Fundamentals of Vacuum Physics and Technology
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Glossary Physics (I-Introduction)
1 Glossary Physics (I-introduction) - Efficiency: The percent of the work put into a machine that is converted into useful work output; = work done / energy used [-]. = eta In machines: The work output of any machine cannot exceed the work input (<=100%); in an ideal machine, where no energy is transformed into heat: work(input) = work(output), =100%. Energy: The property of a system that enables it to do work. Conservation o. E.: Energy cannot be created or destroyed; it may be transformed from one form into another, but the total amount of energy never changes. Equilibrium: The state of an object when not acted upon by a net force or net torque; an object in equilibrium may be at rest or moving at uniform velocity - not accelerating. Mechanical E.: The state of an object or system of objects for which any impressed forces cancels to zero and no acceleration occurs. Dynamic E.: Object is moving without experiencing acceleration. Static E.: Object is at rest.F Force: The influence that can cause an object to be accelerated or retarded; is always in the direction of the net force, hence a vector quantity; the four elementary forces are: Electromagnetic F.: Is an attraction or repulsion G, gravit. const.6.672E-11[Nm2/kg2] between electric charges: d, distance [m] 2 2 2 2 F = 1/(40) (q1q2/d ) [(CC/m )(Nm /C )] = [N] m,M, mass [kg] Gravitational F.: Is a mutual attraction between all masses: q, charge [As] [C] 2 2 2 2 F = GmM/d [Nm /kg kg 1/m ] = [N] 0, dielectric constant Strong F.: (nuclear force) Acts within the nuclei of atoms: 8.854E-12 [C2/Nm2] [F/m] 2 2 2 2 2 F = 1/(40) (e /d ) [(CC/m )(Nm /C )] = [N] , 3.14 [-] Weak F.: Manifests itself in special reactions among elementary e, 1.60210 E-19 [As] [C] particles, such as the reaction that occur in radioactive decay. -
1 the History of Vacuum Science and Vacuum Technology
1 1 The History of Vacuum Science and Vacuum Technology The Greek philosopher Democritus (circa 460 to 375 B.C.), Fig. 1.1, assumed that the world would be made up of many small and undividable particles that he called atoms (atomos, Greek: undividable). In between the atoms, Democritus presumed empty space (a kind of micro-vacuum) through which the atoms moved according to the general laws of mechanics. Variations in shape, orientation, and arrangement of the atoms would cause variations of macroscopic objects. Acknowledging this philosophy, Democritus,together with his teacher Leucippus, may be considered as the inventors of the concept of vacuum. For them, the empty space was the precondition for the variety of our world, since it allowed the atoms to move about and arrange themselves freely. Our modern view of physics corresponds very closely to this idea of Democritus. However, his philosophy did not dominate the way of thinking until the 16th century. It was Aristotle’s (384 to 322 B.C.) philosophy, which prevailed throughout theMiddleAgesanduntilthebeginning of modern times. In his book Physica [1], around 330 B.C., Aristotle denied the existence of an empty space. Where there is nothing, space could not be defined. For this reason no vacuum (Latin: empty space, emptiness) could exist in nature. According to his philosophy, nature consisted of water, earth, air, and fire. The lightest of these four elements, fire, is directed upwards, the heaviest, earth, downwards. Additionally, nature would forbid vacuum since neither up nor down could be defined within it. Around 1300, the medieval scholastics began to speak of a horror vacui, meaning nature’s fear of vacuum. -
String-Inspired Running Vacuum—The ``Vacuumon''—And the Swampland Criteria
universe Article String-Inspired Running Vacuum—The “Vacuumon”—And the Swampland Criteria Nick E. Mavromatos 1 , Joan Solà Peracaula 2,* and Spyros Basilakos 3,4 1 Theoretical Particle Physics and Cosmology Group, Physics Department, King’s College London, Strand, London WC2R 2LS, UK; [email protected] 2 Departament de Física Quàntica i Astrofísica, and Institute of Cosmos Sciences (ICCUB), Universitat de Barcelona, Av. Diagonal 647, E-08028 Barcelona, Catalonia, Spain 3 Academy of Athens, Research Center for Astronomy and Applied Mathematics, Soranou Efessiou 4, 11527 Athens, Greece; [email protected] 4 National Observatory of Athens, Lofos Nymfon, 11852 Athens, Greece * Correspondence: [email protected] Received: 15 October 2020; Accepted: 17 November 2020; Published: 20 November 2020 Abstract: We elaborate further on the compatibility of the “vacuumon potential” that characterises the inflationary phase of the running vacuum model (RVM) with the swampland criteria. The work is motivated by the fact that, as demonstrated recently by the authors, the RVM framework can be derived as an effective gravitational field theory stemming from underlying microscopic (critical) string theory models with gravitational anomalies, involving condensation of primordial gravitational waves. Although believed to be a classical scalar field description, not representing a fully fledged quantum field, we show here that the vacuumon potential satisfies certain swampland criteria for the relevant regime of parameters and field range. We link the criteria to the Gibbons–Hawking entropy that has been argued to characterise the RVM during the de Sitter phase. These results imply that the vacuumon may, after all, admit under certain conditions, a rôle as a quantum field during the inflationary (almost de Sitter) phase of the running vacuum. -
