1. SILICON PIXELS DETECTOR
FORCED CONVECTION COOLING TEST
COOLING PRINCIPLE
Vittore Carassiti, Marco Statera, Ferruccio Petrucci, Luca Landi, Stefano Squerzanti, Stefano Chiozzi, Manuel Bolognesi, Michele Melchiorri, Claudio Padoan
CERN , 11/12/2007

2. Vittore Carassiti - INFN FE
SUMMARY
DESIGN CONCEPT
DESIGN DEVELOPMENT
TEST SETUP
PEOPLE INVOLVED
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE
CERN , 11/12/2007

3. Vittore Carassiti - INFN FE
DESIGN CONCEPT
THE DESIGN OF THE DETECTOR REQUIRES TO MINIMIZE THE MATERIAL BUDGET
THE COOLING SYSTEM CONCEPT DESIGN FOLLOWS THE SAME REQUIREMENT
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE
CERN , 11/12/2007

4. STARTING DESIGN CONCEPT - 1Nr
ELEMENT
THERMAL
CONDUCTIVITY
(W/mK)
THICKNESS
(mm) 1
K1100 CARBON FIBER
1000
0,1 2
THERMAL COMPOUND
8,7*
0,2 3
PIXELS
205 4
BUMPS
0,4**
0,01 5
SENSORS
COOLING PLATE
HEAT FLUX
CONDUCTIVE COOLING
THIN COOLING PLATE + COOLING CIRCUIT
SURROUNDING THE DETECTOR
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE

5. STARTING DESIGN CONCEPT -2
Cooling system
BOUNDARY CONDITIONS
SURFACE COLLECTING THE POWER
SCP = 27 x60 mm^2
HEAT FLUX UNIFORM
HF = 2 W/cm^2 = 2E+04 W/m^2
Supporting plate
Heat flux
TEMPERATURE DISTRIBUTION ON
THE DETECTOR NOT UNIFORM (>30°C)
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE

6. MOVING TOWARD A DIFFERENT COOLING CONCEPT - 1
CONVECTIVE COOLING USING A NITROGEN GAS FLOW
AND THIN FLAT WALLS
CONVECTION COEFFICENT = 55 W/m^2K
MAX DETECTOR TEMP = 2,6 °C
GOOD TEMPERATURE UNIFORMITY
COOLING FLOW
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE

7. MOVING TOWARD A DIFFERENT COOLING CONCEPT - 2
MAX DISPL = 1,3 mm
MAX STRESS = 700 Mpa
WALL THICKNESS = 0,2 mm
PRESSURE INSIDE = 0,1 MPa
THE FLAT WALL NEEDS A THICKNESS > 0,2 mm
TOO MUCH MATERIAL !!
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE

8. Vittore Carassiti - INFN FE
THE DEVELOPED DESIGN – 1
SHARING THE JOBS :
CYLINDRICAL WALLS SUPPORTING THE PRESSURE
FLAT WALLS DEFINING THE FLOW CROSS SECTION
CHOSEN MATERIAL = KAPTON TYPE H
THINNER THICKNESSES REQUIRED :
CYLINDRICAL WALL = 40 MICRONS
FLAT WALL = 10 MICRONS
ROUND WALL
KAPTON RADIATION LENGTH = 28,6 cm
COOLING VESSEL RADIATION LENGTH = 0,035% Xo
FLAT WALL
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE

9. Vittore Carassiti - INFN FE
THE DEVELOPED DESIGN - 2
MAKING THE PARTS
ALL PARTS MADE BY
FERRARA WORKSHOP
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE
CERN , 11/12/2007

10. TESTS @ ROOM TEMPERATURE
THE DEVELOPED DESIGN – 3
ROOM TEMPERATURE
THE FOLLOWING TESTS HAVE BEEN DONE :
KAPTON CREEP
KAPTON FAILURE PRESSURE
QUALITY OF THE JOINT KAPTON-RESIN-ALUMINUM
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE
CERN , 11/12/2007

11. TEST 1 -BONDING ALUMINUM FRAME & KAPTON FOIL
PREPARATION OF THE JOINTS :
ALUMINUM JOINT ABRADED AND DEGREASED
KAPTON JOINT LIGHTLY ABRADED AND DEGREASED
CURING TIME : 16 40°C
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE
CERN , 11/12/2007

12. TEST 2 - BONDING ALUMINUM FRAME & KAPTON FOIL
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE
CERN , 11/12/2007

13. TEST 3 - KAPTON CREEP TEST
Working pressure Wp = 1 bar
Test pressure Tp = 2Wp = 2 bar
AFTER TWO Tp NO EVIDENCE
OF CREEP
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE
CERN , 11/12/2007

14. TEST 4 - KAPTON FAILURE PRESSURE
STRESS ON THE VESSEL
BOUNDARY CONDITIONS
Pi = 0,1 Mpa (inner pressure)
Pe = 0 (outher pressure)
s = 5E-05 m (wall thickness)
Di = 47E-03 m (inner diameter)
FAILURE PRESSURE CALCULATION
EQUIVALENT TENSILE STRESS
(Guest criterion)
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE
CERN , 11/12/2007

15. TEST 5 - JOINT KAPTON-RESIN-ALUMINUM
LENGTH OF THE OVERLAP CALCULATION
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE
CERN , 11/12/2007

16. TEST BENCH & READUT SYSTEM
VACUUM
POWER & TEMPERATURES
FLOW RATE
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE
CERN , 11/12/2007

17. OPTIMIZING THE GAS INJECTION -1
Injection channels :
Share the flow rate & avoid the temperature drop on the inner edge of the detector
lateral channels :
the flow is injected cooled until the exit
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE
CERN , 11/12/2007

18. OPTIMIZING THE GAS INJECTION - 2
SILICON WINDOW
DETECTOR MOCK UP
& DISTRIBUTING CHANNELS
THERMO-CAMERA
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE
CERN , 11/12/2007

19. COMPARING THE THERMOCAMERA RESULTS WITH THE THERMAL MODEL
THERMOCAMERA IMAGE
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE
CERN , 11/12/2007

20. THE TESTED PROTOTYPE REALIZATION
THE PROTOTYPE
ROUND WALLS = 40 microns
FLAT WALLS = 10 microns
CROSS SECTION = 8x46 mm^2
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE
CERN , 11/12/2007

21. TESTING THE WIRES STABILITY UNDER GAS FLOW
(6 groups of 10 wires)
NITROGEN FLOW RATE RANGE : FROM 0 TO 12 m^3/h (1,5 the nominal rate) ; THE WIRES ARE STEADY
NA62 GTK Meeting , CERN
Vittore Carassiti - INFN FE
CERN , 11/12/2007

22. Design, simulation, tests, development & construction
Vittore CARASSITI (mech. service)
Marco STATERA (vacuum & cryo service)
Manuel BOLOGNESI (electr. service)
Stefano CHIOZZI (electr. service)
Angelo COTTA RAMUSINO (electr. service)
Luca LANDI (mech. service)
Roberto MALAGUTI (electr. service)
Michele MELCHIORRI (mech. service)
Claudio PADOAN (electr. service)
Stefano SQUERZANTI (mech. service)
NA62 GTK Meeting , CERN
CERN , 11/12/2007