DOCSLIB.ORG

Tech Tuesday

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Tech Tuesday EExplainingxplaining CCryogenicsryogenics Cryogenics Cryogenics is the science of producing and studying low-temperature conditions. Th e word cryogenics comes from the Greek word cryos, meaning “cold,” combined with a shortened form of the English verb “to generate.” It has come to mean the generation of temperatures well below those of normal human experience. More specifi cally, a low-temperature environment is termed a cryogenic environment when the temperature range is below the point at which permanent gases begin to liquefy. Permanent gases are elements that normally exist in the gaseous state and were once believed impossible to liquefy. Among others, they include oxygen, nitrogen, hydrogen, and helium. Th e origin of cryogenics as a scientifi c discipline coincided with the discovery by nineteenth-century scientists that the permanent gases can be liquefi ed at exceedingly low temperatures. Consequently, the term “cryogenic” applies to temperatures from approximately −100°C (−148°F) down to absolute zero (the coldest point a material could reach). Th e temperature of any material—solid, liquid, or gas—is a measure of the energy it contains. Th at energy is due to various forms of motion among the atoms or molecules of which the material is made. A gas that consists of very rapidly moving molecules, for example, has a higher temperature than one with molecules that are moving more slowly. In 1848, English physicist William Th omson (later known as Lord Kelvin; 1824–1907) pointed out the possibility of having a material in which particles had ceased all forms of motion. Th e absence of all forms of motion would result in a complete absence of heat and temperature. Th omson defi ned that condition as absolute zero. Words to Know Absolute zero = Th e lowest temperature possible at which all molecular motion ceases. It is equal to −273°C (−459°F). Cryogenics = the science which involves very low temperatures, usually regarded as below -150F (-100C). Liquid Nitrogen, Oxygen, Argon, Helium and Hydrogen are all cryogenic. Cryo-Treating = the treatment of metals and other materials at very low (-300F) temperatures, resulting in certain property changes Cryonics = Th e practice of freezing humans who are not curable by current medical technology, in the hope that ways may be found to bring them back to life at some future time when ways of repairing the damage caused by the freezing process have been developed, as well as cures for the diseases or other causes of death which necessitated their cryonics suspension. Dew Point = the temperature at which liquid fi rst condenses when a vapor is cooled Kelvin temperature scale = A temperature scale based on absolute zero with a unit, called the kelvin, having the same size as a Celsius degree. Liquefi ed Gases = the liquid form of a gas which under normal (atmospheric pressure and ambient temperature) conditions of pressure and temperature are found only as a gas. Liquid Nitrogen and Liquid Oxygen are good examples. LNG = liquefi ed natural gas, a fuel. Liquefi ed by cooling below the normal boiling point, approximately -260F (-160C) Nitrogen = a naturally occurring atmospheric gas, 78% of air by volume, inert, boiling point is -320F (-196C) Normal Boiling Point = the temperature at which a liquid boils when under a total pressure of one atmosphere Superconductivity = Th e ability of a material to conduct electricity without resistance. An electrical current in a superconductive ring will fl ow indefi nitely if a low temperature (about −260°C) is maintained. Th omson’s discovery became the basis of a temperature scale based on absolute zero as the lowest possible point. VALVESV ALV ES CYLINDERS CRYOGENIC HOSES & PAIN TS ACCESSORIES Evergreen Midwest Co 8976 Osborne Drive Mentor, OH 44060 www.Ever GreenMidwest.c om Toll: 800.659.3358 Phone: 440.255.5540 Fax: 440.255.6434 Email: [email protected] EExplainingxplaining CCryogenicsryogenics Th at scale has units the same size as the Celsius temperature scale but called kelvin units (abbreviation K). Absolute zero is represented as 0 K, where the term degree is omitted and is read as zero kelvin. Th e Celsius equivalent of 0 K is −273°C, and the Fahrenheit equivalent is −459°F. One can convert between Celsius and Kelvin scales by one of the following equations: °C = K − 273 or K = °C + 273 Cryogenics, then, deals with producing and maintaining environments at temperatures below about 173 K. One aspect of cryogenics involves the development of methods for producing and maintaining very low temperatures. Another aspect includes the study of the properties of materials at cryogenic temperatures. Th e mechanical and electrical properties of many materials change very dramatically when cooled to 100 K or lower. For