Abstract: A cooking device containing a housing with a cooking chamber and a door to close off the cooking chamber and at least one control and display panel with an optical luminous display. The control and display panel can display the different operation modes of the cooking chamber and the on and/or off modes of the cooking chamber.

Abstract: An electrical resistance heating element has an axially elongated flat carbon fiber tow, which includes a multiplicity of continuous axially parallel carbon filaments. The tow is sandwiched between two layers of polyester sheet material and bonded to only one of the layers. The other of the layers overlies the tow in direct contacting engagement with and unconnected relation to the tow and is connected to longitudinally extending marginal portions of the one layer along transversely opposite sides of the tow. The heating element may be produced by a continuous forming process.

Abstract: A defrost vessel for a microwave oven includes a body having a certain space therein for receiving a refrigerating load, and an antenna connected to the body for oscillating a microwave into the space of the body. When microwave is supplied into a cavity of the microwave oven, the microwave is oscillated into the space of the body by the antenna and thus the microwave is deeply penetrated up to inside of the refrigerating load. Also, the microwave is secondly emitted into the space of the body from an edge of the slot, thereby completely defrosting the refrigerating load.

Abstract: A disposable utensil for cooking, warming, and heating articles. More particularly, in the preferred mode, the invention is a disposable utensil which comprises a liner surrounding a permeable armature, which comprises a plurality of vertical members configured in a predetermined framework. The armature functions to elevate an article such as any type of food, in such a manner as to prevent the article from becoming soggy from contact with effluent drippings produced during the cooking, warming, or heating process. The invention may also utilize an optional support element for heavier or larger articles, as well as an optional layer of absorbent material, such as ovenproof paper, felt, wadding or fibrous material for enhanced absorption of effluent drippings. The utensil is suitable for usage in connection with cooking appliances of all types and all sizes.

Abstract: The invention is based on an apparatus and a method for scanning specimens (1) using an optical imaging system (3) and a scanning stage (2), images of the specimen (1) being acquired by means of a camera (4), and/or measurements on the specimen (1) being made by means of an optical measurement device (5), at specimen points Xp, Yp. For that purpose, the scanning stage (2) is calibrated by obtaining and storing height values Z at different calibration positions X, Y of the scanning stage (2), and thereby generating a running height profile of the scanning stage (2). For the scanning of specimens (1), the specimen height positions Zp at specimen points Xp, Yp are determined by means of a reference height Zref of the specimen (1) together with the running height profile of the scanning stage (2).

Abstract: An optical path coupling member aligns an optical axis directed to a light condensing member of the first wavelength light having a shortest wavelength with that of the third wavelength light having a longest wavelength. A diffraction element condenses +2nd order diffracted light of the first wavelength light and +1st order diffracted light of the second wavelength light and third wavelength light into a first photodetector, the ?2nd order diffracted light of the first wavelength light and ?1st order diffracted light of the third wavelength light into a second photodetector, and ?1st order diffracted light of the remaining second wavelength light into a photodetector, using ±2nd order diffracted light of the first wavelength light and ±1st order diffracted light of the second wavelength light and third wavelength light as signal light from an optical information recording medium. Consequently, the overall size of the optical pickup apparatus is reduced.

Abstract: A system for measurement of the height, angle and their variations of the surface of an object comprises a measurement module and an astigmatic optical path mechanism. The optical path mechanism makes a laser beam pass a lens assembly and focus on an object. The reflected light passes the lens assembly and an astigmatic lens, arriving at the photo sensor assembly, forming a light spot thereon. The translational displacements of the object are measured by the variations in shape of the light spot on the photo sensors. The angular displacements of the object are measured accordingly by the movement of the light spot on the photo sensors.

Abstract: A semiconductor pickup device includes a pixel circuit including: a photodiode passing to a prescribed node a current of a value corresponding to intensity of light received; a log transistor operating in a log region when the prescribed node is increased in potential; and a reset transistor operative for the prescribed node's potential higher than a threshold potential to reset in response to a reset signal the prescribed node's potential to a reset potential, and operative for the prescribed node's potential lower than the threshold potential to avoid the resetting. For low illuminance the pixel circuit decreases in frame rate and lower minimum illuminance required for pickup can be provided.

