245 results about "Alpha particle" patented technology

A method for producing 229Th includes the steps of providing 226Ra as a target material, and bombarding the target material with alpha particles, helium-3, or neutrons to form 229Th. When neutrons are used, the neutrons preferably include an epithermal neutron flux of at least 1×1013 n s−1·cm−2. 228Ra can also be bombarded with thermal and / or energetic neutrons to result in a neutron capture reaction to form 229Th. Using 230Th as a target material, 229Th can be formed using neutron, gamma ray, proton or deuteron bombardment.

An integrated circuit, method of forming the integrated circuit and a method of testing the integrated circuit for soft-error fails. The integrated circuit includes: a silicon substrate; a dielectric layer formed over the substrate; electrically conductive wires formed in the dielectric layer, the wires interconnecting semiconductor devices formed in the substrate into circuits; and an alpha particle emitting region in the integrated circuit chip proximate to one or more of the semiconductor devices. The method includes exposing the integrated circuit to an artificial flux of thermal neutrons to cause fission of atoms in the alpha particle emitting region into alpha particles and other atoms.

Applicant's present invention is a composite scintillator for neutron detection comprising a matrix material fabricated from an inorganic sol-gel precursor solution homogeneously doped with a liquid scintillating material and a neutron absorbing material. The neutron absorbing material yields at least one of an electron, a proton, a triton, an alpha particle or a fission fragment when the neutron absorbing material absorbs a neutron. The composite scintillator further comprises a liquid scintillating material in a self-assembled micelle formation homogeneously doped in the matrix material through the formation of surfactant-silica composites. The scintillating material is provided to scintillate when traversed by at least one of an electron, a proton, a triton, an alpha particle or a fission fragment. The scintillating material is configured such that the matrix material surrounds the micelle formation of the scintillating material. The composite scintillator is fabricated and applied as a thin film on substrate surfaces, a coating on optical fibers or as a glass material.

This application discloses a new, and useful computer implemented method and apparatus that can be used for the determination of SEU and SET disruptions in a cell or circuit, caused by ionizing particle strikes, including those caused by neutrons (cosmic rays), alpha particles or heavy ions. The method of the present invention includes a fast simulation tool (“TFIT”), which calculates the electrical effect of a particle's impact to a cell, or a circuit. The method is used to predict the soft error rate (SER) calculations and the FIT (number of failures-in-time) performance of designated test cell's design, depending on the type of particle environment specified. The method is designed to simulate the response of the cell or circuit to the stimuli caused by a particle strike. These stimuli are modeled as a “current source” placed between the drain and the source of each struck transistor.

An optimized trench capacitor structure which is useful as a decoupling capacitor or a storage capacitor can be manufactured without added process complexity. As an on-chip decoupling trench capacitor structure, the structure reduces the series resistance to outer and inner plates and results in an acceptable RC delay, while maintaining a high capacitance per unit area. As a storage capacitor with a buried shield, the trench capacitor structure exhibits high immunity to alpha particle and cosmic radiation induced failures. The trench capacitor structure which includes a buried n-well in a silicon substrate. A trench is formed in the substrate and extends through the buried n-well. A dielectric film is formed on an inner surface of the trench, and an inner plate formed as a polysilicon fill within the trench is connected to a surface n+ film formed during definition of peripheral source / drain contacts of the integrated circuit. An outer plate of the capacitor in the form of an out diffusion from the trench provides a low resistance electrical contact with the substrate. A number of these capacitors can be combined in a very efficient X-Y array of decoupling capacitors.

A structure and a method for reduction of soft error rates in integrated circuits. The structure including: a semiconductor substrate; and a stack of one or more wiring levels stacked from a lowermost wiring level to an uppermost wiring level, the lowermost wiring level nearer the semiconductor substrate than the uppermost wiring level; and an alpha particle blocking layer on a top surface of the uppermost wiring level of the one or more wiring levels, the blocking layer comprising metal wires and a dielectric material, the blocking layer having a combination of a thickness of the blocking layer and a volume percent of metal wires in the blocking layer sufficient to stop a predetermined percentage of alpha particles of a selected energy or less striking the blocking layer from penetrating into the stack of one or more wiring levels or the substrate.

