range of the flux suppression. The enhanced Observatory, to be operated until 2023, will enlarge the dataset available by more than a factor of two by 2015, and will yield total of about 430 events above E =1019.7 eV with zenith angles up to 80°. Presently, five options for augmenting the surface detector stations are under consideration and dedicated R&D is being pursued. It is foreseen to continue R&D and data taking with prototypes in the field until June 2014. Based on these results, a selection will be made and a TDR be provided shortly afterwards. Construction will start immediately and operation of the upgraded Observatory is expected to start not later than 2017 with data taking continuing into 2023. KIT has demonstrated in the past its ability to construct large detector components for use in the Argentinian pampa. The institutes at KIT are ready to assume significant responsibility in the construction of major detector components. In parallel, the Observatory is used for developing new technologies in detecting high-energy cosmic rays, where the activities are bundled within an ASPERA supported R&D-project, AugerNext. KIT is coordinating AugerNext.
- IceCube upgrades (PINGU/IceCube++): The aim of the upgrades is to develop the IceCube observatory into a multi-purpose infrastructure for astroparticle physics at the South Pole. The Precision IceCube Next Generation Upgrade (PINGU) is an extension to IceCube to reach a very low energy threshold. With 20-40 new strings, a core with a very high density of photodetectors is formed in the centre of IceCube which could provide an energy threshold of a few GeV. That puts the study of the so far unknown neutrino mass hierarchy within reach of the IceCube observatory. PINGU could possibly be realised on a very short timescale (within this PoF period) and at a small fraction of the cost that a dedicated beam or reactor experiment for the same purpose would cost. A letter of intent and a detailed proposal are currently being written. Germany and DESY would be the biggest partners outside the US. A complementary extension project, denoted here as IceCube++, is the substantial extension of the instrumented volume by an order of magnitude, in comparison to the current instrumented volume of about 1 km3. Such an extension will allow the detailed study of the origin and the properties of the astrophysical neutrino flux in IceCube. Substantial technological and design challenges exist for IceCube++ that need to be met by a coordinated national and international R&D effort. The goal of DESY is to take a leading role among the non-US groups in the design studies and the technology developments for IceCube++ during the PoF 3 period that will result in a formal proposal for the construction of this extension before the end of this PoF cycle.
- CTA: The Cherenkov Telescope Array will be by far the world's most sensitive and most versatile gamma-ray detector. With 150 telescopes of three sizes (4 m, 12 m, 23 m diameter), distributed over 10 and 1 km2, respectively in the southern and northern hemisphere, CTA will cover the energy region from about 30 GeV to 300 TeV with unprecedented sensitivity, at least a factor 10 better than any of the existing gamma-ray observatories. Through large fields of view and multiple images recorded of each event, the angular resolution will improve by at least a factor 5-10, the energy resolution will be below 10%, and the survey capabilities will increase by about a factor 400. The sensitivity of CTA for short timescale events (<1 day) and at low energies (<100 GeV) will be 3-4 orders of magnitude (!) better than Fermi can achieve, with huge potential for flaring objects and GRBs. CTA can observe the full sky, and operate with subarrays to monitor various objects at the same time. For the rst time a Cherenkov observatory will be run as an open, proposal-driven observatory. CTA is currently in the pre-construction phase with prototypes being built and tested, and the production techniques being refined and tuned for high reliability. CTA is being pursued by more than 1,000 physicists and engineers from 28 countries and has received very favourable rankings on the ASPERA, ASTRONET, ESFRI and many national roadmaps, as well as in the US decadal review. In 2013 CTA was put on the BMBF roadmap. The site decision is expected in early 2014, construction will start in 2015, deployment of telescopes on site begin in 2016, science operation commences in 2017 and construction will be completed by the end of 2019. DESY is a major player in CTA, currently leading design, production and system integration of the medium-sized telescope (the workhorse of CTA providing the best sensitivity in the central, TeV energy region), designing the array and telescope control and data readout for the whole array, and optimising the array con guration and analysis procedures through extensive Monte-Carlo simulations. DESY will also bid to host the CTA headquarters in Zeuthen. CTA will be the major astroparticle physics project at DESY, bene ting from the considerable expertise in gamma-ray astronomy gathered at DESY. Scientists and engineers at DESY will be working closely together with two Max Planck Institutes and nine German universities, but also with numerous international partners.
- EURECA/SuperCDMS: The phased, international programme of direct DM search using up to 1 tonne of cryogenic bolometers is part of the ASPERA European Astroparticle Physics Roadmap. In its next phase, an array of a total mass of several hundred kilograms is envisaged, being installed in the SNOLAB underground laboratory in Canada or at LSM in the French Alps. A close cooperation between European and American groups has been established to develop the most effective setup. A unique feature of cryogenic bolometers is a multi-target, low-threshold WIMP search, complementary to experiments based on noble-gas targets. The detector technology is mature and scalable, as proven by the EDELWEISS and the SuperCDMS experiments. Such an array will be sensitive to standard WIMP masses in the 100 GeV range (with sensitivity down to cross sections of 10–47 cm2 for spin-independent interactions) as well as to non-standard scenarios such as low-mass WIMPs suggested by several other experiments. There is an excellent window for realising this infrastructure on a worldwide scale during the coming funding period, with a leading role and strong visibility of the Helmholtz Association.