Дисертації з теми "Vacuum Measurement"
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Hoagland, David Wayne. "Continuous Permeability Measurement During Unidirectional Vacuum Infusion Processing." BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/6457.
Повний текст джерелаKonno, T., L. Ren, G. Piao, García J. M. Juárez, F. M. Suárez, S. J. Jimenez-Sandoval, T. Wakahara, K. Miyazawa, and E. M. Ferreira. "Raman Spectroscopic Measurement of a Vacuum-Deposited C60 Thin Film." Thesis, Sumy State University, 2015. http://essuir.sumdu.edu.ua/handle/123456789/42804.
Повний текст джерелаAl-Rawi, S. A. N. "Silicon sublimation at ultra high vacuum with microprocessor monitoring and measurements." Thesis, University of Kent, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382189.
Повний текст джерелаTaghvaei, Mohammad. "Interface circuitry design for a MEMS resonator-based vacuum measurement system." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=106505.
Повний текст джерелаCe travail présente la conception de circuits d'interface, pour la mesure de pression sous vide à l'aide de résonateurs MEMS. Deux nouvelles structures de systèmes de mesure sont proposées. Les spécifications requises, ainsi que la conception des blocs composants pour chaque structure, sont étudiées en détail. Par la suite, l'opération adéquate et les spécifications de performance pour les deux architectures - conçues par la technologie CMOS de IBM à 0.13 μm - sont présentées par une combinaison de simulations post-layout et de résultats mesurés. De plus, les avantages et inconvénients de chaque structure sont évalués en détail, suivis d'une comparaison avec des systèmes commerciaux similaires présentement disponibles sur le marché. Finalement, pour s'approcher du but ultime de construire le meilleur système intégré et monolithique de mesure de pression sous vide, à faible consommation de puissance et avec compensation pour les variations thermiques, les possibilités d'améliorations futures et d'extension sont discutées.
Talib, Zeeshan. "Investigation of Fast High Voltage PDC Measurement based on a Vacuum Reed-switch." Thesis, KTH, Elektroteknisk teori och konstruktion, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-91924.
Повний текст джерелаChew, Andrew David. "A rotating disc gauge for absolute total pressure measurement in a high vacuum." Thesis, University of York, 1993. http://etheses.whiterose.ac.uk/10874/.
Повний текст джерелаLun, Jonathan. "Development of a vacuum arc thruster for nanosatellite propulsion." Thesis, Stellenbosch : University of Stellenbosch, 2008. http://hdl.handle.net/10019.1/1527.
Повний текст джерелаThis thesis describes the development of a vacuum arc thruster (VAT) to be used as a potential low mass (< 500 g), low power (< 5–10W) propulsion system for nanosatellites. The thruster uses a high voltage capacitive circuit to initiate and power the arc process with a 400 ns high current (150–800A) pulse. A one-dimensional steady state analyticalmodel describing the cathode region of the vacuum arc was developed. The model made use of mass and energy balances at the sheath region and cathode surface respectively to predict key quantities such as thrust, ion velocity, ion-to-arc current ratio and erosion rate. Predicted results were shown to be within the limits of reported literature (∼63 μN/A, 26.12 km/s, 0.077 and 110 μg/C respectively). A sensitivity analysis of the analytical model found that a high electric field in the cathode region impedes and decelerates ion flow, which is used for thrust. This was confirmed experimentally for thrust values at arc voltages greater than 2000 V. Both direct and indirect means of measuring thrust were achieved by using a deflecting cantilever beam and an ion collector system, respectively. The transient response of the cantilever beam to impulsive thrust was analytically modeled, whilst the ion current was found by measuring the current induced on a plate subject to ion bombardment. Knowledge of the ion current density distribution was successfully used to approximate the effective normal thrust vector. Direct and indirect thrust levels were roughly 140 and 82 μN/A of average arc current, respectively. Measured thrust was found to be higher than predicted thrust due to thrust contributions fromthe ablation of Teflon insulation. The discrepancy is also due to the uncertainty in quantifying free parameters in the analytical model such as the fraction of generated ions flowing away from the cathode region. The thrust-topower ratio, specific impulse and efficiency of the vacuum arc thruster at an average arc current of 200 A was measured to be 0.6 μN/W, 160 s and 0.05 %, respectively. A thruster performance analysis and specification showed that the VAT is capable of achieving specific orbital and slew manoeuvres within a constant 5–10 W average power. It was concluded that thruster performance could be improved by using a two-stage arc circuit consisting of a high voltage, low current, short pulse trigger and a low voltage, high current, long pulse driver.
Nagai, Hisao, Mineo Hiramatsu, Masaru Hori, and Toshio Goto. "Measurement of oxygen atom density employing vacuum ultraviolet absorption spectroscopy with microdischarge hollow cathode lamp." American Institute of Physics, 2003. http://hdl.handle.net/2237/7098.
Повний текст джерелаHannibal, Paul. "Compressibility Measurement and Modeling to Optimize Flow Simulation of Vacuum Infusion Processing for Composite Materials." BYU ScholarsArchive, 2015. https://scholarsarchive.byu.edu/etd/4433.