A reactor system produces plasma rocket thrust using alpha-initiated atomic fuel pellets without the need for a critical mass of fissionable material. The fuel pellets include an outer layer reactive material to alpha particles to generate neutrons (e.g., porous lead or beryllium), an under-layer of fissionable material (e.g., thorium or enriched uranium), and an optional inner core of fusion material (e.g., heavy water ice, boron hydride). The pellets are injected one at a time into a charged reaction chamber containing a set of alpha beam channels, possibly doubling as ion accelerators, all directed toward a common point. Alpha particles converging on each successive pellet initiate an atomic reaction in the fissionable under-layer, via a neutron cascade from the pellet outer layer, producing plasma that is confined within the chamber. This may be enhanced by atomic fusion of the optional inner core. The resulting high-energy plasma creates electrostatic pressure on the chamber and is allowed to exit the chamber through a port. An ion accelerator at the exhaust port of the chamber accelerates outgoing plasma ions, possibly with added reaction mass, to generate the rocket thrust. An electric circuit that includes the charged chamber may collect the electrons in the plasma to help power the ion accelerator(s).

The present invention provides methods and apparatuses for detecting neurons, that provide high sensitivity, low cost, durability, portability, and scalability. Neutrons interacting with a 10B layer in the present invention result in expression of alpha particles from the 10B layer. The alpha particles can then be detected, for example with a silicon photodetector or an imaging array (e.g., arrays used in digital cameras).

A static ram cell is described. The cell includes a pair of cross-coupled transistors and a pair of diode-connected transistors operated from a wordline that provides power to the cell. The cell has three main operating modes, reading, writing and data retention. Reading is performed by sensing current flowing from a powered up wordline through a conductive one of the cross-coupled transistors. Writing is performed by pulsing the source of the conductive one of the cross-coupled transistors with a positive voltage to flip the conductive states of the cross-coupled transistors. Data retention is performed by using leakage currents to retain the conductive states of the cross-coupled transistors. A decoder for an array of static ram cells may be operated synchronously and in a pipelined fashion using a rotary traveling wave oscillator that provides the clocks for the pipeline. The cell capable of detecting an alpha particle strike with suitable circuitry.

Addition of capacitance to the storage nodes of static random access memory cells and other types of integrated circuits substantially increases Qcrit and substantially eliminates soft errors due to alpha particles; susceptibility to which would otherwise increase as integrated circuits are scaled to smaller sizes and manufactured at increased integration densities. Formation of the added capacitance as deep trench capacitors avoids any constraint on circuit or memory cell layout. Degradation of performance is avoided and performance potentially improved by permitting alteration of proportions of pull-down and pass gate transistors in view of the increased stability imparted by the added capacitors. One of the capacitor electrodes is preferably shorted to the supply voltage through an impurity well. Thus, the memory cell size can be reduced while greatly reducing susceptibility to soft errors; contrary to the effects of scaling at current and foreseeable feature size regimes.

A method for purifying tin includes exposing an electrolytic solution comprising tin to an ion exchange resin and depositing electrorefined tin from the electrolytic solution. The deposited electrorefined tin has alpha particle emissions of less than about 0.01 counts / hour / cm2 immediately after the deposition step, and an alpha emissivity of less than about 0.01 counts / hour / cm2 at least 90 days after the deposition step.

A method and counter for reducing the background counting rate in gas-filled alpha particle counters wherein the counter is constructed in such a manner as to exaggerate the differences in the features in preamplifier pulses generated by collecting the charges in ionization tracks produced by alpha particles emanating from different regions within the counter and then using pulse feature analysis to recognize these differences and so discriminate between different regions of emanation. Thus alpha particles emitted from the sample can then be counted while those emitted from the counter components can be rejected, resulting in very low background counting rates even from large samples. In one embodiment, a multi-wire ionization chamber, different electric fields are created in different regions of the counter and the resultant difference in electron velocities during charge collection allow alpha particles from the sample and counter backwall to be distinguished. In a second embodiment, a parallel-plate ionization chamber, the counter dimensions are adjusted so that charge collection times are much longer for ionization tracks caused by sample source alpha particles than for those caused by anode source alpha particles. In both embodiments a guard electrode can be placed about the anode's perimeter and secondary pulse feature analysis performed on signal pulses output from a preamplifier attached to this guard electrode to further identify and reject alpha particles emanating from the counter's sidewalls in order to further lower the counter's background.

