Abstract: A method for determining the shape and size of particles and their constituent elements is disclosed. Particle ions are accelerated through a mass spectrometer useful in identifying the source particle of the resulting ions. By measuring the time-varying intensity of the identified ions as they strike a detector, a plot of the intensity of the ions over time is obtained for each ionized particle. The size of each ionized particle is determined by measuring a time span corresponding to the width of the peak of this plot. If the detector is a phosphor detector, the shape of the particle may be determined by using a high-speed camera to capture cross-section images of the ion-induced light pattern at closely-spaced successive moments in time. Alternatively, the intensity of ions striking the detector along at least one lateral dimension may be detected.

Abstract: Fiber is drawn from a preform comprising a silica body, e.g., a sol-gel derived overcladding or substrate tube. Prior to sintering, the body is treated with a gaseous mixture containing one or more non-oxygenated sulfur halides, to remove and/or reduce the size of refractory oxide particles, and/or dehydroxylate the body. Removal of metal oxide particles or reduction in their size contributes to drawing of optical fiber exhibiting desirable strength, since such particles act as initiation sites for breakage. Advantageously, the halides include sulfur chlorides, which provide desirable improvements compared to treatment by oxygenated sulfur chlorides such as thionyl chloride (SOCl2).

Abstract: A method for determining the shape and size of particles and their constituent elements is disclosed. Particle ions are accelerated through a mass spectrometer useful in identifying the source particle of the resulting ions. By measuring the time-varying intensity of the identified ions as they strike a detector, a plot of the intensity of the ions over time is obtained for each ionized particle. The size of each ionized particle is determined by measuring a time span corresponding to the width of the peak of this plot. If the detector is a phosphor detector, the shape of the particle may be determined by using a high-speed camera to capture cross-section images of the ion-induced light pattern at closely-spaced successive moments in time. Alternatively, the intensity of ions striking the detector along at least one lateral dimension may be detected.

Abstract: An apparatus and method that prevents a damaging movement—in any plane—between fiber ends within a connector assembly, where a damaging movement is a movement of the fiber ends with the connector assembly which may give rise to a damaging thermal event while an optical power source is generating a high-optical-power-density signal that is propagated through the fibers. A prevention mechanism is integral to the connector precludes damaging movement. The prevention mechanism includes a) a locking mechanism that precludes any damaging movement while engaged and b) an indication generator that upon being engaged or disengaged generates an indication that can be used to control the on/off state of the optical power source.

Abstract: Fiber is drawn from a preform comprising a silica body, e.g., a sol-gel derived overcladding or substrate tube. Prior to sintering, the body is treated with a gaseous mixture containing one or more non-oxygenated sulfur halides, to remove and/or reduce the size of refractory oxide particles, and/or dehydroxylate the body. Removal of metal oxide particles or reduction in their size contributes to drawing of optical fiber exhibiting desirable strength, since such particles act as initiation sites for breakage. Advantageously, the halides include sulfur chlorides, which provide desirable improvements compared to treatment by oxygenated sulfur chlorides such as thionyl chloride (SOCl2).

Abstract: Fiber is drawn from a preform comprising a silica body, e.g., a sol-gel derived overcladding or substrate tube. Prior to sintering, the body is treated with a gaseous mixture containing one or more non-oxygenated sulfur halides, to remove and/or reduce the size of refractory oxide particles, and/or dehydroxylate the body. Removal of metal oxide particles or reduction in their size contributes to drawing of optical fiber exhibiting desirable strength, since such particles act as initiation sites for breakage. Advantageously, the halides include sulfur chlorides, which provide desirable improvements compared to treatment by oxygenated sulfur chlorides such as thionyl chloride (SOCl2).

Abstract: A small sample of a refractory material, e.g., about 0.1 g to about 10 g, is heated to at least 1000° C., generally under a pressure of less than about 10−5 Torr. Evolved hydrogen-containing gases and/or carbon-containing gases are monitored, e.g., by mass spectrometry, and, based on the amount of the evolved gases, the concentration of hydrogen and/or carbon in the sample is calculated. It is therefore possible to accurately determine the hydrogen and carbon concentration from a small sample of a material, by a process much less burdensome than conventional techniques.

Abstract: A calibration sample for a particle analyzer comprises a deposition tube containing a known distribution of submicron size particles. The sample is produced using a microwave discharge in a microwave chamber to generate particles from a feedstock gas at subambient pressure, transporting the particles downstream from the microwave chamber and depositing them on the tube. The downstream tubing can then be removed, stored, transported and used as a calibration sample. In subsequent use, gas flowing through the tube entrains particles from the inner wall, producing a particle-laden gas whose particle size distribution and composition are identical to that produced originally--even after storage for months. The sample, requiring no special equipment, can be used at remote sites to prove-in and calibrate particle analyzers.

Abstract: The present invention provides methods and apparatus for analyzing the particulate contents of a sample such that a high proportion of the sample particles are analyzed without discrimination against high electronegativity and high ionization potential elements. In an exemplary embodiment, the invention comprises an apparatus for analyzing the particulate content of a sample having particulate diameters in the range of 0.001-10 microns. The apparatus comprises an evacuable chamber equipped with a chamber entrance through which a particle-laden gas stream enters. An inlet device, such as a capillary, communicates with the chamber entrance for inputting the particle-laden gas stream to the evacuable chamber. A laser is positioned to produce a focused laser beam which intersect the particle-laden gas stream at position approximately 0.1 mm from the chamber entrance. The laser beam has a power density sufficient to fragment and ionize particles entrained within the particle-laden gas stream.