example, rubber, most plastics, and some metals become exceedingly brittle. Also many metals and ceramics lose all resistance to the fl ow of electricity, a phenomenon called superconductivity. In addition, helium that is cooled to very nearly absolute zero (2.2 K) changes to a state known as superfl uidity. In this state, helium can fl ow through exceedingly narrow passages with no friction. Methods of producing cryogenic temperatures Cryogenic conditions are produced by one of four basic techniques: heat conduction, evaporative cooling, cooling by rapid expansion (the Joule-Th omson eff ect), and adiabatic demagnetization. Th e fi rst two are well known in terms of everyday experience. Th e third is less well known but is commonly used in ordinary refrigeration and air conditioning units, as well as in cryogenic applications. Th e fourth process is used primarily in cryogenic applications and provides a means of approaching absolute zero. Heat conduction is a relatively simple concept to understand. When two bodies are in contact, heat fl ows from the body with the higher temperature to the body with a lower temperature. Conduction can occur between any and all forms of matter, whether gas, liquid, or solid. It is essential in the production of cryogenic temperatures and environments. For example, samples may be cooled to cryogenic temperatures by immersing them directly in a cryogenic liquid or by placing them in an atmosphere cooled by cryogenic refrigeration. In either case, the sample cools by conduction (or transfer) of heat to its colder surroundings. Th e second process for producing cryogenic conditions is evaporative cooling. Humans are familiar with this process because it is a mechanism by which our bodies lose heat. Atoms and molecules in the gaseous state are moving faster than atoms and molecules in the liquid state. Add heat energy to the particles in a liquid and they will become gaseous. Liquid perspiration on human skin behaves in this way. Perspiration absorbs body heat, becomes a gas, and evaporates from the skin. As a result of that heat loss, the body cools down. Cryogens and Th eir Boiling Points EExplainingxplaining CCryogenicsryogenics In cryogenics, a container of liquid is allowed to evaporate. Heat from within the liquid is used to convert particles at the surface of the liquid to gas. Th e gas is then pumped away. More heat from the liquid converts another surface layer of particles to the gaseous state, which is also pumped away. Th e longer this process continues, the more heat is removed from the liquid and the lower its temperature drops. Once some given temperature is reached, pumping continues at a reduced level in order to maintain the lower temperature. Th is method can be used to reduced the temperature of any liquid. For example, it can be used to reduce the temperature of liquid nitrogen to its freezing point or to lower the temperature of liquid helium to approximately 1 K. A third process makes use of the Joule-Th omson eff ect, which was discovered by English physicist James Prescott Joule (1818–1889) and William Th omson, Lord Kelvin, in 1852. Th e Joule-Th omson eff ect depends on the relationship of volume (bulk or mass), pressure, and temperature in a gas. Change any one of these three variables, and at least one of the other two (or both) will also change. Joule and Th omson found, for example, that allowing a gas to expand very rapidly causes its temperature to drop dramatically. Reducing the pressure on a gas accomplishes the same eff ect. To cool a gas using the Joule-Th omson eff ect, the gas is fi rst pumped into a container under high pressure. Th e container is fi tted with a valve with a very small opening. When the valve is opened, the gas escapes from the container and expands quickly. At the same time, its temperature drops. Th e fi rst great success for the Joule-Th omson eff ect in cryogenics was achieved by Kamerlingh Onnes in 1908 when he liquefi ed helium. Th e Joule-Th omson eff ect is an important part of our lives today, even though we may not be aware of it. Ordinary household refrigerators and air conditioners operate on this principle. First, a gas is pressurized and cooled to an intermediate temperature by contact with a colder gas or liquid. Th en, the gas is expanded, and its temperature drops still further. Th e heat needed to keep this cycle operating comes from the inside of the refrigerator or the interior of a room, producing the desired cooling eff ect. Th e fourth process for producing cryogenic temperatures uses a phenomenon known as adiabatic demagnetization. Adiabatic demagnetization makes use of special substances known as paramagnetic salts. A paramagnetic salt consists of a very large collection of particles that act like tiny (atom-sized) magnets. Normally these magnetic particles are spread out in all possible directions.
