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	Matrix Science - Help - Quadrupole Ion Trap MS
		A quadrupole ion trap is a sensitive and versatile mass spectrometer, roughly the size of a tennis ball [Paul, 1990,
		FTICR and quadrupole ion traps are unique in their ability to perform multiple stages of mass spectrometry, enormously increasing the amount of information obtainable from a molecule.
		The role of quadrupole ion traps is expanding from traditional pharmaceutical applications into the revolutionary field of proteomics, where identification of native and post-translationally modified proteins provides insight into complex biological systems [Haynes, 2000].
	www.matrixscience.com /help/ion_trap_main_help.html (1619 words)

	Quadrupole mass analyzer - Wikipedia, the free encyclopedia
		The quadrupole mass analyzer is one type of mass analyzer used in mass spectrometry.
		In a quadrupole mass spectrometer the quadrupole mass analyzer is the component of the instrument responsible for guiding sample ions to a detector, based on their mass/charge ratio (m/z).
		For example, the first quadrupole may be set to "filter" for a drug ion of a known mass, which is fragmented in the second quadrupole.
	en.wikipedia.org /wiki/Quadrupole_mass_analyzer (425 words)

	Quadrupole magnet - Wikipedia, the free encyclopedia
		Quadrupole magnets, sometimes called correctors, are designed to create a magnetic field whose magnitude grows linearly with the radial distance from its longitudinal axis, which is usually centered on and parallel to the main motion of the charged particles.
		In a quadrupole electromagnet there are four steel pole tips: two opposing magnetic north poles and two opposing magnetic south poles.
		The quadrupoles in the lattice are of two types: 'F quadrupoles' (which are horizontally focusing but vertically defocusing) and 'D quadrupoles' (which are vertically focusing but horizontally defocusing).
	en.wikipedia.org /wiki/Quadrupole_magnet (273 words)

	Encyclopedia: Quadrupole
		Image:Quadrupole magnet.gif A quadrupole is one of a sequence of configurations of electric charge or gravitational mass that can exist in ideal form, but it is usually just part of a multipole expansion of a more complex structure reflecting various orders of complexity.
		Quadrupole mass spectrometers consist of an ion source, ion optics to accelerate and focus the ions through an aperture into the quadrupole filter, the quadrupole filter itself with control voltage supplies, an exit aperture, an ion detector, detection electronics, and a high-vacuum system.
		A quadrupole consists of four parallel rods or poles throug which the ions being separated are passed.
	www.nationmaster.com /encyclopedia/Quadrupole (296 words)

	Ion Trap Mass Spectrometry
		A quadrupole ion trap is an instrument roughly the size of a tennis ball whose size is inversely proportional to its versatility.
		In this mode, analogous to the operation of a quadrupole mass filter, the amplitudes of rf and dc voltages applied to the ring electrode were ramped at a constant rf/dc ratio to allow stability, hence storage, of a single (increasing) m/z value in the ion trap.
		Ion Excitation and Ejection Ions oscillate with a frequency, known as the secular frequency, that is determined by the values for az and qz and by the frequency of the fundamental rf.
	www.abrf.org /ABRFNews/1996/September1996/sep96iontrap.html (4234 words)

	Quadrupole mass analyzer and method of operation in RF only mode to reduce background signal - Patent 6194717 (Site not responding. Last check: 2007-11-05)
		Then, the gas pressure provided in the first quadrupole or other multipole rod set can be such that the multiple of the pressure in the rod set times the length of the rod set is at least 4.times.10.sup.-2 torr-cm, preferably at least 10.sup.-1 torr-cm, and more preferably equal to or greater than 1.6.times.10.sup.-1 torr-cm.
		The fact that the phenomenon responsible for mass resolution of an RF-only quadrupole occurs at the exit of the device rather than throughout the length of the rod structure means that mechanical tolerances are significantly relaxed with respect to those of a conventional RF/DC quadrupole mass spectrometer.
		For conventional quadrupole operation, the chambers 36 and 47 are maintained at pressures of 7.times.10.sup.-3 torr and 2.times.10.sup.-5 torr respectively.
	www.freepatentsonline.com /6194717.html (4857 words)

