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Space Charge "Space charge" is charge in the dielectric, electrons, protons, and ions, that is moved around by the applied voltage. Space charge is a major factor in dielectric behavior, such as leakage, high-voltage reliability, and dissipation factor vs. frequency and vs. temperature. Space charge also explains why some capacitor reliability factors, such as breakdown voltage and corona starting voltage, tend to correlate with the peak-to-peak applied voltage better than with the peak applied voltage. my.execpc.com /~endlr/space_charge.html   (679 words)

Space charge - Wikipedia, the free encyclopedia This is called space charge effect, and it determines the current-voltage characteristic of tube. Space charge is an inherent property of all vacuum tubes. Space charges can also occur within solid or liquid dielectrics that are stressed by high electric fields. en.wikipedia.org /wiki/Space_charge   (752 words)

Space Charge And Photons (Book Review)   (Site not responding. Last check: 2007-10-18) The energy lost is shown to be reasonably close to the measured low-frequency microwave radiation which appears to penetrate all space. The end result is consistent with observed experimental evidence; can be shrunk to approach the concept of a point charge; fits much of the data of the neutrino; appears consistent with an earlier proposed string model of hadron structures and leads to further development. Further, it is shown that the lost energy appears to closely match the observed microwave energy in space. www.padrak.com /ine/NEN_6_10_13.html   (511 words)

Space-charge calculations: The space through which the beam passes is notionally divided into an array of square or cubic cells, each of which can hold a space-charge. The space-charge cells are completely independent of the ray mesh spacing used for the ray mesh points (if rays are traced by the mesh method), and so the mesh spacing of the space-charge cells does not have to have the same as the mesh spacing for the rays. The presence of the space-charges of the rays causes changes to the charges on the boundary elements (ie the electrodes and their segments), which are therefore re-calculated at each iteration. www.electronoptics.com /Space.htm   (477 words)

AMS Glossary In atmospheric electricity, space charge refers to a preponderance of either negative or positive ions within any given portion of the atmosphere. A net positive space charge is found in fair weather at all altitudes in the atmosphere and is largest near the earth's surface. The general downward flux of this positive space charge is known as the air–earth conduction current. amsglossary.allenpress.com /glossary/search?id=space-charge1   (119 words)

Field effect devices formed from porous semiconductor materials - Patent 5359214 When voltage is applied to the internal pn-junctions, the space charge around the pores widens or contracts, depending upon the direction of the bias, thereby permitting the modulation of current flow through the channel. A device according to claim 9, wherein said porous region defines a plurality of space charge regions circumscribing each internal pn-junction, wherein the thickness of each space charge region is adapted to vary upon the application of a voltage bias between said source and drain. Because of the importance of the spacing between the space charge layers in defining the effective length of the channel, it should be understood that the pore diameters, interpose spacings, and channel resistivity will depend on what type of transistor is being fabricated. www.freepatentsonline.com /5359214.html   (3684 words)

The Joe Cell - Abundant, free, clean energy through space charge physics Static electricity is an electrical charge caused by an imbalance of electrons on the surface of a material. The charge that is transferred during contact electrification is stored on the surface of each object. Space charge engine technology may just be our future. www.thejoecell.com   (3434 words)

Space Charge To safely generate electrical power in space, designers of the ISS had to keep in mind that low-Earth orbit is filled with a charged plasma. In the GEO space environment, the major interaction of concern is differential charging of various parts of a spacecraft, leading to high electric fields and arcing between spacecraft components. The grounding of the space station's photovoltaic arrays (the negative end of the arrays are grounded to the structure) place the ISS at large negative electrical potentials (-160 volts DC) relative to the ambient space plasma when the arrays are producing power. science.nasa.gov /headlines/y2001/ast13nov_1sidebar.htm   (1141 words)

Method for controlling space charge-driven ion instabilities in electron impact ion sources patent invention In a method for inhibiting space charge-related effects in an ion source, an electron beam is directed into a chamber to produce ions from sample material in the chamber. A voltage pulse is applied to the chamber to perturb an electron space charge present in the chamber. Typically, a mass spectrum is a series of peaks indicative of the relative abundances of charged components as a function of mass-to-charge ratio. www.freshpatents.com /Method-for-controlling-space-charge-driven-ion-instabilities-in-electron-impact-ion-sources-dt20061026ptan20060237641.php   (2308 words)

[No title]   (Site not responding. Last check: 2007-10-18) The space charge field of the positive ions is held responsible for the reduction of the ionization of the advancing electrons and is comparable to the applied field ; we are thus entering the streamer regime. From this, the charge multiplication factor was evaluated as : a(n) = oc (1 - BlnnjN) (1) x rrjv = 1 J l___ - I ln(l - B lnn/JV) - 11 (2) in which NT = exp(orc#). From previous work2 it has been surmized that for normal hydrocarbons, little space charge distortion occurs until n^ N = 107, and from Richter's data1 an equally good fit to www.nature.com /nature/journal/v188/n4752/ris/188734a0refs.ris   (588 words)

Space Charge   (Site not responding. Last check: 2007-10-18) Gaseous Detectors, Operational Modes), the charge density in the electron-ion avalanche is small compared to the charge density on the wire, and only small signal distortions occur. For chambers exposed to high-intensity beams, they may accumulate, and then produce space charge effects, in particular distortions of the effective electric field, causing inefficiencies of the chamber and thus influencing acceptance and calibration parameters of the chamber (e.g. Compare the space charge in wire chambers with the space charge region in a semiconductor detector, which is, in fact, the active region (the depleted volume). rkb.home.cern.ch /rkb/PH14pp/node174.html   (156 words)

