Abstract:
In an ion beam apparatus wherein ions are generated by the collision of electrons from a filamentary emitter with gas atoms in the vicinity of an electron-attracting grid structure, with subsequent extraction of the ions so generated from the vicinity of the grid structure and the focusing of these ions into a beam by an electrostatic lens system, a new way of mounting the ion extractor and the electrostatic lens system is disclosed which facilitates the removal and replacement of the filament and the grid structure. A configuration of the grid structure is also disclosed which optimizes the profile and the current density of the ion beam.
Abstract:
The hollow cathode gas discharge device is configured with a maximized cathode-to-anode area ratio to operate in a lowpressure glow discharge mode to generate a plasme of adequate density from which electrons or ions can be extracted and accelerated. This permits the gas pressure to be kept low to avoid Paschen breakdown in the high voltage acceleration region. The invention herein described was made in the course of or under a Contract or subcontract thereunder with the Department of the Navy.
Abstract:
An ion source modified by an additional electrode, designated as a scraper electrode, positioned between the anode and extractor electrode, having an aperture slightly less than the source plasma aperture, and adapted to carry a pre-determined voltage in reference to the anode. It has been found that the scraper electrode intercepts and removes ions at the periphery of the beam cross-sectional area and this is the region that contains ions that contribute most greatly to the increased emittance. The central, non-intercepted cross-sectional area therefore has a much reduced emittance. The voltage on the scraper electrode should be such as to not disturb or distract the electric field between anode and extractor electrode.
Abstract:
Methods of marking paper products and marked paper products are provided. Some methods include irradiating the paper product to alter the functionalization of the paper.
Abstract:
There is provided an emitter structure, a gas ion source including the emitter structure, and a focused ion beam system including the gas ion source. The emitter structure includes a pair of conductive pins which are fixed to a base member, a filament which is connected between the pair of conductive pins, and an emitter which is connected to the filament and has a sharp tip. A supporting member is fixed to the base material, and the emitter is connected to the supporting member.
Abstract:
Methods of marking paper products and marked paper products are provided. Some methods include irradiating the paper product to alter the functionalization of the paper.
Abstract:
A pulsed plume of laser ablated photo-ionizable material is emitted from a target in a vacuum, and a pulsed beam of light thereafter produces ionization of two plume sections straddling a central nonionized plume portion. A mask is provided, intermediate the plume and the laser generating the ionizing pulsed beam of light, to shield the central plume portion to prevent ionization thereof. The ionized portions of the plume are swept away from the vicinity of the non-ionized plume portion by a magnetic field, and the remaining nonionized portion passes through an aperture in a retrieval mask to produce the output of the atomic source.
Abstract:
An improved magnetically-confined anode plasma pulsed ion beam source. Beam rotation effects and power efficiency are improved by a magnetic design which places the separatrix between the fast field flux structure and the slow field structure near the anode of the ion beam source, by a gas port design which localizes the gas delivery into the gap between the fast coil and the anode, by a pre-ionizer ringing circuit connected to the fast coil, and by a bias field means which optimally adjusts the plasma formation position in the ion beam source.
Abstract:
A microwave ion source comprising a discharge chamber provided with an ion source seed material inlet and an ion outlet, a means for radiating microwaves in said discharge chamber, a means for applying a magnetic filed to the inside of said discharge chamber, a means for supplying ion source seed material to said discharge chamber through said ion source seed material inlet and an ion extraction electrode, said ion extraction electrode being made of magnetic material having a resistivity of less than 10.sup.6 .OMEGA.cm and a permeability of more than 5. The present microwave ion source has an improved ion current efficiency.
Abstract:
A reservoir containing a material to be ionized has in its bottom a capillary extending outwardly in symmetrical with the optical axis of an ion source, and has a needle extending coaxially through said capillary in said reservoir so that the apex end of the needle projects slightly beyond the exterior surface of the reservoir. Intensive electric field at the apex end of the needle is formed by an extracting electrode disposed in facing the needle. An electric current is supplied through conductive wires or filaments supporting the reservoir for heating the reservoir. As a result, the liquid material to be ionized in the reservoir seeps smoothly through the capillary of the reservoir toward the apex end of the needle for field evaporation and ionization.