Pyhäsalmi (site review) W. H. Trzaska on behalf of the Finnish LAGUNA team

 125 km 2 of the lake (Pyhä-järvi = Holy-lake)  6000 inhabitants around the shores 60 % in Pyhäsalmi and Ruotanen 60 % in Pyhäsalmi and Ruotanen The deepest mine in Europe The deepest mine in Europe  In 1993, after administrative decision, Pyhäjärvi became the 5 th largest town in Finland (by area)! Located close to the geometrical center of Finland; Half way between Jyväskylä and Oulu

Productivity of the Pyhäsalmi mine

EMMA Experiment with MultiMuon Array - a cosmic ray experiment located in the mine

50 m 1-layer 3-layer Parking etc. 10 m EMMA (at the depth of 75 m)  50 m 

CUPP Surfrace Lab

CUPP Surface Lab

What is required of a LAGUNA site?  Quality of the rock  Ready infrastructure  Low background from nuclear power plants (essential for geo- and supernova diffusion neutrinos)  Seismic stability  Presence of scientific activity on site  Experienced industrial partner

Bedrock zones on Earth:  Red: very old bedrock, hard crystalline rock usually very good usually very good  Green: mobile belts (mountains, etc.), hard rock fair / variable fair / variable  White: sedimentary covers (soft rock) often bad often bad

Seismic levels

Pyhäsalmi mine

This tunnel would be extended 500 m to the proposed LENA site

Dry, room temperature conditions at the 1400m level (below the ground)

Samples drilled from the LENA tunnel

All 3 LAGUNA detectors could be placed in Pyhäsalmi

All caverns are within mine territory! MEMPHYS GLACIER

Nuclear power plants in Europe (2008)

Reactor neutrinos Fuel composition: 235 U, 238 U, 239 Pu, 241 Pu Reactor: -Produces electron antineutrinos -Production rate: ~2e20 GW -1 s -1 -prop. to thermal power Propagation through the Earth -Neutrino oscillation -Matter effects negligible Detection: -via inverse  -decay (E thr ≈ 1.8 MeV) Background for geo- and supernova diffusion neutrinos

Neutrino Background from Power Plants based on 2008 data Measured spectra of reactor neutrinos for U-235,Pu-239 and Pu-241 were used. For U-238 calculated spectra were used. Event rates were calculated for a KamLand-type scintillator det.

Olkiluoto 3 (to open in 2012) EPR (European Pressurized water Reactor) 4.3 GW Thermal 1.6 GW Electrical

Geo- luminosity of the Earth U-238: Total: 6.65 Above E thr : 0.43 Th-232: Total: 5.30 Above E thr : Luminosities [x /s ]

Effect of reactor neutrinos on Geo-neutrino background Geo -window U + Th: MeV U only: MeV

Rockplan Ltd – Finnish industrial partner Underground coal storage for Helsingin Energia, m3 District cooling station for Helsingin Energia, m3 SALMISAARI underground coal storage

The underground silos are each 65 m-high x 40 m-diameter with circular plan cross-section. The volumetric capacity of each silo is m3. The Salmisaari coal transport tunnel will be re-equipped to charge the silos and a newly-mined conveyor retrieval tunnel will be used to discharge the coal. SALMISAARI underground coal storage

Summary: Phyäsalmi fulfills all LAGUNA requirements  Quality of the rock (the best)  Low reactor background (the lowest)  Low seismic activity (the lowest)  Ready infrastructure (all in place)  Clear legal status (signed MoU; all excavation within the mine area)  All LAGUNA detectors can be located in Pyhäsalmi (the only site with this distinction?)  Experienced industrial partner (Rockplan Ltd.)  Competitive excavation & operation costs (yes!)  Local support (enthusiastic!)

Thank you for your attention! ν

Backup

Reactor background vs. calculated Geo-neutrino flux [events/a/kton] (1.8 – 3.3 MeV)

What can be deduced from muons registered underground? 50 GeV cutoff  Energy of the initial CR particle Muon density at the core Muon density at the core  Approximate Z (but not on the event-by-event basis) Lateral distribution Lateral distribution

Example of muon distribution induced by a 4 PeV proton

Simulated change of p / Fe ratio from 80/20 to 20/80 reconstructed by EMMA after 12 months running