Abstract: A digital camera includes an image sensor having an array of CCD (Charge-Coupled Device) cells on which an optical image is focused via a lens and a shutter. The image sensor produces an image signal by photoelectric conversion. The image signal is clamped by an analog front end circuit, which feeds a processed analog signal to an analog-to-digital converter. The resultant digital signal is input to a signal processor. The analog front end circuit switches horizontal scanning lines to be clamped in accordance with image pickup information. The horizontal scanning lines to be clamped lie in an optical black area where a photodiode is included in each CCD cell or an optical black area where the former is not included in the latter.

Abstract: An output amplifier for a solid-state imaging device is provided and includes: a floating diffusion that stores a signal charge; and at least three source follower circuits that output a signal in accordance with a change of a potential on the floating diffusion, the at least three source follower circuits being sequentially connected in decreasing order of drain voltage from a first circuit of the at least three source follower circuits to a last circuit of the at least three source follower circuits.

Abstract: Improved column sample-and-hold (CSH) circuitry particularly useful in a CMOS imager is disclosed. In the improved circuitry layout, the overall column height of the CSH circuitry is reduced by providing a plurality of pairs of sampling and reference capacitors in a vertical stack over the columns that the capacitors service. The number of pairs provided in the vertical stack is subject to optimization, and for a given set of design constraints, a certain form factors can prove to be optimal. No modification needs to be made to the pixel array (such as pixel pitch), and the sensing circuitry otherwise requires no electrical or process modifications as the values for the capacitances as well as other design constraint are preserved. However, the vertical stacking of the plurality of pairs of capacitors reduces the overall column height (CH), which conserves layout space on the CMOS imager integrated circuit.

Abstract: A signal processor and processing method are provided for measuring current received from a photo-detector. Generally, the processor includes a transimpedance amplifier (TIA) to integrate a current received from a photo-detector in the optical navigation system to generate a voltage signal having a slope that is proportional to the received current, and a comparator having a first input coupled to an output of the TIA to receive the voltage signal, and a second, inverting, input coupled to a threshold voltage. The comparator is configured to compare the voltage signal to the threshold voltage and to generate an output pulse having a predetermined voltage and a duration or width that is a function of the received current.

Abstract: An apparatus for checking the integrity of tools includes an optoelectronic system (7) with a laser beam (21), a base (6) movable along a longitudinal direction (X) for enabling displacements between tool and optoelectronic system and a device for checking the mutual position including, for example, a transducer (9,10). A sensor (22) of the optoelectronic system detects the interruption of the beam and, on the basis of the transducer signal at said interruption and on the comparison with a known value, the integrity of the tool is determined. A coupling mechanism (24) of the optoelectronic system coupled at the base enables oscillations of the former along a transversal reference surface, that define a sensitive delimited area (33). The oscillations are controlled by means of a motor (26) and interruptions of the beam are detected and signalled by the sensor the moment that the end of the tool interferes with the sensitive delimited area.

Abstract: An object of the present invention is to enable the detection of the presence/absence of an object over a plurality of detection areas without using a plurality of light-receiving devices and light-emitting devices. A sensor detects the presence/absence of an object in a detection area where a light-emitting area of a light-emitting device and a light-receiving area of a light-receiving device are overlapped with each other, and includes: a power supply unit that outputs a driving current I of the light-emitting device such that its current value is variable; a control unit that has the function of controlling the power supply unit to change in magnitude of the driving current I of the light-emitting device, and determining the presence/absence of an object based on an output from the light-receiving device to output the result of determination as a detection signal; and an output signal 50 that converts the detection signal into an analog signal to output the converted signal as a signal ?.

Abstract: An optical navigation sensor receives light that is produced by a light source and reflected from a surface. The optical navigation sensor has a silicon substrate having a plurality of photo-sensing regions, each of which receives a portion of the reflected light, and each of which provides a pixel of navigation information. At least one layer of material is deposited on the photo-sensing regions of the silicon substrate during a silicon wafer fabrication process. Each layer has a thickness that causes it to serve as an anti-reflection coating and reduce a percentage of light that is reflected away from the photo-sensing regions of the silicon substrate. A circuit biases each of the photo-sensing regions with a current, the current providing a given responsivity, and the current being less than a current that would be required to provide the given responsivity absent the at least one layer of material.

Abstract: An imager captures successive images of an object. One image is then subtracted from another image to generate difference images. Each difference image is then correlated with itself or with one of the images used to generate the difference image to determine the relative motion between the imager an the object.