Particle Characterisation In
LIFE SCIENCE I TECHNICAL BULLETIN ISSUE N°11 /JULY 2008 PARTICLE CHARACTERISATION IN EXCIPIENTS, DRUG PRODUCTS AND DRUG SUBSTANCES AUTHOR: HILDEGARD BRÜMMER, PhD, CUSTOMER SERVICE MANAGER, SGS LIFE SCIENCE SERVICES, GERMANY Particle characterization has significance in many industries. For the pharmaceutical industry, particle size impacts products in two ways: as an influence on drug performance and as an indicator of contamination. This article will briefly examine how particle size impacts both, and review the arsenal of methods for measuring and tracking particle size. Furthermore, examples of compromised product quality observed within our laboratories illustrate why characterization is so important. INDICATOR OF CONTAMINATION Controlling the limits of contaminating • Adverse indirect reactions: particles Particle characterisation of drug particles is critical for injectable are identified by the immune system as substances, drug products and excipients (parenteral) solutions. Particle foreign material and immune reaction is an important factor in R&D, production contamination of solutions can potentially might impose secondary effects. and quality control of pharmaceuticals. have the following results: It is becoming increasingly important for In order to protect a patient and to compliance with requirements of FDA and • Adverse direct reactions: e.g. particles guarantee a high quality product, several European Health Authorities. are distributed via the blood in the body chapters in the compendia (USP, EP, JP) and cause toxicity to specific tissues or describe techniques for characterisation organs, or particles of a given size can of limits. Some of the most relevant cause a physiological effect blocking blood chapters are listed in Table 1. flow e.g. in the lungs. -
Chapter 3 Bose-Einstein Condensation of an Ideal
Chapter 3 Bose-Einstein Condensation of An Ideal Gas An ideal gas consisting of non-interacting Bose particles is a ¯ctitious system since every realistic Bose gas shows some level of particle-particle interaction. Nevertheless, such a mathematical model provides the simplest example for the realization of Bose-Einstein condensation. This simple model, ¯rst studied by A. Einstein [1], correctly describes important basic properties of actual non-ideal (interacting) Bose gas. In particular, such basic concepts as BEC critical temperature Tc (or critical particle density nc), condensate fraction N0=N and the dimensionality issue will be obtained. 3.1 The ideal Bose gas in the canonical and grand canonical ensemble Suppose an ideal gas of non-interacting particles with ¯xed particle number N is trapped in a box with a volume V and at equilibrium temperature T . We assume a particle system somehow establishes an equilibrium temperature in spite of the absence of interaction. Such a system can be characterized by the thermodynamic partition function of canonical ensemble X Z = e¡¯ER ; (3.1) R where R stands for a macroscopic state of the gas and is uniquely speci¯ed by the occupa- tion number ni of each single particle state i: fn0; n1; ¢ ¢ ¢ ¢ ¢ ¢g. ¯ = 1=kBT is a temperature parameter. Then, the total energy of a macroscopic state R is given by only the kinetic energy: X ER = "ini; (3.2) i where "i is the eigen-energy of the single particle state i and the occupation number ni satis¯es the normalization condition X N = ni: (3.3) i 1 The probability -
Riccar Radiance
Description of the vacuum R40 & R40P Owner’s Manual CONTENTS Getting Started Important Safety Instructions .................................................................................................... 2 Polarization Instructions ............................................................................................................. 3 State of California Proposition 65 Warnings ...................................................................... 3 Description of the Vacuum ........................................................................................................ 4 Assembling the Vacuum Attaching the Handle to the Vacuum ..................................................................................... 6 Unwinding the Power Cord ...................................................................................................... 6 Operation Reclining the Handle .................................................................................................................. 7 Vacuuming Carpet ....................................................................................................................... 7 Bare Floor Cleaning .................................................................................................................... 7 Brushroll Auto Shutoff Feature ................................................................................................. 7 Dirt Sensing Display .................................................................................................................. -