Повний текст джерелаChapanian, Rafi. "Study of accumulation of gases in vacuum systems: Measurement of gas transport properties of polymeric films." Thesis, University of Ottawa (Canada), 2004. http://hdl.handle.net/10393/26598.
Повний текст джерелаTina, Monteiro Shelsea. "Real Time Measurement of Dirt Pick-up by a Robotic Vacuum Cleaner using Light Sensing Technology." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-254349.
Повний текст джерелаAtt städa hemmet är en av de mest tråkiga och tidskrävande uppgifterna i en persons liv. Mycket tid kan sparas och användas bättre om dessa uppgifter kan automatiseras. Robotdammsugare som städar golvet i hemmet är en av de mest använda inhemska robotarna, då dessa robotar har möjlighet att rengöra hela huset nästan autonomt med liten eller ingen mänsklig intervention. De flesta av dessa robotar har dock inte ett system för att rapportera realtidsupphämtning av smuts som kan vara användbart, då användaren kan få reda på vilka delar av huset som är smutsiga och då ha möjlighet att undersöka orsaken bakom. Denna information kan också vara användbart för roboten för att bestämma effektiva rengöringsmönster baserat på lokalisering av smuts i huset. I denna avhandling utvecklades en prototyp för att mäta upptagning av smuts i realtid av en robotdammsugare. Den använder IR-teknik för att mäta mängden smuts som hämtas upp och kan därmed använda informationen för att avgöra vilka delar av huset som är smutsigare än andra. Signalerna kan också potentiellt användas för att förstå storleken på smuts som tas upp. Forskning av olika tekniker utfördes för att kunna välja den mest lämpliga. Systemet testades därefter och slutsatser gjordes avseende dess prestanda. Ytterligare utredningar och förbättringar som kan genomföras har också föreslagits som framtida arbete.
Karami, Peyman. "Robust and Durable Vacuum Insulation Technology for Buildings." Doctoral thesis, KTH, Byggnadsteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176494.
Повний текст джерелаDagens byggnader ansvarar för omkring 40% av världens energianvändning och står också för en väsentlig del av utsläppen av växthusgaser. I Sverige kan ca 21 % av energianvändningen relateras till förluster genom klimatskalet. Miljonprogrammet är ett namn för omkring en miljon bostäder som byggdes mellan 1965 och 1974, och många av dessa byggnader har en dålig energiprestanda efter dagens mått. Huvudsyftet med denna studie har varit att utforska möjligheterna att använda vakuumisoleringspaneler (VIP:ar) i byggnader med viss fokus på tillämpning i Miljonprogrammets byggnader. Med en värmeledningsförmåga som är ca 8 - 10 gånger bättre än för traditionell isolering erbjuder VIP:arna unika möjligheter till förbättrad termisk prestanda med minimal isolerings tjocklek. Denna avhandling hade tre huvudsyften. Det första var att undersöka nya alternativ för kärnmaterial som bland annat kan reducera kostnaden vid produktion av VIP:ar. Tre nyutvecklade nanoporösa kiselpulver har testats med olika stationära och transienta metoder. En inom projektet utvecklad testbädd som kan anslutas till TPS instrument (Transient Plane Source sensor), har använts för att mäta värmeledningsförmågan hos kärnmaterial för VIP:ar, vid varierande gastryck och olika mekaniska laster. Slutsatsen blev att transienta metoder är mindre lämpliga för utföra mätningar av värmeledningsförmåga för nanoporösa kiselpulver låg densitet. Avvikelsen i resultaten är dock minimal för densiteter ovan en gräns då värmeledningen genom fasta material blir dominerande jämfört med värmeöverföring genom strålning. Det andra syftet har varit att föreslå ett nytt monteringssystem för VIP:ar som kan användas för att förbättra energieffektiviteten i byggnader som är typiska för Miljonprogrammet. Genom parametrisk analys och dynamiska simuleringar har vi kommit fram till ett förslag på ett nytt monteringssystem för VIP:ar som har utvärderats genom fullskaleförsök i klimatkammare. Resultaten från fullskaleförsöken visar att den nya tekniska lösningen förbättrar väggens U-värde med upp till 56 %. En förbättrad värmegenomgångskoefficienten för väggen i mitten av en VIP blev mellan 0.118 till 0,132 W m-2K-1 och värmeledningstalet centre-av-panel 7 mW m-1K-1 uppnåddes. Detta arbete innehåller dessutom en ny metod för att mäta köldbryggor i anslutningar med hjälp av infraröd termografi. En effektiv värmeledningsförmåga för 10.9 mW m-1K-1 uppnåddes. Resultaten tyder även på att den verkliga termiska prestandan av VIP:ar i konstruktioner är något sämre än mätvärden för paneler i laboratorium. En effektiv värmeledningsförmåga av 10.9 mW m-1K-1 ger dock väggkonstruktionen en utmärkt termisk prestanda. Det tredje syftet har varit att bedöma miljöpåverkan av en VIP-isolerad byggnad, från produktion till drift, eftersom en livscykelanalys av hela byggnader som är isolerade med vakuumisoleringspaneler inte har gjorts tidigare. Slutsatsen var att VIP:ar har en större miljöpåverkan än traditionell isolering, i alla kategorier förutom ozonnedbrytande potential. VIP:ar har en mätbar påverkan på de totala utsläppen av växthusgaser och primärenergianvändningen i byggnader när både produktion och drift beaktas. Miljöpåverkan av de använda VIP:arna är dock positiv jämfört med GWP av en standardbyggnad (en minskning med 6 %) medan primärenergianvändningen ökade med 20 %. Slutsatsen var att ytterligare användning av VIP:ar gynnas av reducerad energiförbrukning och alternativa energikällor i produktionen av nanoporösa kiselpulver medan användningen av alternativa kärnmaterial och återvinning av VIP kärnor kan hjälpa till att minska miljöpåverkan. En känslighetsanalys visade att valet av VIP:ar har en betydande inverkan på miljöpåverkan, vilket ger möjlighet att reducera den totala användningen av primärenergi i en byggnad med 12 % och utsläppen av växthusgaser kan vara minska, så mycket som 11 % när det gäller både produktion och drift under 50 år. Avslutningsvis är det möjligt att dra slutsatsen att VIP:ar är ett mycket konkurrenskraftigt alternativ för att isolera byggnader som är typiska för Miljonprogrammet. Dock krävs ytterligare undersökningar för att minimera de mätbara miljöeffekter som förvärvats i denna LCA-studie för VIP-isolerade byggnader.
