1. WP F/L Detection Unit Mechanical Structure and Deployment R. Papaleo 130/03/2011

2. WP F/L Content Requirements Lessons learned from test deployments Compact deployment method Design of storey Design of detection unit Design of vertical e/o cable Summary and conclusions 30/03/20112

3. WP F/L Requirements (TDR) Deploy a detector With 320 or 640 Detection Units – 320 DU after convergence towards single solution With a height of about 900 m Time constraint: Within ~ 4 year 30/03/2011 3 Physics simulations Compact deployment!

4. WP F/L Compact deployment Concept: Stack storeys with DOMs in a compact structure Deploy the structure to the seabed Release the structure to unfurl to its total length  Allows deployment of DUs with horizontal extent – Only one crane required  Allows time efficient deployment: – Storage of multiple DUs on a single deployment vessel, thus multiple Dus deployed per sea cruise – Fast descent to seafloor – Less dependency on bad weather conditions 30/03/20114

5. WP F/L Antares (not compact) Concept for 640 strings Concepts for 320 towers Several test deployments Experience acquired regarding: rope and cable management unfolding procedures material choices buoyancy drag calculation models sea procedures

6. WP F/L Deployment of a multiple stack DU 30/03/20116

7. WP F/L Lessons learned Compact deployment is feasible Diameter cable/ropes have large influence on drag of the top When structure is not self-buoyant: – Large top buoy required In case of buoy failure detection unit lost When structure is self-buoyant (distributed buoyancy): – Failure of buoy less dramatic – Constant tension on the ropes during unfurling important Dimensions and weight in air of the structure constrained by possibilities of deck-handling 30/03/20117

8. WP F/L Requirements more specific Decision end 2010: Deploy a detector with 320 Detection Units with: – 3D configuration – 20 storeys, 6 m long, DOM at either end (DOMBAR) – Distance between storeys 40 m Deploy these 320 DUs within ~4 year Deploy a prototype Detection Unit (PPM-DU) 30/03/20118

9. WP F/L Cable storage Buoyancy DOM  e/o backbone cable spirals around tensioning rope 4 ‘crossing’ tensioning ropes allow 3D structure of detection unit KM3Net DU design concept Test with spiraling cable

10. WP F/L It’s a bar with a DOM at either end Distance between DOM and storey structure > 30 cm Stores 4 tension ropes, 2 e/o backbone cables (length ~40 m) Storey is buoyant KM3Net DU storey design concept 30/03/201110 Buoy Spiral backbone DOM

11. WP F/L Storey packaging 5 columns x 4 layers Dimension: 5810 x 2340 x 2270 mm Fits within ISO container 30/03/201111

12. WP F/L Hydrodynamic behaviour CharacteristicsValue Rope OD (4x)4 mm (max load = 2180 kg@rope) e/o backbone cable (2x)6.35 mm (oil filled) Top Buoynacy1.000 N Bar Buoyancy500 N Total Buoyancy10.000 N Anchor3.600 kg in air Total Transport weigth6800 Kg Totale weight in sea6100 Kg Top drift120 m @current v = 0.30 m/s 30/03/201112

13. WP F/L DOM suspension Protects DOM equator Leaves front of PMTs free Allow shrinkage of glass sphere under high pressure (~2 mm) First prototype ordered 30/03/201113

14. WP F/L Vertical e/o backbone cable The main functions of the vertical backbone cable are: – To provide electrical power to all DU sensors (DOM + satellite sensors like hydrophones) – To provide communication to/from between DU sensors and the shore station It must allow optical point-to-point connection between DOM and shore station electronics It must be flexible enough to allow compact stacking of the storeys 30/03/201114

15. WP F/L 400V switch 400V/12V 12V/ 1-5V DOM 20 400V/12V 12V/ 1-5V DOM 19 400V/12V 12V/ 1-5V DOM 2 400V/12V 12V/ 1-5V DOM 1 400V 0V VEOC Seafloor network DOM 20 DOM 19 DOM 2 DOM 1 Downstream 625Mbps Upstream 10Gbps OFM 20 19 2 1 0dBm Block diagram vertical e/o cable Optical Fan-out Module at 9 th storey BEOC

16. WP F/L Development Pressure Balanced Oil-Filled cable Density oil is ~ density sea water  cable floats in sea water Contains 11 fibres, 2 Cu conductors For each DOM a break-out of 1 fibre, 2 Cu conductors 30/03/2011 16 Break-out box with fibre cable tray

17. WP F/L Pressure Balanced Oil Filled cable 30/03/201117 2 nd prototype also tested on overpressure (6 Bar)

18. WP F/L Filling the cable with oil 30/03/201118 Cable traysOil filling installation High pressure resistant ‘T-connectors’ e/o cable

19. WP F/L storey e/o cable 30/03/201119 Break-out in VEOC DOM to VEOC umbilical with splitter box for e.g. hydrophone Splitter box in BEOC contains DC/DC=400/12 V convertor in oil

20. WP F/L Splitter box on storey cable Galvanic separation between DOM and cable  DC/DC=400/12V convertor in cable  DC/DC convertor in oil at 60 MPa Efficiency > 90% for loads between 7 W and 20 W at 60 MPa (8 weeks @ 15 W) Principle: 380V 12V Galvanic barrier fuse

21. WP F/L Summary and conclusion Deployment of 320 detection units within ~4 year is challenging Return of experience from Antares, NEMO and KM3NeT (test) deployments very valuable Compact deployment method is feasible Further validation/qualification deployments planned Pressure Balance Oil-Filled vertical e/o backbone cable being validated Aim: deployment of first KM3NeT DU-prototype planned half 2012 30/03/201121