The Use of a Lunar Vacuum Deposition Paver/Rover To
Developing a New Space Economy (2019) 5014.pdf The Use of a Lunar Vacuum Deposition Paver/Rover to Eliminate Hazardous Dust Plumes on the Lunar Sur- face Alex Ignatiev and Elliot Carol, Lunar Resources, Inc., Houston, TX ([email protected], elliot@lunarre- sources.space) References: [1] A. Cohen “Report of the 90-Day Study on Hu- man Exploration of the Moon and Mars”, NASA, Nov. 1989 [2] A. Freunlich, T. Kubricht, and A. Ignatiev: “Lu- nar Regolith Thin Films: Vacuum Evaporation and Properties,” AP Conf. Proc., Vol 420, (1998) p. 660 [3] Sadoway, D.R.: “Electrolytic Production of Met- als Using Consumable Anodes,” US Patent No. © 2018 Lunar Resources, Inc. 5,185,068, February 9, 1993 [4] Duke, M.B.: Blair, B.: and J. Diaz: “Lunar Re- source Utilization,” Advanced Space Research, Vol. 31(2002) p.2413. Figure 1, Lunar Resources Solar Cell Paver concept [5] A. Ignatiev, A. Freundlich.: “The Use of Lunar surface vehicle Resources for Energy Generation on the Moon,” Introduction: The indigenous resources of the Moon and its natural vacuum can be used to prepare and construct various assets for future Outposts and Bases on the Moon. Based on available lunar resources and the Moon’s ultra-strong vacuum, a vacuum deposition paver/rover can be used to melt regolith into glass to eliminate dust plumes during landing operations and surface activities on the Moon. This can be accom- plished by the deployment of a moderately-sized (~200kg) crawler/rover on the surface of the Moon with the capabilities of preparing and then melting of the lu- nar regolith into a glass on the Lunar surface. -
Introduction to the Principles of Vacuum Physics
1 INTRODUCTION TO THE PRINCIPLES OF VACUUM PHYSICS Niels Marquardt Institute for Accelerator Physics and Synchrotron Radiation, University of Dortmund, 44221 Dortmund, Germany Abstract Vacuum physics is the necessary condition for scientific research and modern high technology. In this introduction to the physics and technology of vacuum the basic concepts of a gas composed of atoms and molecules are presented. These gas particles are contained in a partially empty volume forming the vacuum. The fundamentals of vacuum, molecular density, pressure, velocity distribution, mean free path, particle velocity, conductivity, temperature and gas flow are discussed. 1. INTRODUCTION — DEFINITION, HISTORY AND APPLICATIONS OF VACUUM The word "vacuum" comes from the Latin "vacua", which means "empty". However, there does not exist a totally empty space in nature, there is no "ideal vacuum". Vacuum is only a partially empty space, where some of the air and other gases have been removed from a gas containing volume ("gas" comes from the Greek word "chaos" = infinite, empty space). In other words, vacuum means any volume containing less gas particles, atoms and molecules (a lower particle density and gas pressure), than there are in the surrounding outside atmosphere. Accordingly, vacuum is the gaseous environment at pressures below atmosphere. Since the times of the famous Greek philosophers, Demokritos (460-370 B.C.) and his teacher Leukippos (5th century B.C.), one is discussing the concept of vacuum and is speculating whether there might exist an absolutely empty space, in contrast to the matter of countless numbers of indivisible atoms forming the universe. It was Aristotle (384-322 B.C.), who claimed that nature is afraid of total emptiness and that there is an insurmountable "horror vacui". -
2. Classical Gases
2. Classical Gases Our goal in this section is to use the techniques of statistical mechanics to describe the dynamics of the simplest system: a gas. This means a bunch of particles, flying around in a box. Although much of the last section was formulated in the language of quantum mechanics, here we will revert back to classical mechanics. Nonetheless, a recurrent theme will be that the quantum world is never far behind: we’ll see several puzzles, both theoretical and experimental, which can only truly be resolved by turning on ~. 2.1 The Classical Partition Function For most of this section we will work in the canonical ensemble. We start by reformu- lating the idea of a partition function in classical mechanics. We’ll consider a simple system – a single particle of mass m moving in three dimensions in a potential V (~q ). The classical Hamiltonian of the system3 is the sum of kinetic and potential energy, p~ 2 H = + V (~q ) 2m We earlier defined the partition function (1.21) to be the sum over all quantum states of the system. Here we want to do something similar. In classical mechanics, the state of a system is determined by a point in phase space.Wemustspecifyboththeposition and momentum of each of the particles — only then do we have enough information to figure out what the system will do for all times in the future. This motivates the definition of the partition function for a single classical particle as the integration over phase space, 1 3 3 βH(p,q) Z = d qd pe− (2.1) 1 h3 Z The only slightly odd thing is the factor of 1/h3 that sits out front. -
