Abstract:
In a secondary ion mass spectrograph, the electrical power supply voltages controlling and pertaining to the polarity of the target secondary ions are all switched between opposite polarities simultaneously while the deflection of the primary ion beam is automatically corrected for any error that may result from the polarity switch-over. This allows quick alternation of the polarity of target ions without loss of accuracy of the primary beam scan. The correction to the primary beam deflected may be predetermined under specific observing conditions or may be derived from theoretical considerations.
Abstract:
Disclosed is an electromagnetic lens polepiece structure for use in an electron microscope comprising an upper polepiece and an opposite lower polepiece, each having a lens bore, wherein the lens bore portion of the upper polepiece protrudes toward the lens bore of the lower polepiece. The protrudant lens bore portion allows the provision of an X-ray conducting bore for the measurement without disturbing the magnetic field of the lens. This makes it possible a smaller lens bore and, consequently, the spherical aberration is reduced and the resolution of the microscope is improved. The protrudant lens bore structure allows the upper polepiece to be divided into two sections so that the bore section can be replaced easily for the measurement of X-rays.
Abstract:
The invention provides a process and device for the ionic analysis of an insulating sample brought to a given negative potential, of the type in which a target on the surface of the sample to be analyzed is bombarded by means of a primary electron beam and negative ions emitted by the bombarded target are used for producing an ion image of the sample. An electron beam whose normal speed component cancels out just at level of the surface of the target is directed perpendicularly to the target.The device comprises for this purpose a filament, brought substantially to the same negative potential as the sample, which emits the electron beam. The electron beam, after emission, is deflected by a magnetic prism so as to be brought into coincidence with the optical axis of the negative ion beam emitted by the target.
Abstract:
A combined objective and emission lens for a microbeam probe is described which is suitable for primary and secondary particles of the same charge sign, by which lens a bundle of primary rays of comparatively high energy can be focused on a very small spot of a plane sample surface and the secondary particles emitted by this spot can be collected into a collimated bundle of secondary rays which leaves the combined lens in a direction substantially opposite to the bundle of primary rays. In the present combined lens, the field strength between the sample surface and the lens electrode most closely adjacent to it is very high, in contrast to the known combined objective and emission lenses, so that a small emissivity of the secondary beam with a small diameter at the same time of the primary beam spot and an effective collection and collimation of the secondary particles are ensured. Certain embodiments can be changed over optionally to operation with primary and secondary particles of the same or opposite polarity.
Abstract:
An emission-electron microscope comprises an evacuated chamber with a superconducting magnet at one end generating a region of very high field strength. In this region a specimen is mounted and the surface of the specimen is irradiated with photons, typically x-ray or hard ultra-violet, from a source. As a result the specimen emits photo-electrons. The magnetic field is axially symmetrical along the length of the chamber and emitted electrons spiral about the lines of force traveling down the chamber into a region of lower magnetic field controlled by electro-magnet coils. Transverse kinetic energy of the electrons is converted into energy along the lines of force of the magnetic field and the divergence of the magnetic field lines causes electrons to produce on a detector an expanded electron image indicative of the distribution of electron flux across the surface region of the specimen. The emission-electrons may be produced by other stimulation methods, for example neutral atoms or heat (thermal electrons) and arrangements may be provided to permit only electrons of predetermined energy reaching the detector.
Abstract:
An apparatus according to the present invention for irradiating a specimen with charged particle beams comprises a single charged particle generating source from which the charged particle beams formed of electrons and negative ions, respectively, can be simultaneously derived; a specimen holder on which the specimen is placed; and charged particle irradiation means which is interposed between the charged particle generating source and the specimen holder in order to focus the charged particle beams and to irradiate the surface of the specimen with the focused beams, and which includes at least one magnetic lens and at least one electrostatic lens that are individually disposed.
Abstract:
An X-ray spectrometer which is arranged inside an evacuatable housing and which comprises a wavelength dependent X-ray detection system and, for irradiating the specimen to be examined, an electron source with an electron deflection system for generating an electron beam and an X-ray source for generating an X-ray beam. The X-ray source consists of an anticathode on which the electron beam can be directed by the electron deflection system in order to generate the X-ray beam.
Abstract:
An ion scattering spectrometer (ISS) providing enhanced sensitivity, reduced background, and preferential detection of low-mass scattered ions over that of high-mass sputtered ions is disclosed. These advantages are accomplished by a biasing arrangement which maintains a potential difference between the analyzer exit and the detector input at less than 30 volts and substantially eliminates the high potential provided on detector inputs of prior art ion scattering spectrometers which attracted and thereby accelerated ions prior to impinging on the inputs.
Abstract:
A specimen containing biological cells is exposed to an electron beam. The secondary electrons emitted from the specimen are measured. Specimens with and without malignancy exhibit differences in magnitude of charging under an electron beam and differences in secondary electron energy distributions.
Abstract:
A device for measuring electron densities at a given energy level in an electron beam or the like having strong background noise, for example, in the detection of Auger electric energy spectrums. An electron analyzer passes electrons at the given energy level and at the same time or ad seriatum electrons of at least one adjacent energy level. Detecting means associated therewith produce signals indicative of the densities of the electrons at each energy level and combine these signals to produce a signal indicative of the density of the electrons of the given energy level absent background noise.