QC 20151109
Simulations of heat and moisture conditions in a retrofit wall construction with Vacuum Insulation Panels
Textural and thermal conductivity properties of a low density mesoporous silica material
A study of the thermal conductivity of granular silica materials for VIPs at different levels of gaseous pressure and external loads
Evaluation of the thermal conductivity of a new nanoporous silica material for VIPs – trends of thermal conductivity versus density
A comparative study of the environmental impact of Swedish residential buildings with vacuum insulation panels
ETICS with VIPs for improving buildings from the Swedish million unit program “Miljonprogrammet”
Agyare, Benjamin A. "INVESTIGATION OF ATOMIC MOTION IN OPTICAL LATTICES VIA INTENSITY CORRELATION MEASUREMENT." Miami University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=miami1186171967.
Повний текст джерелаYaselli, Ignacio. "Studying the time response of a vacuum phototriode and measurement of gamma radiation damage to high voltage capacitors and resistors." Thesis, Brunel University, 2008. http://bura.brunel.ac.uk/handle/2438/3018.
Повний текст джерелаEJLLI, Aldo. "PROGRESS TOWARDS A FIRST MEASUREMENT OF THE MAGNETIC BIREFRINGENCE OF VACUUM WITH A POLARIMETER BASED ON A FABRY-PEROT CAVITY." Doctoral thesis, Università degli studi di Ferrara, 2017. http://hdl.handle.net/11392/2488036.
Повний текст джерелаQuesto lavoro di tesi è stato realizzato nell'ambito dell'esperimento PVLAS, che ha l'obiettivo finale di misurare la birifrangenza magnetica del vuoto. L’esperimento è finanziato dall’INFN e dal MIUR. La birifrangenza magnetica del vuoto, così come lo scattering fotone-fotone, sono previsti dall'Elettrodinamica Quantistica (QED): questi effetti, studiati già a partire dal 1936 da Euler, Heisenberg e Weisskopf, sono associati alle fluttuazioni delle coppie elettrone-positrone nel vuoto. Per un campo magnetico di 2.5 T, la birifrangenza magnetica indotta è: ∆n(EHW) = 2.47 × 10^−23 @ 2.5 T. Si tratta quindi di un effetto estremamente piccolo che è ancora in attesa di una conferma sperimentale diretta. Questo lavoro di tesi riguarda principalmente il nuovo ellissometro ad altissima sensibilità dell’esperimento PVLAS. L'ellissometro è formato da una coppia di polarizzatori incrociati, una cavità Fabry-Perot ad altissima finesse (F = 7 × 10^5), ed utilizza la tecnica eterodina per minimizzare gli effetti di rumore e sistematici. Per rendere il vuoto birifrangente si fa uso di due magneti dipolari rotanti caratterizzati complessivamente dal parametro integrale del B^2 dl = 10.25 T2m. Nel corso del mio lavoro di tesi ho caratterizzato l’apparato sperimentale, ho studiato le sorgenti di segnali spuri, e quelle di rumore in eccesso presente nel polarimetro. Come sorgente principale di segnali spuri è stata individuata la luce diffusa modulata dall’accoppiamento meccanico tra tubo e magnete. Nella tesi descrivo i metodi utilizzati per minimizzare questo accoppiamento magnetomeccanico, così come altri rumori ed effetti sistematici. I miglioramenti così ottenuti hanno permesso di acquisire dati per periodi piuttosto lunghi – dell'ordine di qualche settimana – e ciò ha permesso di migliorare i limiti attualmente esistenti sulla birifrangenza magnetica del vuoto, raggiungendo un livello di rumore (1σ c.l.) ∆n(PVLAS) = (12 ± 17)×10^−23 @ 2.5 T, che è un fattore 7 al di sopra dell'obiettivo costituito dalla previsione della QED. Per arrivare al livello della previsione della QED si dovrà migliorare la sensibilità almeno di un fattore 10. La causa del rumore, che è in eccesso di un fattore 50 rispetto al budget teorico previsto, è tuttora ignota. Sperimentalmente si osserva che il rumore ha un andamento ≈ 1/ f^α con un valore di α compreso tra 0.5 a 1. Il problema del rumore a larga banda è comune a tutti gli apparati, passati e presenti, che vogliono misurare la birifrangenza magnetica del vuoto. L’esame delle sensibilità di questi esperimenti e l'andamento spettrale del rumore sembrano suggerire che il limite possa essere dovuto ad un rumore termico dello specchio. Queste osservazioni, a cui ho contribuito con il mio lavoro di tesi, forse consentiranno di arrivare ad una nuova comprensione del rumore residuo e allo sviluppo di nuovi metodi sperimentali.
