Centre for Underground Physics in Pyhäsalmi
Centre for Underground Physics in Pyhäsalmi or CUPP is an underground physics laboratory located in Pyhäjärvi, Finland. It is located in the deepest metal mine of Europe, the Pyhäsalmi Mine (1,444 m or 4,738 ft deep; the laboratory has sites at many levels of the mine) and uses some of the infrastructure of the mine. The laboratory is made to study neutrino-physics and cosmic radiation, as well as other subjects (ranging outside physics, like geology or biology) that benefit from the underground laboratory's unique conditions. The reason that the laboratory is underground is because in the particle physics experiments, the background radiation is a problem, which can be solved by placing the laboratory underground so that the background radiation is absorbed in the rock above.
The centre is currently (2012) hosting the EMMA experiment, and it's a candidate site for the proposed European LAGUNA-observatory. Previous experiments hosted include the cosmic-ray experiment MUG (studying the depth dependency and time-dependence of the radiation) in 2001-2003 and MUD (studying the depth-dependency of the muon flux from cosmic radiation) in 2003-2005. The laboratory is managed by a regional unit of the University of Oulu, the Oulu Southern Institute, and it has seven employed personnel and hosts visiting researchers.
EMMA
EMMA (Experiment with MultiMuon Array) is a cosmic-ray experiment taking place in CUPP and it's still partly under construction. The experiment is a joint venture of the University of Oulu, University of Jyväskylä, University of Aarhus and the Russian Academy of Sciences.
EMMA is focused on studying the composition of cosmic rays in the energy above 1 PeV-range, the so-called knee region. When a primary cosmic particle collides with the atmosphere, it decays into secondary cosmic particles creating an air shower (muons, electrons, hadrons). EMMA is able to determine the muon shower multiplicity, lateral distribution and direction of entry-measurements.[1]
The measurements are performed at the depth of 80 metres in Pyhäsalmi mine. Measurement devices consist of nine detector stations (15 m2 each) and the main part of the detectable area is covered with drift chambers.[1] The drift chambers used in the experiment originate from the DELPHI-experiment at CERN. Additionally the limited streamer tubes and plastic scintillation detectors are part of the measurement stations.
References
- ^ a b P. Kuusiniemi et al. "Underground multi-muon experiment EMMA" (2011) Astrophysics and Space Sciences Transactions, vol. 7, no. 2, Apr 2011, pp. 93–96
63°39′31″N 26°02′28″E / 63.65861°N 26.04111°E
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