47 results about "Damping constant" patented technology

A method and system for providing a magnetic element that can be used in a magnetic memory is disclosed. The magnetic element includes pinned, spacer, free, and spin barrier layers. The spacer layer is nonmagnetic and resides between the pinned and free layers. The free layer can be switched using spin transfer when a write current is passed through the magnetic element. The free layer resides between the spacer layer and the spin barrier layer. The spin barrier layer is configured to reduce an outer surface contribution to a damping constant of the free layer. In one aspect, the spin barrier layer has a high areal resistance and may substantially eliminate spin pumping induced damping. In another aspect, the magnetic element also includes a spin accumulation layer between the spin barrier and free layers. The spin accumulation layer has a high conductivity, preferably being metallic, and may have a long spin diffusion length.

A magnetic memory including a plurality of magnetic junctions and at least one spin-orbit interaction (SO) active layer is described. Each of the magnetic junctions includes a pinned layer, a free layer and a nonmagnetic spacer layer between reference and free layers. The free layer has at least one of a tilted easy axis and a high damping constant. The tilted easy axis is at a nonzero acute angle from a direction perpendicular-to-plane. The high damping constant is at least 0.02. The at least one SO active layer is adjacent to the free layer and carries a current in-plane. The at least one SO active layer exerts a SO torque on the free layer due to the current. The free layer is switchable using the SO torque.

The invention relates to a method and a device (1) for the online-detection of a deterioration in the state of an insulation in an electric machine (2). A stepped voltage is applied to the winding(s) (3) of the machine (2) with the aid of a converter (41), and the current (i) induced in this manner, and/or the time derivative (di/dt) thereof, is acquired as a measurement signal with the aid of at least one sensor (6, 7, 8) and is then oversampled with a frequency higher than the frequencies characteristic for settling. The signal obtained by said oversampling is then evaluated with regard to parameters of the settling process such as overshooting (Ah) and/or natural frequency (1/delta T) and/or a damping constant, in order to detect any deterioration in the insulation.

A method and system provide a magnetic junction usable in a magnetic device. The magnetic junction includes a pinned layer, a nonmagnetic spacer layer, a free layer, and at least one damping reduction layer. The free layer has an intrinsic damping constant. The nonmagnetic spacer layer is between the pinned layer and the free layer. The at least one damping reduction layer is adjacent to at least a portion of the free layer and configured to reduce the intrinsic damping constant of the free layer. The magnetic junction is configured such that the free layer is switchable between a plurality of stable magnetic states when a write current is passed through the magnetic junction.

Provided are an apparatus and method for imaging the subsurface structure of a target area by using waveform inversion. In the apparatus and method, the subsurface structure of a target area is estimated using waveform inversion of a seismic signal in the frequency domain, the Laplace domain, or the Laplace-Fourier domain, and an objective function is defined by applying a weighting function such that the objective function makes a different contribution for each frequency, each Laplace damping constant, or each Laplace-Fourier damping constant. The objective function is not limited to a particular type of objective function and a weighting function can be automatically determined when a gradient vector for each frequency, each Laplace damping constant, or each Laplace-Fourier damping constant is normalized. In addition, a gradient direction for all frequencies can be defined by applying another weighting function to the sum of respective gradient vectors for all frequencies, all Laplace damping constants, or all Laplace-Fourier damping constants, wherein the weighting function can also be automatically determined by normalization.

In an MR element constituted in such a manner that a pinned layer whose magnetization direction is fixed, a nonmagnetic spacer layer, and a free layer whose magnetization direction is changed according to an external magnetic field, are laminated in this order; the free layer has a multilayer constitution including a magnetic body mixed with an element having 4f electrons at a ratio of 2 at % to 25 at. %. Specifically, the first layer in contact with the spacer layer, the third layer, the fifth layer, and the seventh layer of the free layer are formed by mixing Nd, Sm, Gd, or Tb into CoFe having a ratio of Co less than or equal to 70 at. %. The second layer and the sixth layer of the free layer are formed by mixing Nd, Sm, Gd, or Tb into NiFe having a ratio of Ni greater than or equal to 70 at. % and less than 100 at. %. The third layer of the free layer is Cu. A damping constant of the free layer is greater than 0.018.