Wang, L. L. "Precision measurement of the e+e− → π + π−(γ ) cross-section with ISR method". Phd thesis, Université Paris Sud - Paris XI, 2009. http://tel.archives-ouvertes.fr/tel-00419963.
Повний текст джерелаKlempner, Adam R. "Development of a modular interferometric microscopy system for characterization of MEMS." Link to electronic thesis, 2007. http://www.wpi.edu/Pubs/ETD/Available/etd-010407-173332/.
Повний текст джерелаKeywords: vacuum; shape and deformation measurement; MEMS; vibrometry; scanning white light; Interferometry; thermal; vibration. Includes bibliographical references (136-139 leaves ).
Pilný, Lukáš. "Vysokorychlostní vrtání plechů z hliníkových slitin." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229848.
Повний текст джерелаMatei, Dinu Gheorghe. "Corrosion generated hydrogen flux measurements using a vacuum gradient." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0019/MQ48065.pdf.
Повний текст джерелаSawyer, Samuel Thomas. "Experimental Studies of Spacecraft Plasma Interactions: Facility Characterization and Initial Measurements." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/33714.
Повний текст джерелаMaster of Science
Peterson, Joshua T. Knowlton S. F. "Vacuum magnetic flux surface measurements made on the compact toroidal hybrid." Auburn, Ala., 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SUMMER/Physics/Dissertation/Peterson_Joshua_48.pdf.
Повний текст джерелаHofman, Jiří. "Testovací metody pro hodnocení radiačních efektů v přesných analogových a signálově smíšených obvodech pro aplikace v kosmické elektronice." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2019. http://www.nusl.cz/ntk/nusl-401588.
Повний текст джерелаSasaki, K., Y. Kawai, and K. Kadota. "Vacuum ultraviolet absorption spectroscopy for absolute density measurements of fluorine atoms in fluorocarbon plasmas." American Institute of Physics, 1997. http://hdl.handle.net/2237/6989.
Повний текст джерелаRussell, Scott A. "Strain gauge measurements of blade resonance using eddy current excitation in a vacuum spin pit." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02sep%5FRussell.pdf.
Повний текст джерелаThesis advisor(s): Raymond P. Shreeve, Garth V. Hobson. Includes bibliographical references (p. 93). Also available online.
Wilson, Simon J. "Thermal profiles in oxygen vacuum swing adsorption (VSA) : modelling, observations and optimisation." Monash University, Dept. of Chemical Engineering, 2001. http://arrow.monash.edu.au/hdl/1959.1/7766.
Повний текст джерелаHerranz, Alvarez Juan F. "Minimisation of the wire position uncertainties of the new CERN vacuum wire scanner." Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/398303.
Повний текст джерелаLa producción de partículas de un acelerador se caracteriza por las especies de partículas aceleradas, por su número y energía. La tasa de partículas se determina a partir de la sección transversal de producción, una constante natural, y de un parámetro que depende del acelerador, la luminosidad. La luminosidad es proporcional al número de partículas por haz e inversamente proporcional a la dimensión transversal de los haces. La luminosidad aumenta con la densidad de partículas y por lo tanto también aumenta la probabilidad de interacciones entre los haces. Para optimizar la sección trasversal del haz, se utilizan monitores de perfil de haz. Diversos tipos de monitores pueden proporcionar mediciones del perfil transversal del haz (Escáneres de hilo, Monitores de luz de sincrotrón, Monitores de análisis de gas residual), sin embargo el escáner de hilo está considerado como el más preciso de todos ellos. Los escáneres de hilo miden el perfil del haz atravesándolo con un hilo muy delgado de manera intermitente. En los próximos años la luminosidad del Gran Colisionador de Hadrones (LHC) se incrementará de manera significativa, por lo que serán necesarios sistemas de medida de perfil de haz más precisos que lo actuales. Las nuevas características, requerirán velocidad de desplazamiento del hilo de hasta 20 ms-1 y una precisión en la medida de posición del hilo de tan solo unas micras. Los escáneres actuales no pueden alcanzar estos requerimientos ya que su precisión está limitada por el sistema de motorización, por el medidor angular de posición que está situado fuera del tanque de vacío y por las vibraciones del hilo, la cuales han sido identificadas como una de las mayores fuentes de error a la hora de conocer la posición real del hilo. Por todo esto, el desarrollo de un nuevo dispositivo cuyas características cumplan los nuevos requerimientos era necesario. Este trabajo de tesis tiene como objetivo proporcionar criterios adecuados para el diseño y operación de un nuevo escáner, con el fin de minimizar las incertidumbres en la posición del hilo. Para lograr estos objetivos, el entender las vibraciones del hilo en un sistema de este tipo es un objetivo primordial. De manera más específica el desarrollo de sistemas de medida de vibración adecuados y la construcción de modelos dinámicos del sistema son los dos objetivos concretos perseguidos por este trabajo. De cara al nuevo diseño, este trabajo pretende proponer un diseño conceptual así como definir los criterios para la optimización de las partes más críticas y establecer un procedimiento de operación que permita al nuevo dispositivo alcanzar los requerimientos impuestos por las futuras condiciones del LHC.