Abstract: A soil moisture sensor uses a non-collimated light source and a photosensor, respectively, mounted at the foci of a transparent ellipsoidal plastic body. The dimensions of the body are such that emitted light rays are internally reflected toward the photosensor at the surface of the ellipsoid if the surface is dry, but refracted outwardly of the body when the surface is wet. The amount of light reflected onto the photosensor is thus a measure of the amount of moisture at the surface of the sensor. Direct illumination of the photosensor by the light source is prevented either by interposing opaque electronic components between them on a circuit board, or by taking advantage of light source characteristics to minimize the amount of transmitted light. If a circuit board is used, it is completely encapsulated against moisture penetration by fixing it in a carrier and molding the body around and onto the carrier to form a monolithic unit with the carrier and circuit board.

Abstract: An image processing system includes a lamp which emits light to a glass, an imaging device which captures light which is emitted from the lamp and reflected by the glass, and an optical filter, located between the glass and the imaging device, which transmits rays with a specific wavelength of the reflected light. A lens is provided in front of the imaging device, and a focus of the lens is adjusted to a point beyond the glass, and an image processor is provided which processes an image captured by the imaging device and detects moisture on the glass.

Abstract: An encoder that can detect the presence of noise occurring within the encoder. The encoder is constructed by incorporating within the same apparatus: a movement detecting unit for detecting the movement of a moving body; a signal processing circuit for processing a movement detection signal supplied from the movement detecting unit, and thereby producing an encoder signal representing the position and/or the amount of displacement of the moving body; and a noise detecting unit for detecting noise superimposed on the movement detection signal. According to this encoder, a noise voltage generated within the encoder via a stray capacitance is detected within the encoder and is output as noise data, so that the noise level can be detected without requiring the use of an external measuring device. Further, by outputting encoder data and noise data occurring at the same instant in time, the reliability of the encoder data can be judged based on the condition of the noise level.

Abstract: A printer includes laser beam detecting sensors for detecting a laser beams at two positions in the main scanning direction. Write clock generating circuits measure a number of counts of a predetermined clock during a period since one of the laser beam detecting sensors detects each of the beams until another sensor detects the beam. A write clock frequency adjusting circuit takes the number of counts for one laser beam as a reference value and adjusts write clock frequencies of other laser beams so as to coincide with the reference value.

Abstract: Provided is a light scanning apparatus, including a light source, a light source controller to control an on/off operation of the light source, a light deflector deflecting light emitted from the light source, an image formation optical system to direct light deflected by the light deflector on a scan area of a to-be-scanned surface, a synchronous signal detector to receive the light emitted from the light source and to detect a synchronous signal for light scanning, and a light path changer changing a path of light emitted from the light source and incident upon the light deflector.

Abstract: Methods and systems for operating an apertureless microscope for observing one or more features to a molecular sensitivity on objects are described. More particularly, the method includes moving a tip of a probe coupled to a cantilever in a vicinity of a feature of a sample, which emits one or more photons at a detected rate relative to a background rate of the sample based upon the presence of the tip of the probe in the vicinity of the feature. The method modifies the detected rate of the feature of the sample, whereupon the modifying of the detected rate causes the feature of the sample to enhance relative to background rate of the feature.

Abstract: An apparatus and method measures the gap between one substantially planar object, such as a mask, and a second planar object, such as a substrate. A gapping mark is used for measuring a gap between the first and second plates. The gapping mark includes a first grating on a first surface of a first plate, the first grating having a first uniform period in a first direction. A second grating is located on the first surface of the first plate, the second grating being adjacent to the first grating in the first direction, the second grating having a second uniform period in the first direction. The gapping mark also includes a third grating on the first surface of the first plate, the third grating being adjacent to the first grating in a second direction, the second direction being substantially orthogonal to the first direction, the third grating having the second uniform period in the first direction.

Abstract: A system for providing the timing alignment for a scanner. The system includes a removable source and detector assembly which is placed near the center of the scanner when in use. The source includes a long-lived positron emitting radioactive source. The radioactive source is in close contact with a fast plastic scintillator or other mechanism of detecting the ionization due to positron decay. A method for reading out the precise time at which the surrounding medium detects the ionization due to positron decay. A mechanism for using this time as a reference clock unto which the detectors in the scanner can be aligned.

