GTK gas cooling system

GTK GAS COOLINGSYSTEM

Marco Statera, Vittore Carassiti, Ferruccio Petrucci, Luca Landi, Stefano Chiozzi, Manuel Bolognesi

NA62 - GTK working group meeting 13-12-2011

OUTLINE

• DESIGN CONCEPT AND OPTIMIZATION• TEST SETUP• RESULTS• SYSTEM• ASSEMBLY PROCEDURE• CONCLUSIONS

Na62 GTK working group meeting, CERN 13-12-2011 Marco Statera 2

OUTLINE



DESIGN REQUIREMENT THE DESIGN OF THE DETECTOR REQUIRES TO MINIMIZE

THE MATERIAL BUDGET THE COOLING SYSTEM CONCEPT DESIGN FOLLOWS THE

SAME REQUIREMENT


Cooling system

Supporting plate

Heat flux

HEAT FLUX UNIFORM: HF = 2 W/cm2

TEMPERATURE GRADIENT > 30° C

CYLIDRICAL WALL 40 m

FLAT WALL10 m

SHARING THE JOBS :•CYLINDRICAL WALLS SUPPORTING THE PRESSURE•FLAT WALLS DEFINING THE FLOW CROSS SECTION

MATERIAL BUDGET X0 = 0.035 %

MAKING THE PARTS


ALL PARTS MADE BY FERRARA WORKSHOP

MECHANICAL TESTS

KAPTON CREEP– working pressure Wp = 1 bar– Test pressure Tp = 2Wp = 2 bar– AFTER TWO WEEKS @ Tp

NO EVIDENCE OF CREEP• KAPTON FAILURE PRESSURE

– safety factor (40 m) 2.0 @ Wp• QUALITY OF THE JOINT

KAPTON-RESIN-ALUMINUM– safety factor 1.9


OPTIMIZATION


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

OUTLINE



ROOM TEMPERATURE MEASUREMENT


THERMO-CAMERA

SILICON WINDOW

DETECTOR MOCK UP & DISTRIBUTING CHANNELS

THERMAL MODEL VALIDATION


THERMOCAMERA IMAGE

THERMAL MODEL

TEST BENCH AND READOUT


FLOW RATEPOWER & TEMPERATURES

VACUUM

VACU

UM

TEMPERATURES VS TIME

FLOW

TEMPERATURE SENSORS


FLOWFLOW

T0

T10

T4 T3 T2 T1

T9

T5T6 T7 T8

T11T12T13T14

OUTLINE



RESULTS - 1


T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 WFlow l/min

11,7 15,3 0,7 1,0 13,8 18,5 18,5 26,0 34,0 15,5 0,4 1,8 1,0 0,3 -1,2 24 113

15,0 20,0 0,3 1,2 18,5 23,2 23,4 32,6 44,0 19,3 -0,7 0,0 -1,6 -3,2 -4,4 32 123

32,7 33,5 2,6 4,6 27,5 34,4 36,2 48,6 67,8 33,2 2,8 1,9 -0,6 -1,8 -1,9 48 138

21,3 23,4 -6,4 -4,9 17,4 23,2 24,8 37,0 56,3 22,0 -6,4 -8,0 -11,3 -12,7 -12,6 48 140

6,0 2,0 -25,0 -24,3 -4,1 0,8 3,3 15,3 34,5 3,0 -26,0 -27,5 -30,8 -31,7 -31,2 48 142

43,0 44,3 8,5 9,9 35,4 42,3 45,8 60,0 82,5 43,6 8,3 5,9 2,4 0,4 0,4 56 142,5

• 32 W – 48 W – 56 W results Pdigital/Psensor = 3.7• 48 W: different sensor temperatures regulating the flow (4 l/min)

RESULTS- 2


measured temperatures of the sensor area (T10-T14)

ΔT < 6° C average temperature regulated by flow (+5° C ÷ -30° C )

RESULTS - 3


measured temperatures of digital area (T0-T4 and T5-T9) and sensor area (T10-T14)

• set sensor and digital temperature @ nominal power <-> flow regulation• reduce max temperature and gradient