Dürndorfer, Mario [Verfasser]. "Thermal Micro Sensors for Pressure Measurements in the High, Fine and Rough Vacuum Ranges / Mario Dürndorfer." München : Verlag Dr. Hut, 2017. http://d-nb.info/1140977679/34.
Повний текст джерелаZia, Azhar. "Solid-state dye-sensitized solar cells measurements at different pressures and temperatures in a controlled vacuum chamber." Thesis, Uppsala universitet, Institutionen för fysik och astronomi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-211099.
Повний текст джерелаEverett, E. Addison. "Design and Characterization of a Time-of-Flight Mass Spectrometer for Composition Measurements in the Upper Atmosphere." DigitalCommons@USU, 2017. https://digitalcommons.usu.edu/etd/5698.
Повний текст джерелаBeermann, Rüdiger [Verfasser]. "Structured Light Sensor with Affine Stereo Camera Pair for Geometry Measurements of High-Temperature Components in Rough Vacuum / Rüdiger Beermann." Garbsen : TEWISS - Technik und Wissen GmbH, 2021. http://d-nb.info/1229012583/34.
Повний текст джерелаRadeck, Désirée [Verfasser]. "Nuclear Structure Studies in the A ~ 100 Mass Region including g-Factor Measurements using Nuclear Deorientation of Recoils into Vacuum / Désirée Radeck." München : Verlag Dr. Hut, 2013. http://d-nb.info/1035050072/34.
Повний текст джерелаRimbaud, Christian. "Contribution aux mesures physiques utilisant une source modulée de rayonnement appliquée aux installations nucléaires." Grenoble 1, 1987. http://www.theses.fr/1987GRE10005.
Повний текст джерелаHärtel, Martin [Verfasser], and Thomas M. [Akademischer Betreuer] Klapötke. "Studies towards the gas-phase detection of hazardous materials by vapor pressure measurements with the transpiration method in combination with vacuum outlet GC/MS / Martin Härtel ; Betreuer: Thomas M. Klapötke." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2017. http://d-nb.info/1144857244/34.
Повний текст джерелаBilgen, Suheyla. "Dynamic pressure in particle accelerators : experimental measurements and simulation for the LHC." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASP020.
Повний текст джерелаUltra-High Vacuum is an essential requirement to achieve design performances and high luminosities in high-energy particle colliders. Consequently, the understanding of the dynamic pressure evolution during accelerator operation is fundamental to provide solutions to mitigate pressure rises induced by multiple-effects occurring in the vacuum chambers and leading to beam instabilities. For the LHC, the appearance of instabilities may be due to the succession of several phenomena. First, the high intensity proton beams ionize the residual gas producing positive ions (mainly H₂⁺ or CO⁺) as well as accelerated electrons which impinge the copper wall of the beam pipe. Then, these interactions induce: (i) the desorption of gases adsorbed on the surfaces leading to pressure rises; (ii) the creation of secondary particles (ions, electrons). In this latter case, the production of secondary electrons leads to the so-called “Electron Cloud” build-up by multipacting effect, the mitigation of which being one of the major challenges of the LHC storage ring. Electron clouds generate beam instabilities, pressure rises and heat loads on the walls of beam pipe and can lead to “quench” of the superconducting magnets. All these phenomena limit the maximum intensity of the beams and thus the ultimate luminosity achievable in a proton accelerator. This work aims to investigate some fundamental phenomena which drive the dynamic pressure in the LHC, namely the effects induced by electrons and ions interacting with the copper surface of the beam screens on the one hand and the influence of the surface chemistry of copper on the other hand. First, in-situ measurements were performed. Electron and ion currents as well as pressure were recorded in situ in the Vacuum Pilot Sector (VPS) located on the LHC ring during the RUN II. By analyzing the results, more ions than expected were detected and the interplay between electrons, ions and pressure changes was investigated. Then, the ion-stimulated desorption was studied, using a devoted experimental set-up at the CERN vacuum Lab. The influence of the nature, mass, and energy of the incident ions interacting with the copper surface on the ion-desorption yields was discussed. In addition, extensive surface analyses were performed in the IJCLab laboratory to identify the role played by the surface chemistry on the electron emission yield, surface conditioning processes and the stimulated gas desorption. The fundamental role of the surface chemical components (contaminants, presence of carbon and native oxide layers) on the secondary electron yield was evidenced. Finally, we proposed a simulation code allowing to predict the pressure profiles in the vacuum chambers of particle accelerators as well as their evolution under dynamic conditions (i.e. as a function of time). This new simulation code called DYVACS (DYnamic VACuum Simulation) is an upgrade of the VASCO code developed at CERN. It was applied to simulate the dynamic pressure in the VPS when proton beams circulate into the ring. The electron cloud build-up was implemented in the code via electron cloud maps. The ionization of the residual gas by electrons was also considered. Results obtained with the DYVACS code are compared to pressure measurements recorded during typical fills for physics and a good agreement is obtained. This PhD study has provided interesting results and has allowed the development of new experimental and simulation tools that will be useful for further investigations on the vacuum stability of future particle accelerators such as HL-LHC or FCC (ee and hh)
LORENZATI, ALICE. "Super Insulating Materials for energy efficient buildings: thermal performance and experimental uncertainty." Doctoral thesis, Politecnico di Torino, 2018. http://hdl.handle.net/11583/2711530.