Load more

Recommended publications
  • 9 Xenon Handling and Cryogenics
    9 Xenon Handling and Cryogenics 9.1 Overview The Xe handling and cryogenics strategy of LZ derives strongly from the successful LUX program and takes maximum advantage of key technologies demonstrated there: chromatographic krypton removal, high-flow online purification, high-efficiency two-phase heat exchange, sensitive in situ monitoring of Xe purity, and thermosyphon cryogenics. In many cases, the primary technical challenge of the LZ implementation is how to best scale up from LUX. Two classes of impurities are of concern: electronegatives such as O2 and H2O that suppress charge and light transport in the TPC, and radioactive noble gases such as 85Kr, 39Ar, and 222Rn that create backgrounds that are not amenable to self-shielding. Both types of impurities may be found in the vendor- supplied Xe, and both may also be introduced into the detector during operations via outgassing and emanation. The purity goals are summarized in Table 9.1.1. We have three mitigation techniques to control these impurities. First, electronegatives are suppressed during operations by continuous circulation of the Xe in gaseous form through a hot (450 oC) zirconium getter. Gettering in the gas phase is made practical by a two-phase heat exchanger. A metal-diaphragm gas pump drives the circulation and the system is capable of purifying the entire Xe stockpile in 2.3 days. Second, the problematic radioactive species, 85Kr and 39Ar, which have relatively long half-lives (10.8 years and 269 years, respectively) and no supporting parents, can be removed from the vendor-supplied Xe prior to the start of operations.
    [Show full text]
  • Cryogenics in Space
    — 37 — Cryogenics in space Nicola RandoI Abstract Cryogenics plays a key role on board space-science missions, with a range of applications, mainly in the domain of astrophysics. Indeed a tremendous progress has been achieved over the last 20 years in cryogenics, with enhanced reliability and simpler operations, thus matching the needs of advanced focal-plane detectors and complex science instrumentation. In this article we provide an overview of recent applications of cryogenics in space, with specific emphasis on science missions. The overview includes an analysis of the impact of cryogenics on the spacecraft system design and of the main technical solutions presently adopted. Critical technology developments and programmatic aspects are also addressed, including specific needs of future science missions and lessons learnt from recent programmes. Introduction H. Kamerlingh-Onnes liquefied 4He for the first time in 1908 and discovered superconductivity in 1911. About 100 years after such achievements (Pobell 1996), cryogenics plays a key role on board space-science missions, providing the environ- ment required to perform highly sensitive measurements by suppressing the thermal background radiation and allowing advantage to be taken of the performance of cryogenic detectors. In the last 20 years several spacecraft have been equipped with cryogenic in- strumentation. Among such missions we should mention IRAS (launched in 1983), ESA’s ISO (launched in 1995) (Kessler et al 1996) and, more recently, NASA’s Spitzer (formerly SIRTF, launched in 2006) (Werner 2005) and the Japanese mis- sion Akari (IR astronomy mission launched in 2006) (Shibai 2007). New missions involving cryogenics are the ESA missions Planck (dedicated to the mapping of the cosmic background radiation) and Herschel (far infrared and sub-millimetre observatory), carrying instruments operating at temperatures of 0.1 K and 0.3 K, respectively (Crone et al 2006).
    [Show full text]
  • Cryogenics – the Basics Or Pre-Basics Lesson 1 D
    Cryogenics – The Basics or Pre-Basics Lesson 1 D. Kashy Version 3 Lesson 1 - Objectives • Look at common liquids and gases to get a feeling for their properties • Look at Nitrogen and Helium • Discuss Pressure and Temperature Scales • Learn more about different phases of these fluids • Become familiar with some cryogenic fluids properties Liquids – Water (a good reference) H2O density is 1 g/cc 10cm Total weight 1000g or 1kg (2.2lbs) Cube of water – volume 1000cc = 1 liter Liquids – Motor Oil 10cm 15W30 density is 0.9 g/cc Total weight 900g or 0.9 kg (2lbs) Cube of motor oil – volume 1000cc = 1 liter Density can and usually does change with temperature 15W30 Oil Properties Density Curve Density scale Viscosity scale Viscosity Curve Water density vs