Abstract:
A method of producing a corrected beam of charged particles for use in a charged-particle microscope, comprising the following steps: - Providing a non-monoenergetic input beam 3a of charged particles; - Passing said input beam through an optical module comprising a series arrangement of: –ª A stigmator 33, thereby producing an astigmatism-compensated, energy-dispersed intermediate beam 3b with a particular monoenergetic line focus direction; –ª A beam selector 37, comprising a slit 43-43b' that is rotationally oriented so as to match a direction of the slit to said line focus direction, thereby producing an output beam 3d comprising an energy-discriminated portion of said intermediate beam.
Abstract:
A mass analyzer includes two rotating electric field (REF) units, sinusoidal signal generators and a means for separation of dispersed ions. The REF units include a plurality of elongated electrodes surrounding a central axis, and are lined in tandem at elongated direction. Sinusoidal signals are applied to the electrodes to rotate electric fields within each REF unit. The means for separation is placed adjacent the downstream end of the 2nd REF unit. Ions enter the 1st REF unit, diverge outwards and leave the 1st REF unit on off-axis positions. The ions successively enter the 2nd REF unit and converge inwards because of 180 degrees phase difference from the 1st REF unit. Specified mass ions return to and travel along the central axis. However, unspecified mass ions deviate from the central axis and travel apart from the central axis. The means for separation separates specified ions from unspecified ions.
Abstract:
In a retarding potential type energy analyzer including a front grid electrode 21, reference grid electrode 22 and rear grid electrode 23 sequentially arranged, with a predetermined amount of potential difference given between the reference grid electrode 22 and the front grid electrode 21 to form an upward potential gradient as well as a potential difference given between the reference grid electrode 22 and the rear grid electrode 23 to form a downward potential gradient, the grid electrodes are arranged so that the distance between the reference grid electrode 22 and the rear grid electrode 23 is shorter than the distance between the reference grid electrode 22 and the front grid electrode 21, or the potential difference between the reference grid electrode 22 and the rear grid electrode 23 is made to be greater than the potential difference between the reference grid electrode 22 and the front grid electrode 21.
Abstract:
An electron energy loss spectrometer is described having a direct detection sensor, a high speed shutter and a sensor processor wherein the sensor processor combines images from individual sensor read-outs and converts a two dimensional image from said sensor into a one dimensional spectrum and wherein the one dimensional spectrum is output to a computer and operation of the high speed shutter is integrated with timing of imaging the sensor. The shutter is controlled to allow reduction in exposure of images corresponding to the individual sensor readouts. A plurality of images are exposed by imaging less than the full possible exposure and wherein the plurality of images are combined to form a composite image. The plurality of images can be comprised of images created by exposing the sensor for different exposure times.
Abstract:
The present invention relates to a method for determining at least one parameter related to charged particles emitted from a particle emitting sample (11), e.g. a parameter related to the energies, the start directions, the start positions or the spin of the particles. The method comprises the steps of guiding a beam of charged particles into an entrance of a measurement region by means of a lens system (13), and detecting positions of the particles indicative of said at least one parameter within the measurement region. Furthermore, the method comprises the steps of deflecting the particle beam at least twice in the same coordinate direction before entrance of the particle beam into the measurement region. Thereby, both the position and the direction of the particle beam at the entrance (8) of the measurement region (3) can be controlled in a way that to some extent eliminates the need for physical manipulation of the sample (11). This in turn allows the sample to be efficiently cooled such that the energy resolution in energy measurements can be improved.