The invention relates to the field of drug development against acute radiation injury caused by exposure to high-energy electromagnetic waves (X-rays, gamma rays) or particles (alpha particles, beta particles, neutrons). To date, there is no effective drug to ameliorate radiation injury after accidental exposure to ionizing irradiation. The invention provides a method of treating radiation injury of a subject in need thereof comprising administering to the subject a peptide, or functional analogue or derivative thereof, of smaller than 30 amino acids. Furthermore, the invention provides use of a peptide, or functional analogue or derivative thereof, of smaller than 30 amino acids for the production of a pharmaceutical composition for the treatment of a subject suffering from or believed to be suffering from radiation injury. In particular, the invention provides anti-radiation peptides having a dose reduction factor (DRF) against acute gamma irradiation of at least 1.10, said DRF determinable by testing which dose of radiation results in 50% mortality at 30 days (LD50 / 30) after whole body radiation (WBI) in a test group of mice treated with said peptide at 72 hours after WBI and, testing which dose of radiation results in 50% mortality at 30 days (LD50 / 30) after whole body radiation (WBI) in a control group of mice treated only with the vehicle of said peptide at 72 hours after WBI and wherein the DRF is calculated by dividing the LD50 / 30 of the peptide-treated animals by the LD50 / 30 of the vehicle-treated animals.

The charge state of ions produced by electrospray ionization is reduced in a controlled manner to yield predominantly singly charged ions through reactions with bipolar ions generated using a <210>Po alpha particle source or equivalent. The multiply charged ions generated by the electrospray undergo charge reduction in a charge reduction chamber. The charge-reduced ions are then detected using a commercial orthogonal electrospray TOF mass spectrometer, although the charge reduction chamber can be adapted to virtually any mass analyzer. The results obtained exhibit a signal intensity drop-off with increased oligonucleotide size similar to that observed with MALDI mass spectrometry, yet with the softness of ESI and without the off-line sample purification and pre-separation required by MALDI.

The present invention relates to the use of nanoscintillation systems, or nanoparticles containing fluor molecules, that can be used to detect an electron-emitting or alpha-particle-emitting radioisotope in the absence of organic-solvents commonly used in organic-based liquid scintillation cocktails. The invention also relates to compositions and use of three oil-in-water microemulsion precursors that can be engineered rapidly, reproducibly, and cost-effectively to produce useful nanoparticles less than 100 nanometers.

Compositions and methods are described for transparent glass composite having nanoparticles therein that scintillate in the presence of nuclear radiation, particularly gamma rays, but also x-rays, alpha particles, beta particles, and neutrons. The transparent glass composites can be prepared by a melt / cool process to produce the transparent glass composite. The wavelength of light emitted by the transparent glass composite can be tailored based on the materials used to make the glass composite. A detector that utilizes the transparent glass composite can measure nuclear radiation from numerous sources.

A self-powered microthermionic converter having an internal thermal power source integrated into the microthermionic converter. These converters can have high energy-conversion efficiencies over a range of operating temperatures. Microengineering techniques are used to manufacture the converter. The utilization of an internal thermal power source increases potential for mobility and incorporation into small devices. High energy efficiency is obtained by utilization of micron-scale interelectrode gap spacing. Alpha-particle emitting radioisotopes can be used for the internal thermal power source, such as curium and polonium isotopes.