Повний текст джерелаTerschlüsen, Joachim A. "Constructing and Commissioning HELIOS – A High Harmonic Generation Source for Pump-Probe Measurements with sub 50 fs Temporal Resolution : The Development of Experimental Equipment for Extreme Ultraviolet Spectroscopy." Doctoral thesis, Uppsala universitet, Molekyl- och kondenserade materiens fysik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-281298.
Повний текст джерелаMüller, Jan. "Kondenzační technika a odvody spalin." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-226844.
Повний текст джерелаRuess, Frank Joachim Physics Faculty of Science UNSW. "Atomically controlled device fabrication using STM." Awarded by:University of New South Wales. Physics, 2006. http://handle.unsw.edu.au/1959.4/24855.
Повний текст джерелаTsai, Chien-Chuan, and 蔡健全. "Investigation on Vibration Measurement procedure of Vacuum Pump Equipment." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/13069606490620189108.
Повний текст джерела國立中興大學
機械工程學系所
97
This text takes Edwards vacuum pumps as the instance to analyze and illustrate the standard operational procedure for executing the regular examination and maintenance. Using vibration spectrum analyzer measures the vibration of the vacuum pumps in order to diagnose and analyze the examined equipment. Through the progress of the measurement by vibration spectrum analyzer and the result from the diagnosis and analysis, a standard procedure for examining vibration and a method for troubleshooting are established. In addition, using the application of measuring vibration and the standard operational procedure for executing the regular examination and maintenance in the semiconductor factories is also discussed in this text. Each factory can establish its own work flow for regular equipment examination and maintenance during the manufacturing process. They even can further develop or standarize other types of work flow for the equipment examination. Compared with the loss caused by unexpected machinery breakdown, the annual costs that the internal industries spend on servicing and mantaining their rotational mechanical equipment are actually much cheaper. Therefore, in default of proper maintainance or failing to control the use status of equipment, it may end in the machinery damaged even the breakdown and that will really cost the internal industries a lot of money.
Jian, Jia-xian, and 簡嘉賢. "Fabrication and Measurement of CMOS MEMS-Based Thermoelectric Vacuum Sensor." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/48574613951290320930.
Повний текст джерела國立高雄應用科技大學
光電與通訊工程研究所
102
This paper presents the measurement and the fabrication of thermocouple vacuum sensors fabricated by a low cost CMOS process and MEMS technology. The thermocouple vacuum sensors have two types of suspended structures with different solid thermal conductance. The vacuum sensor with shorter supporting leads and larger solid conductance was named TP401 and the other one was TP402. Each suspended structure was formed by using <100> silicon anisotropic etching process after the CMOS process and has a polysilicon heater and an aluminum/polysilicon thermocouple pair. The polysilicon heater also serves as a thermistor temperature sensor. The performances of the sensors were characterized in this work. Furthermore, an AC electrical modulation method using a lock-in amplifier was adopted for improving the signal-to-noise ratio of the measurement of the sensors. The thermal conductance of TP401 and TP402 were evaluated as 73.83uW/K and 79.2uW/K according to the ratio of bias heating power to temperature difference between the hot junction and the cold junction of the thermocouple. The thermocouple output voltage was about 13mV as the power of heater was 2.5mW. The thermal time constants of these sensors were also figured out by adopting the measurement of infrared frequency response of the thermocouple vacuum sensors in air and in vacuum respectively. The measurement results show that the thermal time constants of TP402 were 15ms and 220ms at atmospheric pressure and in vacuum environment respectively. The pressure response measurement of the vacuum sensors using DC bias will result in an 8-10mV voltage fluctuation and lower the signal-to-noise ratio. The signal fluctuation could be improved to 0.3mV by using an AC electrical modulation.
Almeida, Pedro Gonçalo Dias de. "Cylindrical spinning rotor gauge — A new approach for vacuum measurement." Master's thesis, 2015. http://hdl.handle.net/10362/15999.