Particle Number Concentrations and Size Distribution in a Polluted Megacity
https://doi.org/10.5194/acp-2020-6 Preprint. Discussion started: 17 February 2020 c Author(s) 2020. CC BY 4.0 License. Particle number concentrations and size distribution in a polluted megacity: The Delhi Aerosol Supersite study Shahzad Gani1, Sahil Bhandari2, Kanan Patel2, Sarah Seraj1, Prashant Soni3, Zainab Arub3, Gazala Habib3, Lea Hildebrandt Ruiz2, and Joshua S. Apte1 1Department of Civil, Architectural and Environmental Engineering, The University of Texas at Austin, Texas, USA 2McKetta Department of Chemical Engineering, The University of Texas at Austin, Texas, USA 3Department of Civil Engineering, Indian Institute of Technology Delhi, New Delhi, India Correspondence: Joshua S. Apte ([email protected]), Lea Hildebrandt Ruiz ([email protected]) Abstract. The Indian national capital, Delhi, routinely experiences some of the world's highest urban particulate matter concentrations. While fine particulate matter (PM2.5) mass concentrations in Delhi are at least an order of magnitude higher than in many western cities, the particle number (PN) concentrations are not similarly elevated. Here we report on 1.25 years of highly 5 time resolved particle size distributions (PSD) data in the size range of 12–560 nm. We observed that the large number of accumulation mode particles—that constitute most of the PM2.5 mass—also contributed substantially to the PN concentrations. The ultrafine particles (UFP, Dp <100 nm) fraction of PN was higher during the traffic rush hours and for daytimes of warmer seasons—consistent with traffic and nucleation events being major sources of urban UFP. UFP concentrations were found to be relatively lower during periods with some of the highest mass concentrations. -
Statistical Physics 06/07
STATISTICAL PHYSICS 06/07 Quantum Statistical Mechanics Tutorial Sheet 3 The questions that follow on this and succeeding sheets are an integral part of this course. The code beside each question has the following significance: • K: key question – explores core material • R: review question – an invitation to consolidate • C: challenge question – going beyond the basic framework of the course • S: standard question – general fitness training! 3.1 Particle Number Fluctuations for Fermions [s] (a) For a single fermion state in the grand canonical ensemble, show that 2 h(∆nj) i =n ¯j(1 − n¯j) wheren ¯j is the mean occupancy. Hint: You only need to use the exclusion principle not the explict form ofn ¯j. 2 How is the fact that h(∆nj) i is not in general small compared ton ¯j to be reconciled with the sharp values of macroscopic observables? (b) For a gas of noninteracting particles in the grand canonical ensemble, show that 2 X 2 h(∆N) i = h(∆nj) i j (you will need to invoke that nj and nk are uncorrelated in the GCE for j 6= k). Hence show that for noninteracting Fermions Z h(∆N)2i = g() f(1 − f) d follows from (a) where f(, µ) is the F-D distribution and g() is the density of states. (c) Show that for low temperatures f(1 − f) is sharply peaked at = µ, and hence that 2 h∆N i ' kBT g(F ) where F = µ(T = 0) R ∞ ex dx [You may use without proof the result that −∞ (ex+1)2 = 1.] 3.2 Entropy of the Ideal Fermi Gas [C] The Grand Potential for an ideal Fermi is given by X Φ = −kT ln [1 + exp β(µ − j)] j Show that for Fermions X Φ = kT ln(1 − pj) , j where pj = f(j) is the probability of occupation of the state j. -
Appendix a Review of Probability Distribution
Appendix A Review of Probability Distribution In this appendix we review some fundamental concepts of probability theory. After deriving in Sect. A.1 the binomial probability distribution, in Sect. A.2 we show that for systems described by a large number of random variables this distribution tends to a Gaussian function. Finally, in Sect. A.3 we define moments and cumulants of a generic probability distribution, showing how the central limit theorem can be easily derived. A.1 Binomial Distribution Consider an ideal gas at equilibrium, composed of N particles, contained in a box of volume V . Isolating within V a subsystem of volume v, as the gas is macroscop- ically homogeneous, the probability to find a particle within v equals p = v/V , while the probability to find it in a volume V − v is q = 1 − p. Accordingly, the probability to find any one given configuration (i.e. assuming that particles could all be distinguished from each other), with n molecules in v and the remaining (N − n) within (V − v), would be equal to pnqN−n, i.e. the product of the respective prob- abilities.1 However, as the particles are identical to each other, we have to multiply this probability by the Tartaglia pre-factor, that us the number of possibilities of 1Here, we assume that finding a particle within v is not correlated with finding another, which is true in ideal gases, that are composed of point-like molecules. In real fluids, however, since molecules do occupy an effective volume, we should consider an excluded volume effect.