摘要:
A Czochralski process (“CZ”) crystal growth method and furnace having a heater capable of generating a heating zone, a crucible within the heating zone and capable of retaining a volume of molten crystal growth material forming a melt line oriented in a designated position within the heating zone, a seed growth rod retractable from the crucible with a rod retraction mechanism, for forming a crystal boule thereon proximal the melt line from the molten crystal growth material. The furnace causes relative movement between the crucible and heating zone as the crystal boule is retracted, so that the melt line is maintained in the designated position within the heating zone. In some embodiments relative movement is based at least in part on sensed weight of the growing crystal boule. In other embodiments the crucible growth rod retraction mechanism are fixed relative to each other by a gantry.
摘要:
A Czochralski process (“CZ”) crystal growth method and furnace having a heater capable of generating a heating zone, a crucible within the heating zone and capable of retaining a volume of molten crystal growth material forming a melt line oriented in a designated position within the heating zone, a seed growth rod retractable from the crucible with a rod retraction mechanism, for forming a crystal boule thereon proximal the melt line from the molten crystal growth material. The furnace causes relative movement between the crucible and heating zone as the crystal boule is retracted, so that the melt line is maintained in the designated position within the heating zone. In some embodiments relative movement is based at least in part on sensed weight of the growing crystal boule. In other embodiments the crucible growth rod retraction mechanism are fixed relative to each other by a gantry.
摘要:
A lid for a crystal growth chamber crucible is constructed by forming arcuate sector-shaped portions and coupling them in abutting relationship, for example by welding, to form an annular profile fabricated lid. The arcuate sector-shaped portions may be formed and removed from a lid fabrication blank with less waste than when unitary annular lids are formed and removed from a similarly sized fabrication blank. For example, the sector-shaped portions may be arrayed in an undulating pattern on the fabrication sheet.
摘要:
A lid for a crystal growth chamber crucible is constructed by forming arcuate sector-shaped portions and coupling them in abutting relationship, for example by welding, to form an annular profile fabricated lid. The arcuate sector-shaped portions may be formed and removed from a lid fabrication blank with less waste than when unitary annular lids are formed and removed from a similarly sized fabrication blank. For example, the sector-shaped portions may be arrayed in an undulating pattern on the fabrication sheet.
摘要:
A method for fabricating a detector or light guide using laser technology. The method yields a detector component such as a scintillator, light guide or optical sensor which provides for the internal manipulation of light waves via the strategic formation of micro-voids to enhance control and collection of scintillation light, allowing for accurate decoding of the impinging radiation. The method uses laser technology to create micro-voids within a target media to optically segment the media. The micro-voids are positioned to define optical boundaries of the optically-segmented portions forming virtual resolution elements within the scintillator. Each micro-void is formed at its selected location using a laser source. The laser source generates and focuses a beam of light into the target media sequentially to form the micro-voids. The laser beam ablates the media at the focal point, thereby yielding the micro-void.
摘要:
A method of making LSO scintillators with high light yield and short decay times is disclosed. In one arrangement, the method includes codoping LSO with cerium and another dopant from the IIA or IIB group of the periodic table of elements. The doping levels are chosen to tune the decay time of scintillation pulse within a broader range (between about ˜30 ns up to about ˜50 ns) than reported in the literature, with improved light yield and uniformity. In another arrangement, relative concentrations of dopants are chosen to achieve the desired light yield and decay time while ensuring crystal growth stability.
摘要:
Medical imaging may be accomplished with a high photoconductive gain at a relatively low operating voltage by employing a black silicon photodetector and integrating CMOS components with elements of the photodetector.
摘要:
A method for precision cutting liquid soluble scintillator materials by an operator is disclosed, including the steps of providing a first run of a moving filament in operative proximity to cut the scintillator materials, concurrent with wetting at least the first run length of the moving filament with organic solvent, and engaging the wetted first run with the soluble scintillator materials for a time sufficient to create a kerf having cut surfaces with solvent thereon, with the kerf cut surfaces dissolved to reshape the kerf corners, and without the formation of surface hydrates. The wetting step is accompanied by providing a second run of the wetted filament in a reverse direction and engaging the scintillator materials. The first run and second run engaging steps are concurrent with tensioning the moving filament, producing kerfs through the scintillator materials, with organic solvent delivered onto kerf surfaces. The organic solvent, such as alcohol or organic-based solvent, dissolves the kerf surfaces and contiguous materials, softening the surfaces and producing precisely cut kerfs with gently radiused corners. Repetitive dicing, slitting, slotting and otherwise segmenting of the scintillator materials with the wetted moving filament creates precisely cut subunit scintillator materials with gently radiused corners. The method produces extremely precise kerfs in soluble scintillator materials with kerfs having gently radiused corners that are resistance to stress fractures, breakage, and cleavage during production and use of the scintillator materials.
摘要:
Disclosed are a method of growing a rare-earth oxyorthosilicate crystal and a crystal grown using the method. A melt is prepared by melting a first substance including at least one rare-earth element and a second substance including at least one element from group 7 of the periodic table. A seed crystal is brought into contact with the surface of the melt and withdrawn to grow the crystal.
摘要:
A method for producing a high resolution detector array so as to provide very high packing fraction, i.e. the distance between scintillator elements is minimized so the detector efficiency will be higher than is currently achievable. In the preferred embodiment of the present invention, the fabrication methodology is enhanced by handling LSO bars rather than single crystals when gluing on the Lumirror® as well as etching the LSO. Namely, an LSO boule is cut into wide bars of a selected dimension, for example 30 mm, which are then acid etched or mechanically polished. A selected number, N, of these LSO bars can then be glued together with Lumirror® sheets between each bar (coating the LSO disks and Lumirror® sheets with Epotek 301-2). The glued bar block is then cut again into bars in a perpendicular direction, and these new LSO-Lumirror® bars are etched. Finally, a selected number, M, of these LSO-Lumirror® bars are glued together with Lumirror® sheets between each bar; thus creating an etched N×M LSO-Lumirror® array, (where M may or may not be equal to N), without having to handle individual LSO crystals or small Lumirror® pieces.