Designing a High Power FEL Driver All are based on the use of a 10 MeV injector, to limit the impact of space charge during beam formation and handling at the low energy end of the machine. We have therefore selected option e; this choice minimizes the impact of CSR and space charge on the FEL drive beam, at the cost of increased complexity in the energy recovery transport. PARMELA studies indicate space charge is important only at low energy; in the parameter regime of interest it may be neglected at 40 MeV. www.jlab.org /%7Edouglas/FEL/guide/application.html   (1176 words)

ARS | Publication request: An Electrostatic Space Charge System to Control Bacteria and Spores on Surfaces In our preliminary work, a small chamber with an electrostatic space charge system (ESCS) was used to transfer a strong negative charge to bacteria on stainless steel coupons. Ion density was varied by adjustment of the ionizer power supply voltage and/or moving the ground plane closer or further from the electrode points to achieve ion densities from 103 to 106 negative ions/cm2. These data indicate that the ESCS could have an impact on the microbial load in a facility by direct killing of bacteria and spores on surfaces. www.ars.usda.gov /research/publications/publications.htm?SEQ_NO_115=140130   (252 words)

Experimental Determination of the Dynamics of Space Charge Develpment in Insulators This so-called "space charge" is important as it distorts the electrical field and may precipitate electrical breakdown. Theories of space charge kinetics have been developed during this century but direct measurements have not been possible until recently. This programme developed equipment for measuring space charge by electrically monitoring its displacement as an acoustic pulse travels through the insulation. www.le.ac.uk /engineering/research/groups/power/highvolt/DC_SC/DC_SC.html   (231 words)

Space Charge Tubes: Tube Projects Without Lethal Voltage! These tubes worked on something called the "space charge" principle, which basically used the first grid after the cathode to accelerate electrons toward the weakly-charged plate, which was now working at 12V instead of 180V. This page is a compendium of what I know about space charge tubes, as well as any Web links or citations in paper literature about them. Another space charge circuit using a type 49 operating at 7.5 volts, with a second type 49 as an audio amp. www.duntemann.com /12vtubes/12vtubesindex.htm   (4039 words)

TheHostPros.com - hi performance low cost web site hosting from $2.90/mo - cheap extras, free setup and free trial - ... Once your free weeks are over, your account will be charged for the services you actually use, each week, for as long as you continue with us. To calculate the weekly hosting charge for each site, we take the total of all the charges for that week (see chart at right) and then deduct a percentage, depending on how large your total is, that week. If your site is somewhat heavy on disk space but very light on traffic, you might still pay only the minimum 67 cents a week (or just a little more). thehostpros.com   (1401 words)

[No title] The spatially non-uniform optical intensity distribution causes the diffusion of photo-generated free charge carriers and results in the formation of an internal space charge electric field in the equilibrium. When the center frequencies of the laser beams are not equal, the internal space charge field is set in motion and drifts free charge carriers out of the semiconductor devices, resulting in measurable photocurrents which contain information regarding the relative magnitudes of the laser oscillating frequencies. This talk presents a brief introduction of the moving space charge field effects in various semiconductor devices/structures and their applications in the fields of laser Doppler velocimetry, vibrometry, and spectroscopy. www.osa.org /membership/shareddocuments/travelinglecturer/speakers/speakers/wang.aspx   (205 words)

Dr Mingli Fu Space Charge Accumulation Under Electrical Field and its Application in XLPE Ageing Assessment Fu and G. Chen, “Space charge measurement in polymer insulated power cables using flat ground electrode PEA system”, IEE Proc. Fu and G. Chen, “Space charge measurement in XLPE cables with temperature gradient through the insulation”, Ann. www.le.ac.uk /engineering/research/groups/power/staff/fu.html   (1032 words)

President Bush decides he's in charge of space This means that if anyone he doesn't like tries to go there, he'll tell them not to. "This policy emphasises that the United States is committed to peaceful uses of space by all nations and that space systems enjoy the right of free passage," a White House spokesman said. "Protection of space assets does not imply some sort of forceful action," he added. www.theinquirer.net /default.aspx?article=35213   (156 words)

mikemullican's Home — Welcome to Chemweb From an electrical point of view, a grain boundary consists of a grain-boundary core and two adjacent space-charge layers. The grain-boundary cores of acceptor-doped zirconia and ceria are positively charged, probably owing to the oxygen vacancy enrichment there. Oxygen vacancies are therefore depleted in the space-charge layer. www.chemweb.com /Members/mikemullican/journals?type=issue&jid=00796425&iid=00510002   (501 words)

Definition of space charge - Merriam-Webster Online Dictionary : an electric charge distributed throughout a three-dimensional region Learn more about "space charge" and related topics at Britannica.com Find more about "space charge" instantly with Live Search www.webster.com /dictionary/space+charge   (36 words)

Mini Workshop on Linac Space Charge Wei: HEBT/Ring Limitations to Linac Emittance & Halo Hofmann: Overview on Resonant Space Charge Effects in Linacs Jeon: Parmila studies of emittance transfer and mismatch for SNS www.sns.gov /APGroup/workshops/linacSC_6_01/linacSC_6_01.htm   (168 words)

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