temperature What happens here? What happens here? Note: This plot is for SATURATED Water – Discussed soon Water and Ice Water Phase Diagram Temperature and Pressure scales • Fahrenheit: 32F water freezes 212 water boils (at atmospheric pressure) • Celsius: 0C water freezes and 100C water boils (again at atmospheric pressure) • Kelvin: 273.15 water freezes and 373.15 water boils (0K is absolute zero – All motion would stop even electrons around a nucleus) • psi (pounds per square in) one can reference absolute pressure or “gage” pressure (psia or psig) • 14.7psia is one Atmosphere • 0 Atmosphere is absolute vacuum, and 0psia and -14.7psig • Standard Temperature and Pressure (STP) is 20C (68F) and 1 atm Temperature Scales Gases– Air Air density is 1.2kg/m3 => NO Kidding! 100cm =1m Total weight
    [Show full text]
  • Cryogenicscryogenics Forfor Particleparticle Acceleratorsaccelerators Ph
    CryogenicsCryogenics forfor particleparticle acceleratorsaccelerators Ph. Lebrun CAS Course in General Accelerator Physics Divonne-les-Bains, 23-27 February 2009 Contents • Low temperatures and liquefied gases • Cryogenics in accelerators • Properties of fluids • Heat transfer & thermal insulation • Cryogenic distribution & cooling schemes • Refrigeration & liquefaction Contents • Low temperatures and liquefied gases ••• CryogenicsCryogenicsCryogenics ininin acceleratorsacceleratorsaccelerators ••• PropertiesPropertiesProperties ofofof fluidsfluidsfluids ••• HeatHeatHeat transfertransfertransfer &&& thermalthermalthermal insulationinsulationinsulation ••• CryogenicCryogenicCryogenic distributiondistributiondistribution &&& coolingcoolingcooling schemesschemesschemes ••• RefrigerationRefrigerationRefrigeration &&& liquefactionliquefactionliquefaction • cryogenics, that branch of physics which deals with the production of very low temperatures and their effects on matter Oxford English Dictionary 2nd edition, Oxford University Press (1989) • cryogenics, the science and technology of temperatures below 120 K New International Dictionary of Refrigeration 3rd edition, IIF-IIR Paris (1975) Characteristic temperatures of cryogens Triple point Normal boiling Critical Cryogen [K] point [K] point [K] Methane 90.7 111.6 190.5 Oxygen 54.4 90.2 154.6 Argon 83.8 87.3 150.9 Nitrogen 63.1 77.3 126.2 Neon 24.6 27.1 44.4 Hydrogen 13.8 20.4 33.2 Helium 2.2 (*) 4.2 5.2 (*): λ Point Densification, liquefaction & separation of gases LNG Rocket fuels LIN & LOX 130 000 m3 LNG carrier with double hull Ariane 5 25 t LHY, 130 t LOX Air separation by cryogenic distillation Up to 4500 t/day LOX What is a low temperature? • The entropy of a thermodynamical system in a macrostate corresponding to a multiplicity W of microstates is S = kB ln W • Adding reversibly heat dQ to the system results in a change of its entropy dS with a proportionality factor T T = dQ/dS ⇒ high temperature: heating produces small entropy change ⇒ low temperature: heating produces large entropy change L.
    [Show full text]
  • “Is Cryonics an Ethical Means of Life Extension?” Rebekah Cron University of Exeter 2014
    1 “Is Cryonics an Ethical Means of Life Extension?” Rebekah Cron University of Exeter 2014 2 “We all know we must die. But that, say the immortalists, is no longer true… Science has progressed so far that we are morally bound to seek solutions, just as we would be morally bound to prevent a real tsunami if we knew how” - Bryan Appleyard 1 “The moral argument for cryonics is that it's wrong to discontinue care of an unconscious person when they can still be rescued. This is why people who fall unconscious are taken to hospital by ambulance, why they will be maintained for weeks in intensive care if necessary, and why they will still be cared for even if they don't fully awaken after that. It is a moral imperative to care for unconscious people as long as there remains reasonable hope for recovery.” - ALCOR 2 “How many cryonicists does it take to screw in a light bulb? …None – they just sit in the dark and wait for the technology to improve” 3 - Sterling Blake 1 Appleyard 2008. Page 22-23 2 Alcor.org: ‘Frequently Asked Questions’ 2014 3 Blake 1996. Page 72 3 Introduction Biologists have known for some time that certain organisms can survive for sustained time periods in what is essentially a death"like state. The North American Wood Frog, for example, shuts down its entire body system in winter; its heart stops beating and its whole body is frozen, until summer returns; at which point it thaws and ‘comes back to life’ 4.