Повний текст джерелаLin, Che-Yu, and 林哲宇. "Development of clamped-clamped beam type piezoelectric sensor for vacuum pressure measurement." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/45619720375140636940.
Повний текст джерела國立中興大學
機械工程學系所
100
In this thesis, a clamped-clamped beam type piezoelectric vacuum pressure sensor was developed. The piezoelectric beam fixed at both ends consists of a PZT layer perfectly bonded to the copper substrate. The dimensions of the PZT layers and copper substrate are both 20mm × 5mm × 200μm. Two pairs of electrodes cover the surfaces of the PZT at the bottom and top layers near both ends. Input voltage was applied at one pair of electrodes to vibrate piezoelectric beam and output voltage was measured at the other pair of electrodes. Experimental results showed that developed pressure sensor has a wide range from 6.5×10-6 to 760Torr. Output voltage generated by vibrations of beams which were varied by viscous gas damping forces acting on the beams in the vacuum. Damping forces can be calculated from damping ratio by half power method experimentally. Damping ratio of sensor includes the effect of strain rate damping and viscous gas damping. The strain rate damping is assumed to be proportional to the bonding stiffness of beam and gas damping is assumed to be changed by the pressure. Experimental results showed that output voltages of sensors were proportional to gas damping ratio. It indicated vacuum pressures can be estimated from output voltage. Vacuum pressures of nitrogen and argon are also compared. Experimental results showed that the gas damping ratio of argon is greater than the damping ratio of nitrogen. Piezoelectric outputs and damping ratios are in the same trend with the vacuum pressures.
Liao, Yi-Kai, and 廖釔凱. "Magneto-optical Kerr Effect Measurement with Pulsed Magnetic Field in High Vacuum." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/djn3a6.
Повний текст джерела中原大學
物理研究所
106
The surface magneto-optical Kerr effect measurement in high vacuum was performed with a millisecond-pulsed magnetic field, which is generated from the controlled discharge of capacitors to the coils. The theoretical simulation is used to obtain the strong and uniform pulsed magnetic field. Compared with the conventional electromagnet, pulsed magnetic field is faster. The maximum field strength can be improved by increasing the charging voltage. A nickel film on the SiO2 is used as the test sample, and its magnetic hysteresis loop was successfully obtained. The magnetic coercive, remanence, and hysteresis curve characteristics of the magnetic film were observed. The results were consistent with the measurement methods of other periodicals. Verify the accuracy of this device measurement. This technique can be applied to the study of the dynamic magnetic properties in the future.
Dhruva, Shirhatti Vijay. "Development of Graphene Based Sensors for Human Physiological Monitoring and Vacuum Measurement." Thesis, 2021. https://etd.iisc.ac.in/handle/2005/5412.
Повний текст джерелаChen, Cheng-Li, and 陳政利. "Development and Electrical Measurement of Vacuum Spacers for Field Emission Flat Panel Displays." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/82081610427665408589.
Повний текст джерела國立交通大學
工學院半導體材料與製程設備學程
99
Field-emission flat panel displays (FE-FPD) require a high-vacuum operation condition to optimize the life-time of electron field-emitters; this requirement needs vacuum spacers to be placed between the cathode plate comprising field-emitters and the screen plate to withstand the atmospheric pressure. Vacuum spacers are made of insulators so that the cathode and the screen plates are free from electrical breakdown. However, as the field-emitted electrons from the cathode strike the screen plate, backscattered electrons may impinge on the insulating spacers resulting in secondary electron (SE) emission from the spacers. Because the SE yield is larger than one for most materials, the SE emission will render the spacers positively charged, thereby modifying the local electric field; the modification can change the trajectory of the field-emitted electrons resulting in image distortion. To overcome the adverse effect of the SE emission, we fabricated porous coatings anodic aluminum oxide (AAO) and porous TiO2 thin films on glass to minimize the SE yield of the spacer. Because the porous structure can trap secondary electrons, which have a low kinetic energy and a very shallow escape depth, the SE yield can be significantly reduced. We studied the relative SE yield of the two types of spacers in an Auger electron spectrometer using a specially designed sample holder. The surface roughness, the adhesion strength and the electrical resistance of the coatings were also studied. The porous coatings demonstrated good electrical and mechanical properties, which are suitable for the use of vacuum spacers in FE-FPDs。We have successfully fabricated uniform porous AAO and porous TiO2 coatings on the large substrate with a surface area of 24 x 60 mm2.
Gleason-Rohrer, David Charles. "Measurement of the Band Bending and Surface Dipole at Chemically Functionalized Si(111)/Vacuum Interfaces." Thesis, 2014. https://thesis.library.caltech.edu/8032/1/GleasonRohrer2013thesis.pdf.
