Vibration Analysis of a Vibration Analysis of a Cryocooler for CDMSCryocooler for CDMS

Lauren CoutantLauren Coutant

SULI, summer 2007SULI, summer 2007

What is CDMS?What is CDMS?

Cryogenic Dark Matter Search (CDMS)Cryogenic Dark Matter Search (CDMS) It is known that dark matter exists It is known that dark matter exists [1][1]

Best theory: it is Weakly Interacting Massive Best theory: it is Weakly Interacting Massive Particles (WIMPs) Particles (WIMPs) [2][2]

CDMS is a direct detection experimentCDMS is a direct detection experimentDetects the energy transferred when a WIMP has Detects the energy transferred when a WIMP has

a collision with a nucleus in the detectora collision with a nucleus in the detectorDetector is kept at 50mK with a Gifford McMahon Detector is kept at 50mK with a Gifford McMahon

cryocooler and dilution refrigeratorcryocooler and dilution refrigerator

Two Types of CryocoolersTwo Types of Cryocoolers Gifford-McMahon (GM)Gifford-McMahon (GM)

Uses a piston to push the Uses a piston to push the working fluid through the working fluid through the systemsystem

Piston is located in the Piston is located in the cryocoolercryocooler

Pulse Tube (PT)Pulse Tube (PT) Uses orifice and reservoir Uses orifice and reservoir

instead of pistoninstead of piston Has no moving mechanical Has no moving mechanical

parts inside the cryocooler parts inside the cryocooler [3][3]

[4]

Stirling (GM) versus PT CycleStirling (GM) versus PT Cycle

[5]

Stirling Pulse Tube

Potential Problems from CryocoolerPotential Problems from Cryocooler

All Cryocoolers have some vibrationAll Cryocoolers have some vibration

Vibration can causeVibration can causeHeatHeatElectrical noise, ~TElectrical noise, ~T55

““Vibration free”Vibration free”Vibration on the order of background seismic Vibration on the order of background seismic

motion motion [6][6]

What Causes the Vibrations?What Causes the Vibrations?

GMGMPiston causes motion in the systemPiston causes motion in the system

PTPTFluid traveling through impedances—think of Fluid traveling through impedances—think of

musical instrumentsmusical instrumentsBothBoth

Pressure changes of the working fluid cause Pressure changes of the working fluid cause pipes to deform—think of blood vesselspipes to deform—think of blood vessels

[7]

Which one is better?Which one is better?

[8] p. 314

What type was tested here?What type was tested here?

Cryomech Pulse Cryomech Pulse Tube 415Tube 415

Two StageTwo Stage 11stst Stage of the Stage of the

Cryocooler--room Cryocooler--room temperature to 77Ktemperature to 77K

22ndnd Stage--77K to 4K Stage--77K to 4K

[9]

Vibration

Analysis

AccelerometerAccelerometer

Piezoelectric material experiences charge Piezoelectric material experiences charge separation when a force is appliedseparation when a force is applied

Voltage can be measured and related to the Voltage can be measured and related to the magnitude of the forcemagnitude of the force

Force can be used to find acceleration, F=maForce can be used to find acceleration, F=ma

Adapted from [10]

Vibration Testing: Accelerometer Vibration Testing: Accelerometer LocationLocation

Vibration Testing: Block DiagramVibration Testing: Block Diagram

Vibration Analysis: Lab 3 Set upVibration Analysis: Lab 3 Set up

ResultsResultsFull Spectrum Acceleration Trace

0

5

10

15

20

25

0 20000 40000 60000 80000 100000

Frequency (Hz)

Acc

eler

atio

n (

m/s

^2)

0 to 48.8 Hz Acceleration Spectrum

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0 5 10 15 20 25 30 35 40 45 50

Frequency (Hz)

Acc

eler

atio

n (

m/s

^2)

As a reference, g=9.8 m/s^2

ComparisonComparison

How does this relate to what Tomaru’s How does this relate to what Tomaru’s group got?group got?

How does this relate to the performance of How does this relate to the performance of the current CDMS cryocooler?the current CDMS cryocooler?

Vibration Reduction MethodsVibration Reduction Methods

DistanceDistanceCold head placed away from cryocooler Cold head placed away from cryocooler [3][3]

Was implemented in Lab 3Was implemented in Lab 3Flexible material to absorb vibrationsFlexible material to absorb vibrationsRigid material to resist elastic deformationRigid material to resist elastic deformationActive vibration cancellationActive vibration cancellation

Vibration Reduction Methods: Vibration Reduction Methods: Materials and Counter-weightMaterials and Counter-weight

Adapted from [11] p. 118

Vibration Reduction Methods: Vibration Reduction Methods: Distance and MaterialsDistance and Materials

[8] p. 310

Vibration Reduction Methods: Vibration Reduction Methods: Flexible and Rigid MaterialsFlexible and Rigid Materials

[12]

Vibration Reduction Methods: Vibration Reduction Methods: Flexible ConnectorsFlexible Connectors

Currently in use at Soudan CDMS site.

Vibration Reduction Methods: Vibration Reduction Methods: Flexible Connectors Flexible Connectors

Vibration Reduction Methods: Vibration Reduction Methods: Active CancellationActive Cancellation

[13]

Vibration Reduction Methods: Vibration Reduction Methods: Active CancellationActive Cancellation

Single Pipe Four Pipes Six Pipes

[7]

ConclusionsConclusions Vibration of PT415 should be less than current Vibration of PT415 should be less than current

GM cryocooler at SoudanGM cryocooler at Soudan

More analysis needs to be doneMore analysis needs to be done

Any of the suggested methods of reduction Any of the suggested methods of reduction could be applied.could be applied. Adding flexible materials--least work, but also least Adding flexible materials--least work, but also least

reductionreduction Active cancellation--work intensive, but great Active cancellation--work intensive, but great

reduction, may not dampen vibrations at high reduction, may not dampen vibrations at high frequencyfrequency

Works CitedWorks Cited1.1. Reisetter, Angela. “Reisetter, Angela. “Results from the Two-Tower Run of the Cryogenic Dark Matter Search.”