Abstract: A method for cluster fragmentation comprises the production of at least one cluster which contains a carrier substance and the fragmentation of the cluster into cluster fragments, with the cluster being loaded before the fragmentation with at least one reaction partner and the reaction partner being part of at least one cluster fragment after the fragmentation. A cluster beam system for performing the method, and applications of the cluster fragmentation for analysis and purification of surfaces, for analysis of clusters, and for the operation of ion thrusters are also described.

Abstract: The invention provides apparatus and methods for performing time-of-flight (TOF) mass spectrometry. A TOF mass spectrometer of the present invention comprises one or more ion focusing electric sectors. At least one of the electric sectors is associated with an ion optical element. The ion optical elements comprise at least one adjustable electrode, such that the adjustable electrode is able to modify the potential experienced by an ion entering or exiting the electric sector with which it is associated.

Abstract: A mass spectrometer comprises an ion source which provides a beam of ions; a mass filter comprising a pair of electrodes and a drive circuit, the drive circuit operable to apply a time varying voltage to the electrodes having a profile that accelerates the ions to equal velocities irrespective of their mass: charge ratios; and an ion detector for detecting the proportions of ions according to their mass-to-charge ratios. In one embodiment, the voltage profile is exponential. In another embodiment, the voltage profile is a sequence of constant amplitude and increasing repetition frequency pulses. The novel mass filter thus imparts equal velocities to all ion species irrespective of their mass. This allows the ion species to be discriminated at the detector by energy, enabling simple and compact detection schemes to be used.

Abstract: The present invention provides an electron beam apparatus for evaluating a sample surface, which has a primary electro-optical system for irradiating a sample with a primary electron beam, a detecting system, and a secondary electro-optical system for directing secondary electron beams emitted from the sample surface by the irradiation of the primary electron beam to the detecting system.

Abstract: One embodiment disclosed relates to a method for automated focusing of an electron image. An EF cut-off voltage is determined. In compensation for a change in the EF cut-off voltage, a focusing condition is adjusted. Adjusting the focusing condition may comprise, for example, adjusting a wafer bias voltage in correspondence to the change in cut-off voltage. Another embodiment disclosed relates to a method for automated focusing of an electron image in a scanning electron imaging apparatus. A focusing condition of a primary electron beam in a first image plane is varied so as to maximize an intensity of a secondary electron beam through an aperture in a second image plane.

Abstract: An infrared imager for detecting infrared (IR) radiation of a scene in a field of view (FOV) of an optical system and converting the IR into a visible image wherein the imager consists of an array of uncooled microbolometers in a focal plane of the optical system and a array of light emitting diode (LED) or liquid crystal display (LCD) elements. The IR radiation collected by the microbolometer produces a change in an electrical output applied to electronic circuitry connected to the array of LEDs or LCDs. The electronic circuitry controls the intensity of a LED element or the reflectance of an LCD element. As a result, the imager converts the infrared radiation from the scene into visible light. The light reflected from the LCD or produced by LEDs in an array constitutes the scene image.

Abstract: An optical lens 1 makes three components of visible light and near infrared light in different wavelength regions severally form images at different locations according to their wavelengths. An imaging element 2 has a plurality of pixels, which include pixels having a visible light detection section 6 and pixels having a near infrared light detection section 8. The visible light detection section 6 has three detectors 3, 4, and 5 which detect three components of visible light which form images at locations of different depths in the same pixel according to their wavelengths. The near infrared light detection section 8 has a near infrared light detector 7 which detects near infrared light which forms an image at a location of a depth different from the depths at which the three components of visible light form images.

Abstract: A sensor system according to various aspects of the present invention comprises a sensor viewing an area via an optical path and a strut at least partially interposed across the viewing area. The strut is configured to taper along the optical path towards the sensor. In an exemplary embodiment, the strut includes at least two sides forming an angle along their common edge exposed to the sensor along the optical path.

Abstract: An instrumentation package in broad terms includes at least one substantially cylindrical instrumentation component; a substantially cylindrical shield surrounding the instrumentation component, the shield having a diameter less than a standard predetermined diameter; and a sizing sleeve around the shield, thereby increasing the diameter of the sleeve to the standard predetermined diameter. A nuclear detector package is also disclosed that includes a substantially cylindrical crystal element; a photomultiplier tube arranged coaxially with the crystal element; an optical coupler sandwiched between one end of the crystal element and an adjacent end of the photomultiplier tube; the crystal element, optical coupler and photomultiplier tube hermetically sealed within a cylindrical shield; and a flexible support sleeve extending exteriorly along the crystal element and the photomultiplier tube and radially inside the cylindrical shield.