Повний текст джерелаThe core-level energy shifts observed using X-ray photoelectron spectroscopy (XPS) have been used to determine the band bending at Si(111) surfaces terminated with Si-Br, Si-H, and Si-CH3 groups, respectively. The surface termination influenced the band bending, with the Si 2p3/2 binding energy affected more by the surface chemistry than by the dopant type. The highest binding energies were measured on Si(111)-Br (whose Fermi level was positioned near the conduction band at the surface), followed by Si(111)-H, followed by Si(111)-CH3 (whose Fermi level was positioned near mid-gap at the surface). Si(111)-CH3 surfaces exposed to Br2(g) yielded the lowest binding energies, with the Fermi level positioned between mid-gap and the valence band. The Fermi level position of Br2(g)-exposed Si(111)-CH3 was consistent with the presence of negatively charged bromine-containing ions on such surfaces. The binding energies of all of the species detected on the surface (C, O, Br) shifted with the band bending, illustrating the importance of isolating the effects of band bending when measuring chemical shifts on semiconductor surfaces. The influence of band bending was confirmed by surface photovoltage (SPV) measurements, which showed that the core levels shifted toward their flat-band values upon illumination. Where applicable, the contribution from the X-ray source to the SPV was isolated and quantified. Work functions were measured by ultraviolet photoelectron spectroscopy (UPS), allowing for calculation of the sign and magnitude of the surface dipole in such systems. The values of the surface dipoles were in good agreement with previous measurements as well as with electronegativity considerations. The binding energies of the adventitious carbon signals were affected by band bending as well as by the surface dipole. A model of band bending in which charged surface states are located exterior to the surface dipole is consistent with the XPS and UPS behavior of the chemically functionalized Si(111) surfaces investigated herein.
ČEPIČKA, Josef. "Využití elektronek v současné době." Master's thesis, 2014. http://www.nusl.cz/ntk/nusl-170201.
Повний текст джерелаChung, Chao-Kai, and 鍾朝凱. "Using the Excitation Surface Plasma Waves of Optical Frustrated Total Internal Reflection to the Vacuum Measurement System." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/15257866893693515866.
Повний текст джерела清雲科技大學
電子工程研究所
94
The research is excitation of surface plasma wave (SPW) in thin metal film by the method of optical frustrated total internal reflection (OFTIR) to the vacuum. The research used Otto configuration and Kretschmann configuration to exciting surface plasma waves. In recent years, the vacuum is the technique to applied of widely in the industry. The vacuum purity is effect to the quality of a lot of developments of industry. Used vacuum pump is extract the air from the vacuum. The purpose is change surface plasma waves resonant angle , and examines purity of the vacuum. This technique to adopt dielectric constant of change achieve vacuum purity of measure. Because of gaseous components and density content is different in the air. When extract the vacuum , the dielectric constant will change the components and content .That change of the dielectric constant is precisely this measure technique of quality. The technology is different from vacuum measurement system. The new technology use surface plasma waves to measure purity in vacuum. This paper will be application computer to simulate.
FU, JUN-QING, and 傅浚清. "The Study of Contact and Wear Surface of Sliding Vane in Rotary Vacuum Pump By Ultrasonic Measurement." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/uatk5q.
Повний текст джерела國立高雄科技大學
模具工程系
107
This experiment was conducted to do research on the difference of wear down of putting pressure on abraded sliding vane in rotary vacuum pump, with non-contact measurement applied to this experiment, an ultrasonic measurement was used to scan the whole surface of contacted area. If there is no contact with the area, which detected by the wave sent from the ultrasonic detection equipment, the wave will reflect and absorb by the equipment receiver. If there exists contact, some waves will be transmitted to the sliding vane in rotary vacuum pump. Thus, the signal reflects to the detection equipment will weaken, therefore, we can realize the exposure degree from signal descending values, which comes from a fully scan of the ultrasonic detection equipment on the sliding vane in rotary vacuum pump. The experiment measured the variation between the contact area and the contact ratio of the difference pressure on sliding vane in rotary vacuum pump. As result indicated, the contact area of the sliding vane in rotary vacuum pump used by 5kg/cm2 will be within 480mm2 to 660mm2, and would be increased within 1200mm2 to 1800mm2 after putting more pressure one the contact area. As the contacted area of the sliding vane in rotary vacuum pump become more uneven, the abrasion become more obvious. Also, the different analytic data will be acquired by the observation of abrasion of the slideing vane in rotary vacuum pump by ultrasound and the difference of measuring contact area. The aforementioned data will determine that when the sliding vane need to be changed cost-effectively.
吳賢逸. "The modal analysis and measurement of the dry film lamination pre-cut device of a semiconductor wafer vacuum modeling machine." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/03033820436429912078.
Повний текст джерела國立彰化師範大學
機電工程學系
99
The objective of this study is to study the mode shape and natural frequency of the dry film lamination pre-cut device of a semiconductor wafer vacuum modeling machine. The Pro/E is employed to construct the 3D model and do the modal analysis. The simulation result is verified by modal test. The spectrum analyzer, three-axis accelerometer and percussion hammer are used to obtain the testing data. The result shows that the natural frequency obtained from finite element analysis and impact testing are coincident; they are: for the first four modes, 26.07Hz, 33.08Hz, 38.00Hz and 53.28. All the errors are within 5%. The results of this study should guide to better future designs of the equipment and are vital to reliable and safe operations of these devices.