    [Show full text]
  • Cryogenic Transport Trailers
    CRYOGENIC TRANSPORT TRAILERS Worthington Industries delivers end-to-end solutions for storing and transporting cryogenic liquids. Our high- quality custom trailers are manufactured at our production facility in Theodore, Alabama. Worthington's transport trailers are customized to meet your unique needs and designed to operate for years to come, which means dependable fleets with lower transportation, maintenance and refurbishment costs. We’re always seeking new ways to increase your productivity, performance and value. Our trailers feature lightweight aluminum or stainless steel liners for the safe transportation of the specialty liquefied gases such as: • Liquid Nitrogen (LIN) • Liquid Argon (LAR) • Liquid Oxygen (LOX) • Liquid Hydrogen (LH2) • Liquid Natural Gas (LNG) OUR ENGINEERS WILL WORK WITH YOU TO DETERMINE THE BEST CONFIGURATION FOR YOUR OPERATION. LIN LAR LOX LH2 LNG Spec ATL8400-33PE ATL5150-40PH 6000STL-40PE 17900STL-165P ATL12800-70P (Engine drive) (Hydraulic drive) (Engine drive) ATL8400-33PH (Engine drive 6000STL-40PH (Hydraulic drive) available) (Hydraulic drive) ATL8400-33PL (Electrical drive) Gross Capacity (gallons) 8,400 5,150 6,000 17,900 12,800 Pressure (PSI) 33 40 40 165 70 Inner Vessel Material Alum Alum SS SS Alum Outer Vessel Material Alum Alum C or C/SS C or C/SS C or C/SS *Alum = Aluminum, SS = Stainless Steel, C = Carbon Steel ASME CERTIFIED, ASME U STAMP, NATIONAL BOARD CERTIFIED, DOT-APPROVED (#CT-13707), REPAIR OR BUILD TO MC -331, MC-338 anD CGA-341 4075 HAMILTON ROAD THEODORE, ALABAMA 36582 P: 844.273.7517 [email protected] WORTHINGTONINDUSTRIES.COM/TRANSPORTTRAILERS © 2018, Worthington Industries Inc. 07/18 CRYOGENIC TRANSPORT TRAILER REPAIRS Worthington Industries offers full rehab as well as DOT inspection and certification of cryogenic trailers in our Theodore, Alabama facility.
    [Show full text]
  • Cryogenic Liquids
    ENVIRONMENTAL HEALTH & SAFETY Cryogenic Liquids Safety Fact Sheet Fact General Cryogen Type of gas Cryogenic liquids are liquefied gases that are kept in their liquid state at very low temperatures. These liquids have boiling points below -238°F (-150°C) and are Argon (Ar) Inert gases at normal temperatures and pressures. Different cryogens become liquids under different conditions of temperature and pressure, but all have two common Helium (He) Inert properties: they are extremely cold and small amounts of the liquid can expand into very large volumes of gas. Hydrogen gas (H2) Flammable Nitrogen gas (N2) Inert Most cryogenic liquids and the gases they produce can be placed into three groups: Oxygen (O2) Oxygen Inert gases – These gases do not react chemically to any great extent and do not burn or support Methane (CH4) Flammable combustion. Carbon Monoxide Flammable gases – Produce a gas that can burn in air (CO) Flammable when ignited. Oxygen – Reacts explosively with organic materials; supports combustion. Hazards Cryogens can present one or more of the following hazards: Extreme Cold: Cryogenic liquids and their associated cold vapors and gases can produce effects on the skin similar to a thermal burn. Brief exposures can damage delicate tissues, such as the eyes. Prolonged exposure of the skin can cause a cold burn and frostbite. Asphyxiation: When cryogenic liquids form a gas, the gas is very cold and usually heavier than air; even if the gas is non-toxic, it displaces air. Oxygen deficiency (i.e. asphyxiation) can cause death and is a serious hazard in confined spaces. Toxicity: Each gas can cause specific health effects.