TYPICAL MEASUREMENT - 1


sensor temperature regulation by flow at different powers

TYPICAL MEASUREMENT - 2


4 W -> 56 W Pdig/Psens=3.7 32 W Pdig/Psens=3.7the system is optimized for the asymmetric power distribution

T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 W l/min-30 -29,5 -45,4 -45,6 -36,4 -31,5 -30 -25,3 -16,7 -31,8 6,3 1,8 -2 -4 -4,5 32 136

HEATERS & MATERIAL

19

before after

0 56.0 55

1 55.5 55

2 63.0 61

3 66.3 65

4 50.5 50

5 57.0 56

6 58.6 57

7 48.7 47

8 46.8 45

9 50.8 50

digital resistance measured values [Ω]before and after the test of mockup #11avg = 55.3 Ωstd = 6.3 Ω

Na62 GTK working group meeting, CERN 13-12-2011 Marco Statera

effect on temperature distribution• local power distribution• material thermal properties

EXTRAPOLATION


resistor spread increases longitudinal and trasversal gradient

given a flow and power Ti = T x Ri / 60Ri measured; 60 Ω nominal R; correction (extrapolation) up to 20° C

OUTLINE



THE SYSTEM

• COOLING: – GAS FROM LIQUID

• THE SYSTEM– how it works and costs

• RUN AND MAINTENANCE• PROCEDURES

– pumpdown, cooldown, time constants : fast ramp up/down, emergency warm up, 1 heater broken

• INTERLOCK


GAS FROM LIQUID


Pro• liquid is a reserve of gas• fast restart time after an

emergency stop• cooling power: 170 W @ 77K• safe shut off: the emergency valve

reduces the dewar pressure

Cons• needs cryogenic liquid• pumping vapor

COST

4 systems: 370 k€

• the gas above a liquid bath is forced into the cooling pipes and cooled down by a cold head• the pressure of the dewar is kept constant; a heater at the cold head also prevents low pressures• the flow is regulated by the valve• additional relief valve

THE SYSTEM• gas from liquid solution is proposed• three stations: one coling station is not cheaper

since the cost of the cryogenic lines. Three pumping/cooling systems are required

• each station is independent (no crosstalks)• Installation side: Jura or Saleve• 20 m of cryogenic lines:

– the cooling station few meters far from the beampipe– the outer diameter is about 35 mm, we asked for a

100x100 mm2 cross section in the trench• the control system (PLC) is outside the cavern


RUN AND MAINTENANCERUN• refill liquid nitrogen• start the coldhead• emergency stop -> some nitrogen gas lost; the liquid is a

reserve. NO access required• 6 months runningSAFETY• cryostat: pressurized vessel• cold nitrogenstandard issues to be discussed with lab safety staffMAINTENANCE every 9000 hrs (12 months run)• coldhead maintenance (2 skilled persons for 2 days): head

o-ring kit and compressor filters• valves check (emergency test)


PROCEDURES

• pumpdown• cooldown• turning on and regulation• warmup• one chip failure• emergency


PUMPDOWN


turbopump nominal pumping speed: 70 l/s (N2)typical working pressure < 1 E-5 mbarImprove vacuum performance: faster pumpdown and lower ultimate pressure• accurate handling/cleaning• UHV materials• vacuum before installing

COOLDOWN


stable cooldown conditionsset temperature and cooling speed by flow regulationi.e. regualting the valve

29-11-2011 COOLDOWN TEMPERATURES AND FLOW

TURN ON AND REGULATION


+ 8 W (16 –> 24 W)ΔT 25 °C in 35 sthe full digital power on (48 W) requires control (heater)

regulating the flow10 seconds compatible with a few seconds full on/off valve

TURN ON PROCEDURE• a heater resistor is required (on the N2 line)

• use of an additional temperature sensor(a TC not on the sensor)

• increase the flow regulating the board temperature by the heater -> nominal flow (sensor temperature > -20 Celsius)

• turn on the sensors and turn off the heater• regulate the SENSOR temperature by the valve

(flow)


