Petar Kesic TRAC Summer 2017 Cooling of CMS Detectors CMS C - - PowerPoint PPT Presentation

Petar Kesic
 TRAC

Summer 2017

Cooling of CMS Detectors

CMS

• Compact Muon Solenoid
• A general purpose detector at the Large Hadron

Collider (LHC) at CERN.

• One of 4 detection points around the LHC.
• Acts like a camera (which detects photons) taking

3D “photographs” of particle collisions and recreating images of the collisions.

Inner / Silicon / Pixel Trackers High Granularity Calorimeters

• Detectors heat up because of energy released during detection and the operation of the

electronic components.

• In order to improve operation and prevent damage, it is necessary to transfer heat away

from the components.

• For performance and environmental reasons, CO2 has been chosen as the primary

coolant.

• The detector components are mounted on planks with CO2 cooling tubes embedded

and then placed into the CMS.

• It is necessary to keep the density and thickness of the planks low so that particles may

continue to detectors which are farther away.

• This poses certain design challenges.
• Low density and thickness usually means lower strength, so a high strength material is

needed.

• Low density usually means poor heat transfer, so a material with exceptional heat

transfer capability was needed.

• Carbon fiber and carbon foam were chosen as the plank material because of their

superior strength to density ratios and excellent heat transfer capabilities.

Performance of CO2 and Carbon Fiber / Foam Planks

• Why are we testing?
• To assure that components are able to stay within acceptable
• perating temperatures when
• the system is operating under standard conditions.
• the system is operating outside of standard operating conditions.
• What parameters are we looking at?
• Delta T, Delta P

, CO2 Phase Changes, Thermal Runaway, etc.

CO2 Phase Diagram

Different Detectors

• Flat Barrel / PS Modules
• 2S
• HG Calorimeter

Flat Barrel

Power Calculations

2S

HG Calorimeter

• Assisted Maral Alyari
• Goal: Test the two phase CO2 cooling performance of FH cassette tubing with capillary at

various angles around the beam pipe.

• Stainless steel tubes are sandwiched between 4 layers of insulation foam.
• CO2 temperature is monitored by RTDs placed on the tubing.
• Voltage is applied to stainless steel tubing to mimic the heat load on the tubing.
• Tubing acts as a heater.
• The flow is monitored by a flowmeter placed at the inlet.
• Two pressure transmitters are placed at the inlet and the outlet.
• Attempted to cool various heat loads with minimum possible flow and lowest possible ΔP

.

• Data is analyzed by calibrating the RTD measurements to read the same temperature as the

return CO2 at 0 Watts.

HG Calorimeter Testing

270 deg. 0 deg.

Some HG Cal / CO2 Results

00000 00000

Some HG Cal / CO2 Results

• Assisted Kirstyn Carlson
• Goal: Test the water and ethylene glycol cooling performance of 2S Module.
• Coolant is run through aluminum support structure.
• Coolant temperature is monitored by RTDs placed at various locations on the module.
• Voltage is applied to resistive heaters to mimic the heat load.
• Attempted to cool various heat loads with minimum possible flow and lowest possible ΔP

.

• Data is analyzed by calibrating the RTD measurements to read the same temperature as the

return fluid at 0 Watts.

2S Testing

Some 2S Data / Ethylene Glycol Cooling

• Assisted Stefan Gruenendahl
• Goal: Test the CO2 cooling performance of FB Modules.
• CO2 is run through stainless steel tubing sandwiched in carbon fiber foam and sheets.
• CO2 temperature is monitored by RTDs placed on the modules.
• Voltage is applied to resistive heaters to mimic the heat loTubing acts as a heater.
• The flow is monitored by a flowmeter placed at the inlet.
• Attempted to cool various heat loads with minimum possible flow and lowest possible ΔP

.

• Data is analyzed by calibrating the RTD measurements to read the same temperature as the

return CO2 at 0 Watts.

FB / PS Modules Testing

FB / Modules on Plank

Some FB / Co2 Cooling Results

Interactions / Meetings / Workshops / Lectures

• Interactions with Fermilab personnel.
• Interactions with other teachers.
• Workshops
• Lectures
• Tours

Back-To-School

• What can I take back to my students?
• Personal growth.
• “Real world” applications.
• Ideas for lectures and demonstrations.
• Inspiration to integrate particle physics into curriculum.

Acknowledgements

• Special thanks to:
• Stefan Gruenendahl
• Maral Alyari
• Kirstyn Carlson
• Harry Cheung
• and many others