摘要:
An electronic measurement circuit for high speed comparison of the relative amplitudes of a predetermined number of electrical input signals independent of variations in the magnitude of the sum of the signals. The circuit includes a high speed electronic switch that is operably connected to receive on its respective input terminals one of said electrical input signals and to have its common terminal serve as an input for a variable-gain amplifier-detector circuit that is operably connected to feed its output to a common terminal of a second high speed electronic switch. The respective terminals of the second high speed electronic switch are operably connected to a plurality of integrating sample and hold circuits, which in turn have their outputs connected to a summing logic circuit that is operable to develop first, second and third output voltages, the first output voltage being proportional to a predetermined ratio of sums and differences between the compared input signals, the second output voltage being proportional to a second summed ratio of predetermined sums and differences between said input signals, and the third output voltage being proportional to the sum of signals to the summing logic circuit. A servo system that is operably connected to receive said third output signal and compare it with a reference voltage to develop a slowly varying feedback voltage to control the variable-gain amplifier in said common amplifier-detector circuit in order to make said first and second output signals independent of variations in the magnitude of the sum of said input signals.
摘要:
A primary particle beam irradiation apparatus comprising a stage on which a target is placed; a device for irradiating a predetermined scan region on the stage with a primary particle beam; a secondary ion sensor for detecting a secondary ion, generated by an irradiation of the primary particle beam, from the stage or the target; and a device, connected to the irradiating device and the secondary ion sensor, for controlling the irradiating means on the basis of an output signal from the secondary ion sensor.Further, a method for irradation of a primary particle beam comprising the step of detecting the irradiation position of a primary particle beam scanned on a target over a predetermined width or predetermined region by using the output of a secondary ion sensor provided near the surface of the target; the step of correcting the deviation of the irradiation position based on the information of the irradiation position which is detected, and further scanning the primary particle beam to irradiate the surface of the target based on the information obtained at the correction step.
摘要:
A charged beam apparatus comprises vacuum vessels for accommodating superconducting coils in a heat-insulating manner, a charged beam vacuum chamber that provides a passage for a charged beam, and a vacuum chamber for synchrotron radiation that is coupled to the charged beam vacuum chamber and through which is passed the synchrotron radiation that is produced by the charged beam when it is bent by the superconducting coils, the vacuum vessels being detachable from the charged beam vacuum chamber.
摘要:
An nth order magnetic multipole arrangement for influencing the trajectory of charged particles is disclosed. In order to avoid using structural parts that are manufactured separately, it has been found to provide as the multipole arrangement, the stator of a multi-pole alternating current machine, the stator winding of which is fed by a voltage source in such a way that the produce of current and number of turns (number of ampere turns) in a groove or group of grooves disposed under the azimuth angle .theta. is proportional to cos (n .theta.), n corresponding to the order (order number) of the multipole arrangement, and the factors a and b being taken from the ratio b/a which states the orientation of the multipole relative to the azmith angle .theta.=0. As the multipole arrangement there may be provided also a stator, excited by permanent magnets, of a direct current machine.
摘要:
An apparatus for deflecting and focusing a beam of neutral particles for operating on extremely small workpieces, such as for doping or inscribing micro-electronic components, has a deflection system for generating at least one magnetic field through which the beam of neutral particles is directed for focusing and shaping of the beam on the workpiece. The lens system may include one or more six-pole or eight-pole lenses.
摘要:
An explosively operated device by which a strong magnetic field pulse and an electric current pulse of microseconds duration is produced. A cylindrical magnet is used to initiate the field, and its energy source is an explosive filled metal tube. Within the converter itself, the lines of magnetic flux are essentially axial. When an explosive charge in the central tube is detonated, the end of the tube flares radially, and the tube begins to expand along its length. As it does so, the tube compresses the magnetic field against the inner surface of a magnet. Simultaneously, a helical coil inside the converter experiences a rapid increase in flux density, thus satisfying Faraday's law. This interaction causes a pulse of electric current to be fed into the turns of the magnetocumulative generator as its initial magnetic field is maximized. As the central tube expands against the inside of the coil, it shorts out the turns one-by-one as the detonation wave travels axially along the converter. This action progressively reduces the inductance of the circuit, thus increasing the current output of the converter.
摘要:
A first order achromatic magnetic deflection system for use in conjunction with a charged particle accelerator is realized from a stepped gap magnet wherein charged particles propagating through the system are subject to at least two adjacent homogeneous magnetic fields in adjacent regions (54 and 56) in traversing one-half of a symmetric trajectory through the system. A quadrupole singlet element Q disposed substantially at the entrance plane of such a symmetric system makes possible the coincidence of the waists of the beam in both the vertical (transverse) and (radial) bending planes.
摘要:
In an exemplary system, a two stage deflection system responds to a first control signal of low frequency such that extra-axial chromatic errors due to electrostatic and magnetic deflection are made equal and opposite. The magnetic and electrostatic deflection systems may be arranged in either order along the beam path just so the low frequency electrostatic deflection is one-half the magnetic deflection and is in an opposite direction at the target. A second higher frequency control signal controls only the electrostatic deflection system. Preferably the deflection velocities at the target produced by the two control signals are equal, with the higher frequency being an integral multiple of the lower frequency and with the control signals being poled to provide opposite deflections. When the two deflection velocities are superimposed, the resultant is then a step type deflection as a function of time.
摘要:
The accelerator includes a source of an ensemble or bunch of ions and a plurality of relatavistic electron beam stages, each of which generate a high current electron beam which in turn are injected along the accelerator centerline in a timed sequence to accelerate the ion bunch to increasingly high kinetic energy levels. In each relatavistic electron beam stage, a region of high electric charge is created by the discharge of a high current, short duration pulse between a cathode and anode. The electron beam created by the discharge stops a short distance beyond the anode, due to the buildup of its electric charge, thereby creating a region of high charge which accelerates the ion bunch. Each successive relatavistic electron beam stage is timed to fire when the ion bunch arrives at the region of high charge of that stage, and in operation, increases the kinetic energy of the ion bunch by a factor equal to or greater than the kinetic energy of the electron beam.
摘要:
The accelerating structure comprises a resonant cavity within which are placed at least two longitudinal conducting supports. One end of each support is electrically connected to the cavity in such a manner as to be in quarter-wave resonance and in opposite phase. Drift tubes are electrically connected alternately to each of the two supports. The supports are electrically connected respectively to each end of the lateral face of the cavity.