A tunneling magnetoresistance (TMR) device, like a TMR read head for a magnetic recording disk drive, has low magnetic damping, and thus low mag-noise, as a result of the addition of a ferromagnetic backing layer to the ferromagnetic free layer. The backing layer is a material with a low Gilbert damping constant or parameter α, the well-known dimensionless coefficient in the Landau-Lifshitz-Gilbert equation. The backing layer may have a thickness such that it contributes up to two-thirds of the total moment/area of the combined free layer and backing layer. The backing layer may be formed of a material having a composition selected from (Co_xFe_(100-x))_(100-y)X_y, (Co₂Mn)_(100-y)X_y and (Co₂Fe_xMn_(1-x))_(100-y)X_y, where X is selected from Ge, Al and Si, and (Co₂Fe)_(100-y)Al_y, where y is in a range that results in a low damping constant for the material.

A passive deployable antenna mechanism is provided, which is characterized in that the device comprises: an antenna mounting plate (1), a damping speed stabilization mechanism (2), an antenna unfolding arm (3), a two-dimensional pointing mechanism (4), a spaceborne Antenna (5) and compression release device (6), damping and speed-stabilizing mechanism (2) are fixedly installed on one end of antenna mounting plate (1), and one end of antenna expansion arm (3) is connected with damping and speed-stabilizing mechanism (2), and another One end is connected to one end of the two-dimensional pointing mechanism (4), and the other end of the two-dimensional pointing mechanism (4) is connected to the satellite antenna (5), and the compression release device (6) is installed on the antenna unfolding arm (3), two Between the three-dimensional pointing mechanism (4), the spaceborne antenna (5) and the antenna mounting plate (1), it is used for locking the antenna mechanism in the satellite launching state, and releasing the antenna mechanism after the satellite enters orbit.

An image forming apparatus includes: a driving source configured to generate power; a first rotator configured to be drivingly rotated by the power generated by the driving source; a first power transmission system configured to transmit the power from the driving source to the first rotator; a second rotator configured to be drivingly rotated by the power generated by the driving source; and a second power transmission system configured to transmit the power to the second rotator from the first power transmission system. A damper having a torsion spring constant and a torsion viscous damping constant making a maximum positional change value of the first rotator equal to or smaller than a predetermined positional change value is disposed between the first power transmission system and the second power transmission system.

A Laplace transform system comprising a processor, a measured time domain wavefield, a velocity model, and Laplace damping constants, wherein the processor is programmed to calculate a substantially about zero frequency component of a Fourier transform of a time domain damped wavefield, wherein the time domain damped wavefield is damped by the Laplace damping constants to obtain long wavelength velocity information for deeper subsurface regions.

A drilling rig apparatus is disclosed for mitigating stick-slip using a saver sub that is compatible with different top drives. The saver sub includes a smart material adjustable whenever a stand is added to the drill string to have different spring characteristics to generally match the impedance of the top drive to the impedance of the drill string. The saver sub also includes a magneto rheological fluid that is adjusted whenever a stand is added to the drill string to compensate for the changed characteristics of the drill string. The damping constant implemented by the MR fluid enables the saver sub to absorb stick-slip vibrations at the top drive. Each time that a stand is connected to the drill string, the spring and damping constants may be updated to accommodate the changing characteristics of the drill string.

A method reduces the Q factor of the resonant frequency response of a torsional oscillator system in a laser printer, where the Q factor is expressed as a function of the resonant frequency and 3 dB bandwidth of the frequency response. The frequency response of the torsional oscillator system is a function of at least a rotational inertia, a spring constant and a damping constant. The method includes the steps of decreasing the rotational inertia of the torsional oscillator system by a first factor, and decreasing the spring constant by a second factor that is substantially equal to the first factor. The method generally increases component yields, thereby reducing component costs. Also, laser printers using torsion oscillators having reduced Q factors may be used over a wider speed range. Conversely, a single laser printer model may be used at a single speed, rather than at speeds that vary due to variations in resonant frequency. The method also provides for greater freedom of movement of the operating point of the printer during printer development.