	Detection of Bicycles at Demand-Actuated Traffic Signals
		A quadrupole loop is actually two loops wired in a figure-8 pattern side-by-side, in series with a single wire.
		A disadvantage of the conventional quadrupole loop design shown in Figure 3 is that it under marginal operating conditions (a low-conductance bicycle, a low-sensitivity setting, or a large loop footprint) it requires the bicycle wheels to be positioned in a precise location (over the center wire) for detection to occur reliably.
		Quadrupole footprints that are much longer can also be adjusted to detect bicycles, but result in progressively increased probability of spillover effects.
	www.humantransport.org /bicycledriving/library/signals/detection.htm (3381 words)

	Detection of Bicycles at Demand-Actuated Traffic Signals
		A quadrupole loop is actually two loops wired in a figure-8 pattern side-by-side, in series with a single wire.
		A disadvantage of the conventional quadrupole loop design shown in Figure 3 is that it under marginal operating conditions (a low-conductance bicycle, a low-sensitivity setting, or a large loop footprint) it requires the bicycle wheels to be positioned in a precise location (over the center wire) for detection to occur reliably.
		Quadrupole footprints that are much longer can also be adjusted to detect bicycles, but result in progressively increased probability of spillover effects.
	humantransport.org /bicycledriving/library/signals/detection.htm (3381 words)

	[No title] (Site not responding. Last check: 2007-11-05)
		Trapping ions in a given segment or quadrupole assembly allows time for ions which fall outside the stability window, established by the voltages applied to the poles or each segment or quadrupole assembly to be ejected from the quadrupole volume in the presence of ion to neutral gas collisions.
		Quadrupole assemblies 60,61 and 62 configured in multiple quadrupole assembly 8 are operated individually and jointly in both trapping and non trapping modes with DC acceleration fragmentation and resonant frequency excitation CID fragmentation and mass to charge selection with RF and +/-DC and resonant frequency ejection of unwanted ions.
		Typically, quadrupoles 60,61 and 62 of multiple quadrupole assembly 8 are operated to pass or trap ions with mass to charge values that are stable in the first stability region 102 as shown in Figure 12.
	www.wipo.int /cgi-pct/guest/getbykey5?KEY=99/62101.991202&ELEMENT_SET=DECL (16887 words)

	[No title] (Site not responding. Last check: 2007-11-05)
		The advantages in accordance with the invention, notably in respect of the possibilities of extension and the modular configuration of the circuit arrangement, are particularly advantageous in the case of an extension to a multichannel configuration.
		The quadrupole switching networks 6,7 are constructed each time as full bridges, the two terminals 10,11, 14,15 at the input 20,21 being connected each time to two IGB transistors 27 which are connected pair-wise a pole embracing fashion to two terminals 12,13, 16,17 at the output 22,23.
		The arrangement of quadrupole switching networks 6,6a, 7,7a and coils 1,2 in accordance with the invention is connected in parallel each time at the input 20,21 so as to be connected to four terminals 28,29, 30,31 of a particularly powerful and fast configuration 32 of voltage sources 4,4a in accordance with the invention.
	www.wipo.int /cgi-pct/guest/getbykey5?KEY=03/07011.030123&ELEMENT_SET=DECL (2813 words)

	Quadrupole Poster
		The quadrupole moment is zero in the center of the plasma and has equal and opposite values at the ends of the plasma.
		As shown below, the quadrupole moment at the plasma end is proportional to the length of the plasma.
		When the quadrupole fields are on, D is the sum of the diffusion due to the quadrupole field and the diffusion due to background processes.
	socrates.berkeley.edu /~fajans/Quadrupole/body.html (1472 words)

	5.4.3.6 Quadrupole Magnets (Site not responding. Last check: 2007-11-05)
		The quadrupoles determine the transverse focusing properties of the spectrometer and to a large extent its acceptance.
		All three quadrupoles for the HRS spectrometer are warm iron superconducting magnets.
		The operating current to the Q1 quadrupole coils is provided by Danfysik System 8000 power supplies, which can operate up to 3500 A current and 5 V voltage.
	hallaweb.jlab.org /document/OPMAN-old/node108.html (256 words)