    [Show full text]
  • Properties of Cryogenic Insulants J
    Cryogenics 38 (1998) 1063–1081 1998 Elsevier Science Ltd. All rights reserved Printed in Great Britain PII: S0011-2275(98)00094-0 0011-2275/98/$ - see front matter Properties of cryogenic insulants J. Gerhold Technische Universitat Graz, Institut fur Electrische Maschinen und Antriebestechnik, Kopernikusgasse 24, A-8010 Graz, Austria Received 27 April 1998; revised 18 June 1998 High vacuum, cold gases and liquids, and solids are the principal insulating materials for superconducting apparatus. All these insulants have been claimed to show fairly good intrinsic dielectric performance under laboratory conditions where small scale experiments in the short term range are typical. However, the insulants must be inte- grated into large scaled insulating systems which must withstand any particular stress- ing voltage seen by the actual apparatus over the full life period. Estimation of the amount of degradation needs a reliable extrapolation from small scale experimental data. The latter are reviewed in the light of new experimental data, and guidelines for extrapolation are discussed. No degradation may be seen in resistivity and permit- tivity. Dielectric losses in liquids, however, show some degradation, and breakdown as a statistical event must be scrutinized very critically. Although information for break- down strength degradation in large systems is still fragmentary, some thumb rules can be recommended for design. 1998 Elsevier Science Ltd. All rights reserved Keywords: dielectric properties; vacuum; fluids; solids; power applications; supercon- ductors The dielectric insulation design of any superconducting Of special interest for normal operation are the resis- power apparatus must be based on the available insulators. tivity, the permittivity, and the dielectric losses.
    [Show full text]
  • Cryogenics and Ultra Low Temperatures - Yuriy M
    PHYSICAL METHODS, INSTRUMENTS AND MEASUREMENTS – Vol. III - Cryogenics and Ultra Low Temperatures - Yuriy M. Bunkov CRYOGENICS AND ULTRA LOW TEMPERATURES Yuriy M. Bunkov Centre de Recherches sur les Tres Basses Temperatures (CRTBT), Grenoble, France Keywords: absolute (Kelvin) temperature scale, absolute zero of temperature, adiabatic demagnetization, negative temperature, cryogenics, dilution refrigeration, Joule– Thomson effect, Pomeranchuk effect, superconductivity, superconductivity, superfluid 4He (He-II), superfluid 3He, low temperature physics, ultra low temperature physics, vortex line Contents 1. Introduction 2. Temperature Scales 3. History 4. The Methods of Refrigeration 4.1. Evaporation Cryostats 4.1.1. 3He Evaporation Cryostat 4.2. Dilution Refrigeration 4.3 Pomeranchuk Cooling 4.4. Adiabatic Demagnetization 5. Physics at Lower Temperatures 5.1 Low Temperatures Physics and Cosmology 6. Applications Glossary Bibliography Biographical Sketch Summary This article describes the scientific and technical aspects of low and ultra low temperatures. The article includes the historical background, explanation of temperature scales, description of different cooling methods, and the modern problems of ultra low temperature UNESCOphysics as well low temperature – applications. EOLSS 1. Introduction Cryogenics is theSAMPLE technical discipline whic hCHAPTERS studies and uses materials at very low temperatures, as well as the methods for producing low temperatures. The temperature achieved depends on the type of liquefied gas, known as “cryogens.” This word, formed from the Greek κρυοζ (cold) and γευεζ (generated from,) was introduced by Kamerlingh Onnes, who liquefied helium for the first time and who can thus be regarded as the progenitor of cryogenics as known today. The field of cryogenics involves the production and application of low temperatures in science and technology.
    [Show full text]
  • Status of the XENON Dark Matter Project Recent Results from XENON100 and Prospects for Detection with XENON1T
    Status of the XENON Dark Matter Project Recent Results from XENON100 and Prospects for Detection with XENON1T Guillaume Plante Columbia University on behalf of the XENON Collaboration DBD 2014 - Waikoloa, Hawaii - October 5-7, 2014 XENON Program XENON10 XENON100 XENON1T/XENONnT 2005-2007 2008-2015 2012-2017 / ∼2017-2022 25kg 161kg 3300kg/7000kg Achieved (2007) Achieved (2011) Projected (2017) / Projected (2022) −44 2 −45 2 −47 2 −48 2 σSI =8.8 × 10 cm σSI =7.0 × 10 cm σSI ∼ 2 × 10 cm / σSI ∼ 3 × 10 cm Achieved (2012) −45 2 σSI =2.0 × 10 cm GuillaumePlante-XENON DBD2014-Waikoloa,Hawaii-October5-7, 2014 2 / 35 XENON Collaboration GuillaumePlante-XENON DBD2014-Waikoloa,Hawaii-October5-7, 2014 3 / 35 XENON Collaboration GuillaumePlante-XENON DBD2014-Waikoloa,Hawaii-October5-7, 2014 3 / 35 Why Xenon? • Large mass number A (∼131), ex- pect high rate for SI interactions (σ ∼ A2) if energy threshold for nu- clear recoils is low 129 131 −3 A • ∼50% odd isotopes ( Xe, Xe) 10 Si ( = 28) for SD interactions Ar (A = 40) Ge (A = 73) • No long-lived radioisotopes (with the A 136 Xe ( = 131) exception of Xe, T1/2 = 2.1 × 21 10 yr), Kr can be reduced to ppt −4 10 levels • High stopping power (Z = 54, ρ = 3 g cm−3), active volume is self shielding Total Rate [evt/kg/day] −5 10 σ = 1 × 10−44 cm2 • Efficient scintillator (∼80% light χN yield of NaI), fast response 0 10 20 30 40 50 • Scalable to large target masses Eth - Nuclear Recoil Energy [keV] • Nuclear recoil discrimination with si- multaneous measurement of scintilla- tion and ionization GuillaumePlante-XENON DBD2014-Waikoloa,Hawaii-October5-7, 2014 4 / 35 Dual Phase TPC Principle • Bottom PMT array below cathode, fully immersed in LXe to efficiently detect scintillation signal (S1).