WARM UPAND CHIP FAILURE


• self warm up – cooling turned off• max warming speed about 40 K/h• external heating not required

• temperature drop in case the heater (chip) fails is about 10 Degrees @ power 32 W • the system reads one temperature, may change the flow and/or set an allarm

EMERGENCY


• about 25 seconds with the valve closed: temperature rise 4 K/s • @25 seconds power is stopped • no need of very fast interlock: about 1 second

May 2011

INTERLOCK• INPUT (4)

– sensor temperature (average or 1 point)– TC on the board (requested)– chip power supply current– emergency signal

• CONTROL– regulating valve opening (flow)– gas heater– bypass valve (cryostat)– coldhead + coldhead heater

• OUTPUT (3)– sensor temperature (crosscheck)– regulating valve opening– status (OK/alarm)

• PLC (fully hardware – interlock & control)– outside the cavern– no interaction during run– RATE: about 1Hz (typical 10Hz)


PROGRAMS• COOLDOWN

– stable flow (i.e. valve opening)– regulating temperature by TC on the board

• STANDBY – preparation before run and after run– TC on the board useful

• RUN– control loop: Si temperature <-> valve opening

• WARM UP• EMERGENCY

– close the regulating valve (normally closed)– open the safety valve of the dewar (1 atm in seconds)– turn off the cryohead (and heating to room temperature if

possible)– emergency signal output


OUTLINE



INTEGRATION – PHASE 1

TEFLON MASK ALIGNER

SLIDING SUPPORT GUIDES

FIXED SUPPORT

mask aligner : the supports are inserted in the reference places

UNDERCUT FITTING THE PCB THICKNESS

36Na62 GTK working group meeting, CERN 13-12-2011 Marco Statera

TEFLON MASK ALIGNER

PCB SUPPORTING PLATE

REFERENCE PINS

Mounting the mask aligner in the PCB supporting plate

TEFLON MASK ALIGNER SEAT

SLIDING SUPPORT GUIDES & FIXED SUPPORT



REFERENCE PINSMASK ALIGNER

Glueing the sliding support guides and the fixed support on the PCB

PCB SUPPORTING PLATE



SLIDING SUPPORTS

PCB

inserting the sliding support after the resin curing



PCB SUPPORT PLATE

PCB

mounting PCB & detector supports on The PCB support plate

DETECTORSUPPORTS



gluing the detector on the detector supports

PCB SUPPORT PLATE

PCB

DETECTOR REFENCE UNDERCUT

REFERENCE PINSDETECTORSUPPORTS

DETECTOR





INNER REFERENCE CENTRE OF THE DETECTOR

OUTHER REFERENCE CENTRE OF THE DETECTOR

The centre of the detector is referred outside the vacuum vessel

DETECTOR CENTRE (NOMINAL)

bonding the wires

WIRE BONDS



ASSEMBLING THE TWO HALF VESSELS



MOUNTING THE TUBES



THERMAL SHOCK ROOM TEMPERATURE TO 77

K


TEST OF THE PCB & DETECTOR ASSEMBLY PROCEDURE

TEAM


Ferruccio PETRUCCIVittore 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)

design, simulation, tests, development & construction

CONCLUSIONS -1• design concept and optimization

– mechanical design and test: safety factor >2– material budget Xo = 0.035 %

• optimization– room temperature and working condition test benches – FEM flow simulation validated

• the results we have shown– the final prototype tested in working conditions: power, power

distribution, temperature and vacuum– the system has been tested up to 56 W (actual power distribution)– regulation of the sensor temperature by the flow rate:

0 ÷ -20° C @ 48 W – the system can work with different power distributions: 32 W

homogeneus power distribution resultsNa62 GTK working group meeting, CERN 13-12-2011 Marco Statera 48

CONCLUSIONS - 2• system overview

– cooling method: gas from liquid nitrogen– installation requirements– no access required during a full run– measured parameters for different working states

• control and interlock– input/output defined– running programs defined– interlock conceptual design for different working states

• integration– realistic integration sequence– three points holder assembled and tested in severe thermal conditions


GTK gas cooling system

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