	CHEMISTRY: ON NUCLEAR QUADRUPOLE RESONANCE
		Instead, NQR exploits the fact that some nuclei possess an electric quadrupole moment, which can be thought of as arising from two back-to-back electric dipoles (positive and negative charges separated by a short distance).
		That is, the only requirement for an electric quadrupole moment is that the nucleus be squashed (or stretched) along one axis.
		The intrinsic electric quadrupole moment of the nucleus and the electric-field gradient imposed from outside together create distinct energy states.
	scienceweek.com /2005/sb050128-5.htm (1248 words)

	Apparatus for and method of operating quadrupole mass spectrometers in the total pressure mode - Patent 4535236 (Site not responding. Last check: 2007-11-05)
		In all mass spectrometers, an ion source is used to generate an ion beam characteristic of the composition of the sample, and this ion beam is transmitted to an ion detector via a mass filter placed between the source and the detector.
		In the case of a quadrupole used as a residual gas analyser in an ultra high vacuum system, this mode of operation can be used to produce a measure of the total pressure in the system, eliminating the need for a separate pressure gauge, such as an ion gauge.
		Other uses for quadrupoles used in the RF only mode include high efficiency transmission devices used to transmit all ions of a particular range of m/e values, for example in mass spectrometers used for the study of ion-molecule reactions, etc., such as that described in U.S. Pat.
	www.freepatentsonline.com /4535236.html (3777 words)

	Quadrupole magnets were used in previous atomic clocks
		He has been having a hard time sourcing the quadrupole magnets, whereas it used to be much easier to find them.
		Well, it so happens that quadrupole magnets were used in atomic clock metrology in the past.
		This should not be construed as an explicit endorsement by him of that project, as he has not had the time to study it carefully.
	www.pureenergysystems.com /news/2004/06/28/6900027AtomicClockQuadrupoles (1041 words)

	Electric Quadrupole (Site not responding. Last check: 2007-11-05)
		Quadrupole and higher order multipoles are not important for the characteriztion of dielectric materials.
		Scott says that the macroscopic quadrupole effects are smaller than dipole effects by about the ratio of atomic dimensions to the distances of experimental observation.
		A linear electric quadrupole can be created by superimposing two electric dipoles of opposite orientation so that their positive charges overlap.
	hyperphysics.phy-astr.gsu.edu /hbase/electric/elequad.html (290 words)

	Quadrupole Magnets
		Quadrupole Magnets adds a new dimension to the growing selection of physics tutorial software from WhistleSoft, Inc. The program covers the fundamental properties of quadrupole magnets and explains how they are used in practical application.
		Quadrupole Magnets is divided into six sections: introduction, quadrupole singlets, matrix notation, quad systems, special topics, and related arrays and stability of beams.
		Integrate Quadrupole Magnets into your course as a part of a lab or assign the tutorial as a supplemental activity for independent study.
	webassign.net /pasnew/quadrupole_magnets/quadrupole_magnets.html (366 words)

	8.6 Monopole, Dipole and Quadrupole corrections
		Both corrections (quadrupole only for charged systems) will be calculated and added to the total energy if the IDIPOL flag is set.
		The corrections for the total energy are calculated as the energy difference between a monopole/dipole and quadrupole in the current supercell and the same dipole placed in a super cell with the corresponding lattice vector approaching infinity.
		This is due to the uncertainties in extracting the quadrupole moment of systems with excess electrons.
	cms.mpi.univie.ac.at /vasp/guide/node143.html (704 words)

	Fair Tax Blog
		The reason the FairTax is revenue neutral at the relatively low rate of 23% compared to the much higher rates in the current system is entirely because of the breadth of the tax base.
		One of the things that people frequently question about the FairTax is whether the 23% inclusive rate is sufficient to raise sufficient tax funds to leave the government with as much revenue as the current system is generating.
		When you speak of the impact of taxes you tend to talk about whether they are progressive or regressive.
	fairtaxblog.blogspot.com (3545 words)

	Simulation of a Unique Cylindrical Quadrupole Mass Analyzer Using SIMION 7.0.
		By segmenting the cross-section of the cylinder into eight or more pieces a quadrupole field can be produced that is equal to or superior to that generated by the standard rod based design.
		The ideal quadrupole fields would therefor be disrupted over a shorter distance near the interface.
		The first of these is the use of a split lens element and the second is a variation in the shape of the mass filter electrodes.
	www.sisweb.com /referenc/applnote/app-86.htm (1870 words)

