93 research outputs found
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Streaked, x-ray-transmission-grating spectrometer
A free standing x-ray transmission grating has been coupled with a soft x-ray streak camera to produce a time resolved x-ray spectrometer. The instrument has a temporal resolution of approx. 20 psec, is capable of covering a broad spectral range, 2 to 120 A, has high sensitivity, and is simple to use requiring no complex alignment procedure. In recent laser fusion experiments the spectrometer successfully recorded time resolved spectra over the range 10 to 120 A with a spectral resolving power, lambda/..delta..lambda of 4 to 50, limited primarily by source size and collimation effects
Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET
The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR
23rd IAEA Fusion Energy Conference: summary of sessions EX/C and ICC
An overview is given of recent experimental results in the areas of innovative confinement concepts, operational scenarios and confinement experiments as presented at the 2010 IAEA Fusion Energy Conference. Important new findings are presented from fusion devices worldwide, with a strong focus towards the scientific and technical issues associated with ITER and W7-X devices, presently under construction
Relationship of edge localized mode burst times with divertor flux loop signal phase in JET
A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM
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Simple, compact, high brightness source for x-ray lithography and x-ray radiography
A simple, compact, high brightness x-ray source has recently been built. This source utilizes a commercially available, cylindrical geometry electron beam evaporator, which has been modified to enhance the thermal cooling to the anode. Cooling is accomplished by using standard, low-conductivity laboratory water, with an inlet pressure of less than 50 psi, and a flow rate of approx.0.3 gal/min. The anode is an inverted cone geometry for efficient cooling. The x-ray source has a measured sub-millimeter spot size (FWHM). The anode has been operated at 1 KW e-beam power (10 KV, 100 ma). Higher operating levels will be investigated. A variety of different x-ray lines can be obtained by the simple interchange of anodes of different materials. Typical anodes are made from easily machined metals, or materials which are vacuum deposited onto a copper anode. Typically, a few microns of material is sufficient to stop 10 KV electrons without significantly decreasing the thermal conductivity through the anode. The small size and high brightness of this source make it useful for step and repeat exposures over several square centimeter areas, especially in a research laboratory environment. For an aluminum anode, the estimated Al-K x-ray flux at 10 cms from the source is 70 ..mu..W/cm/sup 2/
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EUV lithography cost of ownership analysis
The cost of fabricating state-of-the-art integrated circuits (ICs) has been increasing and it will likely be economic rather than technical factors that ultimately limit the progress of ICs toward smaller devices. It is estimated that lithography currently accounts for approximately one-third the total cost of fabricating modem ICs({sup 1}). It is expected that this factor will be fairly stable for the forseeable future, and as a result, any lithographic process must be cost-effective before it can be considered for production. Additionally, the capital equipment cost for a new fabrication facility is growing at an exponential rate (2); it will soon require a multibillion dollar investment in capital equipment alone to build a manufacturing facility. In this regard, it is vital that any advanced lithography candidate justify itself on the basis of cost effectiveness. EUV lithography is no exception and close attention to issues of wafer fabrication costs have been a hallmark of its early history. To date, two prior cost analyses have been conducted for EUV lithography (formerly called {open_quotes}Soft X-ray Projection Lithography{close_quotes}). The analysis by Ceglio, et. al., provided a preliminary system design, set performance specifications and identified critical technical issues for cost control. A follow-on analysis by Early, et.al., studied the impact of issues such as step time, stepper overhead, tool utilization, escalating photoresist costs and limited reticle usage on wafer exposure costs. This current study provides updated system designs and specifications and their impact on wafer exposure costs. In addition, it takes a first cut at a preliminary schematic of an EUVL fabrication facility along with an estimate of the capital equipment costs for such a facility
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Precision manufacturing using advanced optical interference lithography. Final report
Goal was to develop interference lithography (IL) as a reliable process for patterning large-area, deep-submicron scale field emission arrays for field emission display (FED) applications. We have developed a system based on IL which can easily produce an array of 0.2-0.5 micron emitters over large area (up to 400 sq. in. to date) with better than 5% height and spacing uniformity. Process development as a result of this LDRD project represents a significant advance over the current state of the art for FED manufacturing and is applicable to all types of FEDs, independent of the emitter material. Ability of IL to pattern such structures simultaneously and uniformly on a large format has application to other technology areas, such as dynamic random access memory (DRAM) production and magnetic media recording
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EUVL reticle factory model and reticle cost analysis
The key issues in reticle manufacturing are cost and delivery time, both of which are dependent upon the yield of the process line. To estimate the cost and delivery time for EUVL reticles in commercial manufacturing, we have developed the first model for an EUV reticle factory which includes all the tools required for a presumed EUVL reticle fabrication process. This model includes the building, support tools and sufficient ``in-line`` process tools for the manufacture of (more than) 2500 reticles per year. Industry specifications for the tool performance are used to determine the number of tools required per process step and the average number of reticles fabricated per year. Building and capital equipment depreciation costs, tool installation costs, tool maintenance costs, labor, clean room costs, process times and process yields are estimated and used to calculate the yearly operating cost of the reticle factory and the average reticle fabrication cost. We estimate the sales price of an EUV reticle to be 120K for ``leading-edge.`` The average reticle fabrication time is calculated for three different process-line yields
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EUV reticle pattern repair experiments using 10 KeV neon ions
Any potential lithography must demonstrate an industrially-compatable reticle pattern repair process before the lithographic process can be seriously considered for production. Repair of clear defects on ELTV reticles (i.e., regions on the mask which are reflective and should be non-reflective) requires the deposition of a thin layer of absorbing material. This process has been demonstrated in commercially available tools which were originally developed to repair proximity-print x-ray lithography masks. However, the repair of opaque defects (i.e., the recovery of reflectivity from regions on the reticle covered with an absorber) is more difficult. Opaque defect repair requires the removal of the absorber layer without damaging the underlying multilayer, a process which could degrade the mirror reflectivity. While opaque defect repair processes have been demonstrated in a research environment these processes may not be commercially suitable. We are developing reticle repair processes that will be consistent with a commercially available repair tool. In this paper, we report on our first results
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