    [Show full text]
  • 3-D Modeling and Rapid Prototyping of a Cryogenic Liquefier
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by ethesis@nitr 3-D MODELING AND RAPID PROTOTYPING OF A CRYOGENIC LIQUEFIER A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF Bachelor of Technology In Mechanical Engineering By Nikhilesh Bishoyee Under the guidance of Prof. Sunil Kumar Sarangi Department of Mechanical Engineering National Institute of Technology Rourkela 2010 Page | i National Institute of Technology Rourkela CERTIFICATE This is to certify that the thesis entitled, “3 -D Modeling and Rapid Prototyping of a Cryogenic Liquefier” submitted by Mr. Nikhilesh Bishoyee in partial fulfillment of the requirements for the award of Bachelor of Technology Degree in Mechanical Engineering at the National Institute of Technology, Rourkela (Deemed University) is an authentic work carried out by him under my supervision and guidance. To the best of my knowledge, the matter embodied in the thesis has not been submitted to any other University/ Institute for the award of any degree or diploma. Place: Rourkela Prof. Sunil Kumar Sarangi Date: Department of Mechanical Engineering Director, National Institute of Technology Rourkela, 769008 P a g e | ii ACKNOWLEDGEMENT I am extremely fortunate to be involved in such an exciting and challenging research project like “ 3-D modeling and Rapid Prototyping”. This project increased my thinking and understanding capability in the field of cryogenics. I would like to express my greatest gratitude and respect to my supervisor Dr. SUNIL KUMAR SARANGI , for his excellent guidance, valuable suggestions and endless support. He has not only been a wonderful supervisor but also a genuine person.
    [Show full text]
  • Cryogenics in Space - a Review of the Missions and Technologies
    LINDER 8/29/01 9:36 AM Page 2 r bulletin 107 — august 2001 Cryogenics in Space - A review of the missions and technologies M. Linder Mechanical Engineering Department, ESA Directorate of Technical and Operational Support, ESTEC, Noordwijk, The Netherlands N. Rando, A. Peacock Space Science Department, ESA Directorate of Scientific Programmes, ESTEC, Noordwijk, The Netherlands B. Collaudin Alcatel Space Industries, Cannes, France Applications of cryogenics in space against their development and operating costs, The development, in-orbit commissioning, and and compared with alternative technologies. operation of cryogenic instrumentation in space raises the level of mission complexity, risk and Cryogenic detectors for space applications associated cost. Any application must then be Cryogenic photon detectors offer two main justified on the basis of its specific return. In the advantages over conventional sensors: case of scientific missions, the cryogenic – their much higher sensitivity (expressed by detectors and related payloads are the only the Noise Equivalent Power or NEP, i.e. the candidates for the accomplishment of the amount of incident power required to achieve mission objectives, offering unmatched a signal-to-noise ratio equal to unity) performance and unique advantages. In the – the better energy resolution (expressed in case of other applications, such as terms of resolving power, i.e. the ratio E/∆E telecommunications, the advantages offered by = λ/∆λ, with ∆E representing the full width at superconducting devices need to be evaluated half maximum of the detector response to a monochromatic excitation of energy E). Since the first liquefaction of 4He and the discovery of super- conductivity by H. Kamerlingh-Onnes (1908 and 1911), cryogenics and Cryogenic detectors have driven the utilisation its applications have come a long way.
    [Show full text]