	FDA/CFSAN Laboratory Information Bulletin Number 4084: Quadrupole Ion Storage Mass Spectrometry/Mass Spectrometry ...
		Quadrupole ion storage (ion trap) devices are the least expensive mass spectrometers on the market today.
		Mass spectrometer: A quadrupole ion storage (ion trap) instrument is required, utilizing 70 volts (nominal) electron energy in the electron impact (EI) ionization mode.
		Quadrupole rf modulation can solve this problem (secular frequency modulation), but requires long CID times to completely convert parent ion without excessive ion loss (100 to 150 ms).
	vm.cfsan.fda.gov /~ear/lib4084.html (6167 words)

	Quadrupole Moment of the Deuteron
		quadrupole moment as is observed for the deuteron.
		We should also note at this stage that it might appear that the quadrupole moment is a better observable from which to extract
		This is not true of the quadrupole moment that depends directly on both the S and D wave radial wavefunctions.
	www.phys.washington.edu /users/savage/Class_560/lec560_4/node5.html (148 words)

	[No title] (Site not responding. Last check: 2007-11-05)
		The acetylenic deuteron quadrupole coupling constant in 1-D-3,3 dimethyl-1-butyne is determined in neat liquid and in 20 mole percent solution in an inert solvent (C$\sb6$H$\sb{12}$), by combining NMR relaxation data with Raman line shape analysis of the totally symmetric A$\sb1$ mode at 1983 cm$\sp{-1}$.
		The value in the inert solvent was found to be 233 $\pm$ 4 KHz, which is significantly higher than the previously found value for the acetylenic deuteron in acetylene and nonyne, but is in excellent agreement with the ab initio calculation which was performed using "double zeta plus polarization" basis functions on smaller model molecules.
		A substantial lowering of the quadrupole coupling constant was observed in polar solvents.
	dbase.irandoc.ac.ir /00222/00222675.htm (310 words)

	Color display device having quadrupole convergence coils - US Patent 6411027 (Site not responding. Last check: 2007-11-05)
		The first unit 14 is positioned close to the gun and will be referred to as the "gun quadrupole", whereas the second unit 14' is located near the deflection unit and will be referred to as the "yoke quadrupole".
		The second convergence unit 14'("the yoke ring quadrupole") is obtained by making the coils 22' from electrically conductive wires, which are toroidally wound in a winding direction and according to a winding density distribution N (φ) given by
		A preferred method of manufacturing the second convergence unit 14' ("the yoke ring quadrupole"), where the coils 22' comprise layers, comprises the steps of: providing a ring-shaped element 21' and winding electrically conductive wire toroidally around the ring-shaped element 21'.
	www.patentstorm.us /patents/6411027.html (1902 words)

	Power Supply for Miniature Quadrupole Mass Spectrometer (Site not responding. Last check: 2007-11-05)
		A lightweight, low-power-consumption power supply has been developed to generate a combination of radio-frequency (RF) and dc voltages needed for the operation of a miniature quadrupole mass spectrometer that could operate unattended in the field for a long time, possibly using a battery as an energy source.
		More specifically, the circuit is designed to supply large, variable, frequency- and amplitude-stable RF voltages, variously floating or superimposed on positive or negative dc voltages, for application to primarily capacitive mass-spectrometer loads with capacitances of the order of 50 pF.
		These adjustments are inextricably coupled with the adjustment of the inductance of T1 to resonate with the capacitance of the affected portion of the quadrupole mass spectrometer.
	www.nasatech.com /Briefs/June00/NPO20493.html (736 words)

	Sourcing Quadrupole Magnets for Ion Source Beam Projector
		You will need to find two quadrupole doughnut or ring shaped Ferrite ceramic magnets measuring approximately 4 3/4" to 5" total diameter with a center hole measuring approximately 1 3/4" to 2" diameter.
		I was wondering if you might know some folks who may have an idea of where in the world I could find the quadrupole magnets specified in the ISBP instructions.
		Some of my contacts have suggested using four radial magnets of two different sizes that could fit together to essentially form a homemade quadrupole doughnut shape but so far everything we've been able to find would need to be machined in order to make them fit properly.
	www.pureenergysystems.com /os/IonSourceBeamProjector/sourcing/quadrupoles/index.html (427 words)

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