A static ram cell is described. The cell includes a pair of cross-coupled transistors and a pair of diode-connected transistors operated from a wordline that provides power to the cell. The cell has three main operating modes, reading, writing, and data retention. Reading is performed by sensing current flowing from a powered-up wordline through a conductive one of the cross-coupled transistors. Writing is performed by pulsing the source of the conductive one of the cross-coupled transistors with a positive voltage to flip the conductive states of the cross-coupled transistors. Data retention is performed by using leakage currents to retain the conductive states of the cross-coupled transistors. A decoder for an array of static ram cells may be operated synchronously and in a pipelined fashion using a rotary traveling wave oscillator that provides the clocks for the pipeline. The cell is capable of detecting an alpha particle strike with suitable circuitry.

An apparatus for a user to conduct an accelerated soft error test (ASER) on a semiconductor sample is provided. The apparatus comprises a first component for holding the radiation source, where the radiation source may be either an alpha-particle or neutron-particle source. The apparatus comprises a second component for holding the semiconductor sample, where the semiconductor sample may be either a silicon wafer or semiconductor chip. The apparatus comprises a connecting assembly for placing the first component and the second component relative to each other at a plurality of positions that subject the semiconductor sample to a radiation stress from the radiation source at a plurality of stress efficiencies. Among the benefits provided are improved repeatability and credibility of ASER tests and reduced radiation exposures to operators of ASER tests.

An integrated circuit, comprising: a semiconductor substrate, a plurality of last metal conductors disposed above said substrate, a bottom metallic layer disposed on said last metal conductors, a top metallic layer, and an alpha absorber disposed between said bottom and top metallic layers, said alpha absorber consisting essentially of a high-purity metal which is an alpha-particle absorber. The metal is, for example, of Ta, W, Re, Os or Ir.

An improved solder bump composition and method advantageously employs a thin low-alpha layer of lead (Pb) deposited in close proximity to alpha particle sensitive devices, while ordinary (i.e., low cost) Pb is used for the bulk of the solder bump. This approach allows for reduced overall cost while still providing protection from alpha-particle induced soft errors. The low-alpha layer reduces the flux of alpha particle into devices in two ways. First, the low-alpha layer is itself essentially Pb210 free and therefore alpha particle emissions from the low-alpha layer are negligible. Second, the low-alpha layer is substantially opaque to alpha particles emitted by the ordinary Pb which includes Pb210. As a result, sensitive circuits on a semiconductor chip employing the improved solder bump are shielded from alpha particle emissions of the low-cost Pb210-containing portion of a solder bump.

A semiconductor device comprises a material layer adapted to efficiently stop alpha particles that are substantially generated within a solder bump of a flip chip device. The materials used for stopping the alpha particles are compatible with standard back-end processing and do not degrade adhesion of the solder bump to the remaining substrate. Moreover, a low electrical resistance is maintained and heat dissipation may be improved.

An alpha particle blocking structure and method of making the structure. The structure includes: a semiconductor substrate; a set of interlevel dielectric layers stacked from a lowermost interlevel dielectric layer closest to the substrate to a uppermost interlevel dielectric layer furthest from the substrate, each interlevel dielectric layer of the set of interlevel dielectric layers including electrically conductive wires, top surfaces of the wires substantially coplanar with top surfaces of corresponding interlevel dielectric layers; an electrically conductive terminal pad contacting a wire pad of the uppermost interlevel dielectric layer; an electrically conductive plating base layer contacting a top surface of the terminal pad; and a copper block on the plating base layer.

The invention provides a method for a simulation test about the comprehensive space radiation effect of a surface function material for a spacecraft, which belongs to the field of space environment engineering and can be applied to evaluation on the space environment effect of the surface function material for the spacecraft. When the spacecraft is in an on-orbit working, most surface function materials are directly exposed in the on-orbit environment, and the influence of the radiation environment is more severe. The surface function materials are irradiated by electrons, protons, alpha particles and heavy ions with wider energy and flux, and the radiation of all the particles can lead the performances of the surface function materials to be deteriorated. In a long-life design of a satellite, the capability of bearing the influence of the environment with comprehensive space radiation needs to be inspected. The method provided by the invention has an important significance in evaluation on the ground simulation test about the orbit radiation effect of the surface function material for the spacecraft.