Abstract: A limiting device (9) for electromagnetic radiation (3; 5; 7) includes an essentially flat beam cross-section limiter (10) which partly or completely encloses at least one passage aperture (12; 13) for beams (5; 7) and is constructed so that it also includes at least one second beam cross-section limiter (14) which, in the active position, constitutes at least one longitudinal component extending at an angle to the first beam cross-section limiter (10).

Abstract: A portable nuclear material detector generally includes a scintillating fiber radiation sensor, a light detector, a conditioning circuit, a frequency shift keying (FSK) circuit, a fast Fourier transform (FFT) circuit, an electronic controller, an amplitude spectral addition circuit, and an output device. A high voltage direct current (HVDC) source is provided to excite the light detector, while a separate power supply may be provided to power the remaining components. Portability is facilitated by locating the components of the detector within a handheld-sized housing. When bombarded by gamma particles, the radiation sensor emits light, which is detected by the light detector and converted into electrical signals. These electrical signals are then conditioned and converted to spectral lines.

Abstract: The present invention is directed to an integrated scintillator and collimator array for a CT detector. The integrated scintillator and collimator are fabricated from a manufacturing process or technique whereupon an array of scintillator material is positioned on a tooling base such that a collimator mold housing having a collimator mold therein may be positioned on the block of scintillator material. The block and mold housing are then aligned allowing a collimator mixture to be disposed into the mold. The collimator mixture is then allowed to cure to form an integrated scintillator and collimator.

Abstract: This invention relates to an apparatus for detecting hydrogeneous material on a ship's deck comprising a neutron source located below the surface of the ship's deck and emitting fast/energy-rich neutrons, and a detector device that is located below the surface of the ship's deck and detecting thermal neutrons. The invention further relates to a corresponding method of detecting hydrogeneous material on a ship's deck. Hereby an apparatus and a method are provided for detecting occurrences of water on a ship's deck, wherein these occurrences appear in particular when travelling in rough weather conditions. The apparatus being located below the ship's deck, it is consequently not exposed to wear due to rough weather conditions.

Abstract: A radiographic image is obtained by combining at least two radiographic sub-images acquired by at least an upper and lower 2-dimensional radiation sensor having sensor pixels. The radiation sensitive area of the lower sensor is overlapped by the upper sensor. Overlap is preferably at least two pixel rows, but can also be limited to non-imaging parts of the upper sensor. The radiation sensors may comprise a radiation to light converting layer. Preferably the sensors are built using CMOS technology, exhibiting less radiation absorption outside the radiation sensitive area.

Abstract: Systems, methods and apparatus are provided through which in some embodiments a reference display receives reference information and displays the reference information from a digital image detector, wherein the reference display is in close proximity to the digital image detector.

Abstract: A radiation detection module and radiological imaging apparatus capable of improving spatial resolution. A semiconductor radiation detector includes a plurality of semiconductor radiation detector elements and conductive members which are copper plates. A detector element provides an anode electrode on one of facing sides of a semiconductor region and a cathode electrode on the other side. The respective detector elements are arranged in parallel in such a way that the cathode electrodes and anode electrodes face each other respectively, and the anode electrodes are electrically connected together and the cathode electrodes are electrically connected together via the conductive members respectively.

Abstract: A two dimensional image production method by using a solid-state image sensing device, wherein the solid-state sensing device comprises a picture element producing part where electric charges generated by way of photo-electric conversion when receiving exposure is stored as charge signals, and a dark current measuring part where a dark current is stored without receiving exposure. The method comprising the steps of: preparing and storing in advance the output ratio data for a fixed exposure time between dark current component of each pixel element or each pixel element column in the picture element producing part and that of a specified pixel element or a specified pixel element column in the dark current measuring part, and producing sequentially pixel datum removed a dark current component while performing radiography, by executing a predetermined arithmetic operation for the signals of the electric charges outputted from the picture element producing part depending on the output ratio data.

Abstract: The afterglow and count rate/dead time of a nuclear imaging detector are calculated for use in correcting event detection and energy integration circuits. Energy value signals and event triggering signals are respectively integrated as a function of the decay setting of the detector, until they reach stable values, which are respectively used as afterglow and count rate/dead time signals used by a data processor of the detector.

