2/26/20111Cryogenics SymposiumDay 1 – Thursday March 31, 20111. Ev aporative Cooling‐ Sahar Mirshamsi2. Peltier Effect Bobby Bond3. Dewar’s Flask and Cryogenic Storage Roberto Gomez‐Perez4. Cooling Computers Brady Nash5. Vortex Tube Cooling Joseph Smales6. Pulse Tube Refrigeration‐ Scott Petersen7. Food Processing and Storage Gabriel DilanjiEvaporate CoolingSahar Mirshamsi• Science of Evaporate cooling, basic ideas: Evaporative cooling is based on a physicalphenomenon in which evaporation of a liquid (usually water) into surrounding air coolsan object or a liquid in contact with it.• Evaporative Coolers: Also known as swamp coolers, sump coolers or desert coolers aremost commonly found in homes and small businesses located in dry hot climates.•“Badgir”, a traditional windcatcher in Iran: The dry and warm wind will pass over apond with a fountain gets cool and wet through evaporation.•Cooling Towers(If it does not make the talk longer than 8 minutes)Thermoelectric Cooling OutlineBobby BondPeltier Effect•Materials used to make Thermoelectric coolers•Figure of Merit•Improving Figure of Merit•Disadvantages•Advantage•Applications of Thermoelectric Cooling•Common DevicesSources (not all): •http://www.electronics‐cooling.com/2006/11/effect‐of‐improved‐thermoelectric‐zts‐on‐electronic‐module‐coolability/•http://www.tec‐microsystems.com/EN/Intro_Thermoelectric_Coolers.htmlDewar’s Flask and Cryogenics Storage OutlineINTRODUCTIONSir. James Dewar Modern applicationsGravity Probe bThermosDewar’s FlaskOriginal MaterialsPicturesDevelopmentSeal FillOut gassingGetters UseModern designsPicturesOther Storage DevicesDifferent types Liquid cylindersTanksWhen these devices where createdDifferences in use compared to Dewar’s flaskConclusionComputer CoolingBrady Nash• Heat Buildup and Hardware Damage• Types of System Cooling & Implementation– Air Cooling– Liquid Submersion• Types of Spot Cooling & Implementation– Passive/Active heat‐sinks– Water cooling– Heat Pipes– Phase‐change cooling– Liquid nitrogen cooling• Overclocking & Cooling CautionsVortex Tube Cooling Outline• Brief History– Invented: 1933 Georges J. Ranque– Design improved & Large publication: 1947 Rudolf Hilsch• Theory as to how it works:– Compressed airvortex motionhot out /reverse flowcool out, opposite hot – Pressure differences and conservation of angular momentum– C.L. Stong– J. J. Van Deemter,• Basic design considerations• Efficiency – Data tables from various manufacturers• Applications– Poor efficiency: good for “spot” cooling– Cooling electrical cabinets• Possible demo• Clicker QuestionJoseph Smales2/26/20112Slide 1: IntroductionBasic overview of pulse tube refrigerationHow it uses acoustics and involves no cold moving partsSlide 2: Beginning ResearchNASA origins for space applications: lower mass and longer lifeOriginally abandoned due to discouraging resultsPhase shift discovery opened topic back upSlide 3: Picture DescriptionUsing a picture of a pulse tube refrigerator, I’ll go over the components of the diagramHow it is a Stirling‐typeSlide 4: Individual ComponentsCompressed gas traveling through systemExplain regenerator and heat exchangersSlide 5: Comparison to other re frigeratorsNo need for displacerEfficient (very little interferences)Can only reach temperatures around 1 KSlide 6: Current UsesVery popular in space applications (telescopes)Ben and Jerry’s interest in thermoacousticsSemiconductor fabricationSlide 7: Future possibilitiesMost effective at very low temperatures (not good for room temperature applications)Combining dilution refrigerators and pulse tubes can achieve milli and micro K temperatures withoutprohibitive costInfrared detection, telecommunication filterspulse tube refrigerationFood Processing and StorageGabriel Dilanji• To be continuedCryogenics SymposiumDay 2– Tuesday April 5, 20111. Superfluidity Kristin Zych2. SuperSolid Icon Mazzaccar3. Vortex State‐type II superconductors Joshua Arlund4. Superconducting Magnets Lana Muniz5. Nuclear Demagnetization Cooling Roman Ciapurin6. CDF Cryo System Matt Snowball7. Quantum Computing Adam ButlerSuperfluidity OutlineDiscovery‐when, by whomProperties‐lambda point, viscosity Theory‐Bose/Fermi statisticsApplications‐superconductors Recent developments‐supersolidsSupersolids• What is a supersolid and what are its characteristics?• Motivation for the existence of a supersolid.– “Speculations on Bose‐Einstein Condensation and Quantum Crystals” by G.V. Chester, Phys Rev. A (1970)• How is it possible to measure supersolidity?– Tors ion al Oscillator – What would signal its existence within the data?• Kim and Chan’s experimental data confirming the existence – “Probable observation of a supersolid helium phase” by Kim and Chan, Nature (2004)• Controversy over experimental data– Certain processes eliminate the characteristics that signaled supersolidity– Experimental data that support its nonexistence• Alternate explanation for what is occurring at low temperatures• Chan and Kim’s reaction to experimental data against their case• Future for Supersolids?– Possibilities in optical lattices– “Dynamical Creation of a Supersolid in Asymmetric Mixtures of Bosons”, Phys Rev. Letters (2009)– Maybe it does not exist at all.Vortex State in type 11 superconductorsWhat is a superconductorType I and type II differencestransition (sharp or gradual)penetrating magnetic fieldWhat is the vortex statepenetrating flux linesvortex supercurrentsCore sizehow many are presentdistributionUses of vortex states2/26/20113Superconducting Magnets – OutlineIntroduction – What is a superconducting magnet?History – Heike Kamerlingh Onnes, GeorgeYntema, andtype-II superconductorsMaterials and Operation – How a superconducting magnetworks. Persistent mode.Advantages/Disadvantages – Comparison to regular magnets.Applications - MRI/NMR- Paricle AcceleratorsNuclear Demagnetization• History, what is it, temperature ranges• Magnetism in materials• Principles: entropy cycle (main focus)• Nuclear vs paramagnetic salts• Laboratory setup (main focus)• Limitations, external fields, H/T • Multiple stages, improved technologiesCDF Cryo System Outline•What is CDF•Where is it? What does it do?•Why does it need to be cold?•How cold does it get?•Cryo Systems•What are the