University of Minnesota. 2005.2. “SuperCDMS Development Project.” SuperCDMS Collaboration. Proposal to DOE and NSF.

2004.3.3. Radebaugh, Ray. “Development of the Pulse Tube Refrigerator as an Efficient and Reliable Radebaugh, Ray. “Development of the Pulse Tube Refrigerator as an Efficient and Reliable

Cryocooler.” Institute of Refrigeration, London. 2000. Cryocooler.” Institute of Refrigeration, London. 2000. <http://cryogenics.nist.gov/Papers/Institute_of_Refrig.pdf>.<http://cryogenics.nist.gov/Papers/Institute_of_Refrig.pdf>.

4.4. Courtney, Bill. “Cryocoolers-Refrigerators producing very low temperatures” Accessed on 6-15-Courtney, Bill. “Cryocoolers-Refrigerators producing very low temperatures” Accessed on 6-15-2007. <http://www.cheshire-innovation.com/news/cryocooler/htm> Cheshire Innovation.2007. <http://www.cheshire-innovation.com/news/cryocooler/htm> Cheshire Innovation.

5.5. Yuan, Sidney. “Pulse Tube Coolers (Cycle, Engines, Cryogenics Refrigerators, Cryocoolers).” Yuan, Sidney. “Pulse Tube Coolers (Cycle, Engines, Cryogenics Refrigerators, Cryocoolers).” <http://www.yutopian.com/Yuan/PT.html> 2000.<http://www.yutopian.com/Yuan/PT.html> 2000.

6.6. Uchiyama, T., K. Kuroda, M. Ohashi, et al. Uchiyama, T., K. Kuroda, M. Ohashi, et al. “Present status of large-scale cryogenic gravitational “Present status of large-scale cryogenic gravitational wave telescope." wave telescope." Classic Quantum GravityClassic Quantum Gravity V 21. 13 Feb. 2004: p. 1161-1172. V 21. 13 Feb. 2004: p. 1161-1172.“Cryomech “Cryomech PT415.” Cryomech, Inc. 2007. <http://www.cryomech.com/DEVELOPMENTS/PT415.htm>PT415.” Cryomech, Inc. 2007. <http://www.cryomech.com/DEVELOPMENTS/PT415.htm>

7.7. Suzuki, T., T. Tomaru, T. Haruyama, et al. Suzuki, T., T. Tomaru, T. Haruyama, et al. "Ultra-Low Vibration Pulse Tube Cryocooler with a "Ultra-Low Vibration Pulse Tube Cryocooler with a New Vibration Cancellation Method ." New Vibration Cancellation Method ." Advances in Cryogenic Engineering: Transactions of the Advances in Cryogenic Engineering: Transactions of the Cryogenic Engineering ConferenceCryogenic Engineering Conference. V. 51. 2006 American Institute of Physics.. V. 51. 2006 American Institute of Physics.

8.8. Tomaru, Takayuki; Toshikazu Suzuki; Tomiyoshi Haruyama; et al. "Vibration analysis of Tomaru, Takayuki; Toshikazu Suzuki; Tomiyoshi Haruyama; et al. "Vibration analysis of cryocoolers." cryocoolers." CryogenicsCryogenics. V44, 2004. p. 309-317.. V44, 2004. p. 309-317.

9.9. ““Cryorefrigerators: Pulse Tube.” Cryomech Inc. 2007. <http://www.cryomech.com/PULSECryorefrigerators: Pulse Tube.” Cryomech Inc. 2007. <http://www.cryomech.com/PULSE%20TUBES.htm>%20TUBES.htm>

10.10. ““Function of Piezoelectric Accelerometers.” PCB Piezotronics. PCB Group, Inc. 2007. Function of Piezoelectric Accelerometers.” PCB Piezotronics. PCB Group, Inc. 2007. <http://www.pcb.com/ techsupport/tech_accel.php>.<http://www.pcb.com/ techsupport/tech_accel.php>.

11.11. Veprik, A.M., S.V. Riabzev, G.S. Vilenchik, et al. “UItra-Iow vibration split Stirling linear cryogenic Veprik, A.M., S.V. Riabzev, G.S. Vilenchik, et al. “UItra-Iow vibration split Stirling linear cryogenic cooler with a dynamically counterbalanced pneumatically driven expander.” cooler with a dynamically counterbalanced pneumatically driven expander.” CryogenicsCryogenics. V4, . V4, 2005. p 117-122.2005. p 117-122.

12.12. Tomaru, Takayuki; Toshikaza Suzuki; Tomiyoshi Haruyama; et al. “Development of a Vibration-Tomaru, Takayuki; Toshikaza Suzuki; Tomiyoshi Haruyama; et al. “Development of a Vibration-Reduction System of Cryocooler for a Cryogenic Interferometric Gravitational Wave Detector.”Reduction System of Cryocooler for a Cryogenic Interferometric Gravitational Wave Detector.”

13.13. Suzuki, T., T. Tomaru, T. Haruyama, et al. "Pulse Tube Cryocooler with Self-Cancellation of Cold Suzuki, T., T. Tomaru, T. Haruyama, et al. "Pulse Tube Cryocooler with Self-Cancellation of Cold Stage Vibration." Cryo Prague 2006. <http://arxiv.org/abs/physics/0611031>.Stage Vibration." Cryo Prague 2006. <http://arxiv.org/abs/physics/0611031>.