A parallel computer system adds entropy to improve the quality of random number generation by using parity errors as a source of entropy because parity errors are influenced by external forces such as cosmic ray bombardment, alpha particle emission, and other random or near-random events. By using parity errors and associated information to generate entropy, the quality of random number generation in a parallel computer system is increased.

A structure and a method for forming the same. The structure includes an integrated circuit comprising N chip electric pads, wherein N is a positive integer, and wherein the N chip electric pads are electrically connected to a plurality of devices on the integrated circuit. The structure further includes N solder bumps corresponding to the N chip electric pads. A semiconductor interposing shield is sandwiched between the integrated circuit and the N solder bumps. The structure further includes N electric conductors (i) passing through the semiconductor interposing shield and (ii) electrically connecting the N solder bumps to the N chip electric pads.

An alpha particle blocking structure and method of making the structure. The structure includes: a semiconductor substrate; a set of interlevel dielectric layers stacked from a lowermost interlevel dielectric layer closest to the substrate to a uppermost interlevel dielectric layer furthest from the substrate, each interlevel dielectric layer of the set of interlevel dielectric layers including electrically conductive wires, top surfaces of the wires substantially coplanar with top surfaces of corresponding interlevel dielectric layers; an electrically conductive tot final pad contacting a wire pad of the uppermost interlevel dielectric layer; an electrically conductive plating base layer contacting a top surface of the terminal pad; and a copper block on the plating base layer.

The invention discloses a real-time monitoring device for the neutron flux in a fission reaction. The device is characterized in that a fast neutron conversion body (1), a fluorescent light reflection tube (3), a boron plastic flash body (2), a Cherenkov light reflection tube (5) and a Cherenkov radiation body (4) are arranged in the incident direction of particles in sequence; neutrons and gamma rays enter the boron plastic flash body (2) to interact with substances to generate e+ / e-, recoil protons and alpha particles, the e+ / e-, the recoil protons and the alpha particles are excited to generate fluorescent light, and the fluorescent light enters a first photoelectric multiplier tube (7) through reflection of the fluorescent light reflection tube (3) and is amplified through an amplifier (10) to obtain neutron and gamma information; after secondary particles enter the Cherenkov radiation body, only e+ / e- generates Cherenkov light, and the Cherenkov light is amplified through a second photoelectric multiplier tube to obtain gamma information; two signals are subjected to subtraction to obtain neutron flux information. According to the device, the n and gamma signals are judged in combination with the pulse rise time difference, so that the measurement precision of the pulsed neutron flux is further improved.

A method of modeling soft errors in a logic circuit uses two separate current sources inserted at the source and drain of a device to simulate a single event upset (SEU) caused by, e.g., an alpha-particle strike. In an nfet implementation the current flows from the source or drain toward the body of the device. Current waveforms having known amplitudes are injected at the current sources while simulating operation of the logic circuit and the state of the logic circuit is determined from the simulated operation. The amplitudes of the current waveforms can be independently adjusted. The simulator monitors the state of device and makes a log entry when a transition occurs. The process may be repeated for other devices in the logic circuit to provide an overall characterization of the susceptibility of the circuit to soft errors.

A detector circuit and method for detecting a silicon well voltage or current to indicate an alpha particle or cosmic ray strike of the silicon well. One significant application for the detection circuit of the present invention is for the redundancy repair latches that are used in SRAMs. The redundancy repair latches are normally written once at power-up to record failed latch data and are not normally written again. If one of the latches changes states due to an SER (Soft Error Rate-such as a strike by an alpha particle or cosmic ray) event, the repair data in the redundancy latches of the SRAM would now be incorrectly mapped. The detector circuit and method monitors the latches for the occurrence of an SER event, and responsive thereto issues a reload of the repair data to the redundancy repair latches. A first embodiment of the detector circuit differentially detects the floating voltages of first and second silicon wells during periods of non-operation of the circuits fabricated in the first and second silicon wells. In a second embodiment, a detector circuit monitors the background voltage level of a single silicon well over first and second consecutive periods of time. A second application for the detection circuit is for traditional logic circuits.