nuclear physics in poland 1996 – 2006

POSSIBLE LOCATION FOR THE UNDERGROUND LABORATORYIN POLANDA.Zalewska 1H. Niewodniczański Institute of Nuclear Physics PAN, KrakówFirst measurements of neutrinos from theSun in 1964 and from the supernova explosion in1987, and recent discoveries of the oscillations ofatmospheric and solar neutrinos caused that thephysics of natural neutrinos became the importantfield of studies and that the neutrino astronomywas born. It is clear that neutrinos are importantmessengers from stars. Another big but still openquestion concerns the proton decay, predicted byGrand Unification Theories aiming at theunification of fundamental forces in Nature.Achieving significant progress in both studiesrequires huge detectors on the 100 – 1000 ktonsscale, i.e. by one to two orders of magnitude largerthan the existing ones [1].At present there is no single infrastructurein the world which could host such detectors. TheLAGUNA project [2] aims at looking for thepossible localization in Europe, in agreement withthe ApPEC roadmap. Although studies of the lowenergy neutrinos from astrophysical sources andsearches for proton decay are of the primaryinterest, the localization should take into accountthe possibility of neutrino studies with acceleratorneutrino beams. One of the possible locations ofthe new infrastructure is in Poland.The pre-feasibility study of the localizationof a big underground laboratory in the Polkowice-Sieroszowice mine in Poland has been performedin the years 2004-2006. The Polkowice-Sieroszowice mine belongs to the KGHM holdingof copper mines in west-southern Poland. The siteis placed about 80 km from the airport in Wrocławand 40 km from the motor way A4 crossingsouthern Poland in the west-east direction (seeFigure 1). Its distance from CERN is about 950 km.Apart from copper ores the localgeological structure contains a layer of NaCl,which is about 70 meters thick and located at adepth of 900-1000 meters below the surface.Anhydrite layers, placed directly above and belowthe salt layer, are of comparable thickness. Thissalt has not been yet massively exploited but in thePolkowice-Sieroszowice mine a few big saltFig.1. Map showing the localization of the Polkowice-Sieroszowice site (marked with a red star).caverns were excavated in the nineties. One ofthem, almost 100 m long, 15 m wide and 15 mhigh, placed at a depth of 950 m below the surface,is shown in Figure 2. It is being used formeasurement purposes. The movements of thesalt walls have been monitored there since 1997 inorder to understand better the viscous creep ofsalt at big depths. The temperature in this cavernis about 35 0 C and the humidity is about 20%.The pre-feasibility study contained twoelements: measurements of the background due tonatural radioactivity and initial geo-mechanicalsimulations of the excavation of a huge saltcavern.Fig.2. Photo of the existing big salt cavern; inset shows anelement of the measuring system used for the long termmonitoring of wall movements due to salt viscous creep.1 Contributions: W. Pytel (KGHM Cuprum, Wrocław), K. Urbanczyk, J. Slizowski (Mineral and Energy Economy ResearchInstitute PAS, Kraków), J. Dorda, J. Kisiel, A. Konefal (University of Silesia, Katowice), M. Budzanowski, S. Grabowska, K. Kozak,J. Mazur, J.W. Mietelski, M. Puchalska, A. Szelc, E. Tomankiewicz, A. Zalewska (H.Niewodniczanski Institute of Nuclear PhysicsPAN, Kraków)37