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[en] An experiment observing underground muons originating from cosmic-ray air showers is under preparation in the Pyhaesalmi mine, Finland. The aim is to cover an area of about 200-300 m², and the detector setup is capable of measuring the muon multiplicity and their lateral distribution. The detector is placed at a depth of about 85 m (corresponding about 240 m w.e.), which gives a threshold energy of muons of about 45 GeV. The detection of the multimuon events is motivated by partly unknown composition of the primary cosmic rays in the energy region of 10¹⁵-10¹⁶ eV, i.e., the knee region. In addition, by measuring only the higher energy muons of the air shower, the lowest energy muons being filtered out by the rock overburden, the data is sensitive also to the studies of the upper parts of the air shower. The experiment will be constructed mainly using drift chambers used previously in LEP detectors at CERN, but it can also be expanded using plastic scintillator detectors. The prototype detector is expected to be running in the beginning of 2006, and the full-size detector by the end of 2007

[en] An experiment to observe simultaneous, multiple muon events originating from extensive air showers is under preparation. The experiment will be situated in shallow depths in the Pyhasalmi mine in Finland, where the existing free caverns will be used. The aim is to cover an area of about 200-300 m². The detection of the multimuon events is motivated by partly unknown composition of the primary cosmic rays in the energy region of 10¹⁵-10¹⁶ eV, i.e. the 'knee' region. A prototype detector is under construction and is expected to be running at the spring 2005

[en] The results of a development of a scintillator counter with wavelength shifting (WLS) fibre and a multi-pixel Geiger-mode avalanche photodiode readout are presented. The photodiode has a metal-resistor-semiconductor layered structure and operates in the limited Geiger mode. The scintillator counter has been developed for the EMMA underground cosmic ay experiment.

[en] A new cosmic-ray experiment is under construction in the Pyhaesalmi mine, Finland. It aims to study the chemical composition of cosmic rays at and above the knee region. The array, called EMMA, will cover approximately 150 m² of detector area at the depth of 85 metres (∼240 mwe). It is capable of measuring the multiplicity and the lateral distribution of underground muons, and the arrival direction of the air shower. The full-size array is expected to be ready by the end of 2007. A partial-size array (one third of the full size) is planned to record data already at the first quarter of 2007. The array is also expected to be capable of measuring such high-multiplicity muon bundles as was observed at the cosmic-ray experiments at the LEP detectors

[en] A new cosmic-ray experiment is under construction in the Pyhaesalmi mine, Finland. It aims to study the (mass) composition of cosmic rays at and above the knee region. The array, called EMMA, will cover approximately 150 m² of detector area at a depth of 85 metres (∼240 mwe). It is capable of measuring the multiplicity and the lateral distribution of underground muons and the arrival direction of the air shower. The full-size array is expected to be ready by the end of 2007. A partial-size array (one third of the full size) is planned to record data already at the first quarter of 2007. It is also expected that the array is capable of measuring such high-multiplicity muon bundles that were observed at the cosmic-ray experiments at the LEP detectors

[en] A new cosmic-ray experiment is under construction in the Pyhaesalmi mine, Finland. It aims to study the (mass) composition of cosmic rays at and above the knee region. The array, called EMMA (Experiment with MultiMuon Array), will cover approximately 130 m² of detector area at a depth of 75 metres (∼210 mwe). It is able to locate shower cores in an area of approximately 400 m² with an accuracy better than 6 metres. The array detects underground muons and the muon multiplicity, their lateral distribution and the arrival direction of the air shower can be determined. First scientific measurements can be started during the spring 2009 with a partial-size array. The full-size array is expected to be ready by autumn 2010. The full-size array consist of two type of detectors: drift chambers and plastic scintillation detectors. Besides the composition study, it is also expected that the array contributes on the study of high-multiplicity muon bundles that were observed at the cosmic-ray experiments at the LEP detectors.

[en] A cosmic-ray experiment of new type is under construction in the Pyhaesalmi mine in the underground laboratory of the University of Oulu, Finland. It aims to study the composition of cosmic rays at and above the knee region (energy above 1 PeV). The experiment, called EMMA, covers about 150 m² of detector area, and the setup is capable of measuring the multiplicity and the lateral distribution of underground muons, and the arrival direction of the air shower. The detector is placed at the depth of about 85 metres (corresponding about 240 mwe) which gives a threshold energy of muons of about 45 GeV. The rock overburden filters out all other particles of the air shower except the high-energy muons. These high-energy muons originate at high altitudes close to the first interaction of the primary cosmic ray and they carry more information about the primary than low-energy muons. The full-size detector is supposed to run by the end of 2007