Abstract: An apparatus and a method are disclosed for rapidly controlling the rate of ion generation in an ion source. The ion source includes an ion chamber, filament-cathode, a mirror electrode, and a grid. The ion source is operable to generate an ion beam from the ionization of ion precursor gas present in the ion chamber by electrons emitted from the filament. The rate of ion generation is controlled by modifying the potential of the grid relative to the filament to control the number of electrons available for ionization between the grid and the mirror electrode. An alternative embodiment for rapidly controlling the rate of ion generation in an ion source is also disclosed.

Abstract: A sample measuring method and a charged particle beam apparatus are provided which remove contaminants, that have adhered to a sample in a sample chamber of an electron microscope, to eliminate adverse effects on the subsequent manufacturing processes. To achieve this objective, after the sample measurement or inspection is made by using a charged particle beam, contaminants on the sample are removed before the next semiconductor manufacturing process. This allows the contaminants adhering to the sample in the sample chamber to be removed and therefore failures or defects that may occur in a semiconductor fabrication process following the measurement and inspection can be minimized.

Abstract: A comprehensive system and method of rendering the mail safe for handling and for detecting and containing suspect pieces and which can be fitted or retrofitted into mail and package processing facilities with relative ease. The system of the present invention includes a mail tray initial neutralizing sub-system, a subsequent neutralizing sub-system, an analyzing (potentially hazardous material detection) sub-system, a diverting mechanism, and a receiving and holding sub-system (secure out-sort pocket). All components can be controlled or operate in conjunction with a processing/computing sub-system. A feeder sub-system provides the mail from trays, after initial neutralization by the initial neutralizing sub-system, to the mail transport system.

Abstract: A contamination barrier that passes through radiation from a radiation source and captures debris coming from the radiation source is disclosed. The contamination barrier includes an inner ring, an outer ring, and a plurality of lamellas. The lamellas extend in a radial direction from a main axis, and each of the lamellas is positioned in a respective plane that include the main axis. At least one outer end of each of the lamellas is slidably connected to at least one of the inner and outer ring.

Abstract: An ion implanter includes a sample stage for setting a sample having a main surface, an ion generating section configured to generate a plurality of ions, the ion generating section including a container into which an ion source gas is introduced and a filament for emitting thermal electrons provided in the container, an implanting section configured to implants an ion beam containing the plurality of ions in the main surface of the sample, and a control section configured to control a position of the sample or a spatial distribution of electrons emitted from the filament so that a direction of eccentricity of a center of gravity of the ion beam coincides with a direction of a normal line of the main surface.

Abstract: An exposure method for projecting a pattern formed on a reflection plate onto a substrate, via a projection optical system, using extreme ultraviolet light. The method includes a detection step of detecting a relative position between a second mark formed on a plate holding unit for holding the reflection plate and a third mark formed on the reflection plate. The detection step includes sub-steps of (i) detecting light reflected from the second mark with a detector, (ii) detecting light reflected from the third mark with the detector, and (iii) changing a relative position between the plate holding unit and the detector between sub-steps (i) and (ii).

Abstract: A particle therapy system capable of measuring energy of a charged particle beam even during irradiation of the charged particle beam is provided. A beam delivery (irradiation) system comprises a block collimator constituted by a pair of collimator members, and an energy detector mounted to one of the collimator members to be disposed on the upstream side thereof. When the pair of collimator members are moved in directions away from each other, a beam passage is formed between them. The energy detector constitutes an energy measuring device together with a signal processing unit. A part of the ion beam having reached the interior of the irradiation nozzle is irradiated to a patient through the beam passage. When a part of the remaining ion beam enters the energy detector, electric charges generate in the energy detector. The signal processing unit determines energy of the ion beam based on a position within the energy detector at which electric charges have generated in maximum amount.

Abstract: Systems and methods are disclosed for protecting an EUV light source plasma production chamber optical element surface from debris generated by plasma formation. In one aspect of an embodiment of the present invention, a shield is disclosed which comprises at least one hollow tube positioned between the optical element and a plasma formation site. The tube is oriented to capture debris while allowing light to pass through the tube's lumen via reflection at relatively small angles of grazing incidence. In another aspect of an embodiment of the present invention, a shield is disclosed which is heated to a temperature sufficient to remove one or more species of debris material that has deposited on the shield. In yet another aspect of an embodiment of the present invention, a system is disclosed which a shield is moved from a light source plasma chamber to a cleaning chamber where the shield is cleaned.