Microwave and Optical Technology Letters, Jan 28, 2014
ABSTRACT Transmission lines of various degrees of dispersion are often designed and fabricated fo... more ABSTRACT Transmission lines of various degrees of dispersion are often designed and fabricated for use in high speed circuits and in metamaterials. The quick generation of dispersion diagrams and attenuation coefficient curves can be made from S-parameter measurements, with S21 alone being sufficient for generating dispersion diagrams. S21 is also sufficient to accurately measure the attenuation coefficient, group velocity, phase velocity and effective index of refraction of highly dispersive transmission lines.
A procedure for the attachment of superconducting electronic chip devices to their housing was ne... more A procedure for the attachment of superconducting electronic chip devices to their housing was needed for experiments on the nonlinear response of superconducting devices to high frequency currents. Candidate methods include atmospheric gas low temperature indium soldering, inert gas indium soldering, and conductive epoxy film. All three processes were developed using visual quality and procedural complexity as the basis for judging process quality. Epoxy film is the simplest and resulted in the most uniform attachment. Low temperature solder is more complicated, especially in an inert gas, but the chips are re-usable and may experience less contamination. Currently, evaluation is focusing on device performance. To evaluate the electrical performance of attached chips, nonlinearity is induced inside the passband of Tl2Ba2CaCu2O8 and YBa2Cu3O7 superconducting resonators. Nonlinear emission is stimulated locally in the vicinity of a probe by off-resonance, low frequency signals. By mixing of two very low frequency local currents and of one current in the passband, 2nd and 3rd order intermodulation distortion is generated around the resonant frequency, permitting the quantitative determination of the currents associated with each order of nonlinearity. This technique is also being used to perform spatially resolved nonlinearity studies, to examine the effect of doping on nonlinearity in Tl2Ba2CaCu2O8, and to search for a correlation between lithographic edge quality and 2nd and 3rd order nonlinearity
A procedure for the attachment of superconducting electronic chip devices to their housing was ne... more A procedure for the attachment of superconducting electronic chip devices to their housing was needed for experiments on the nonlinear response of superconducting devices to high frequency currents. Candidate methods include atmospheric gas low temperature indium soldering, inert gas indium soldering, and conductive epoxy film. All three processes were developed using visual quality and procedural complexity as the basis for judging process quality. Epoxy film is the simplest and resulted in the most uniform attachment. Low temperature solder is more complicated, especially in an inert gas, but the chips are re-usable and may experience less contamination. Currently, evaluation is focusing on device performance. To evaluate the electrical performance of attached chips, nonlinearity is induced inside the passband of Tl2Ba2CaCu2O8 and YBa2Cu3O7 superconducting resonators. Nonlinear emission is stimulated locally in the vicinity of a probe by off-resonance, low frequency signals. By mixing of two very low frequency local currents and of one current in the passband, 2nd and 3rd order intermodulation distortion is generated around the resonant frequency, permitting the quantitative determination of the currents associated with each order of nonlinearity. This technique is also being used to perform spatially resolved nonlinearity studies, to examine the effect of doping on nonlinearity in Tl2Ba2CaCu2O8, and to search for a correlation between lithographic edge quality and 2nd and 3rd order nonlinearity
ABSTRACT Transmission lines of various degrees of dispersion are often designed and fabricated fo... more ABSTRACT Transmission lines of various degrees of dispersion are often designed and fabricated for use in high speed circuits and in metamaterials. The quick generation of dispersion diagrams and attenuation coefficient curves can be made from S-parameter measurements, with S21 alone being sufficient for generating dispersion diagrams. S21 is also sufficient to accurately measure the attenuation coefficient, group velocity, phase velocity and effective index of refraction of highly dispersive transmission lines.
Over the past 15 years, Hope College has been producing hydrogen and helium ion beams with an Alp... more Over the past 15 years, Hope College has been producing hydrogen and helium ion beams with an Alphatross® ion source and 5SDH Pelletron® tandem Van de Graaff accelerator. The manufacturer stated the possibility of creating nitrogen ions from this source, but Hope College has not, up until now, attempted to do so. By mixing approximately 1% nitrogen into hydrogen source gas, imidogen (NH-) and amidogen (NH2-) ions are created and accelerated through the tandem accelerator. Oxygen and hydroxide beams are also present due to residual water vapor in the source after maintenance. Post acceleration, these ion beams were directed into a scattering chamber by a dipole bending magnet for identification. Alternate beams such as these open up new possibilities for future experiments such as nitrogen implantation.
Microwave and Optical Technology Letters, Jan 28, 2014
ABSTRACT Transmission lines of various degrees of dispersion are often designed and fabricated fo... more ABSTRACT Transmission lines of various degrees of dispersion are often designed and fabricated for use in high speed circuits and in metamaterials. The quick generation of dispersion diagrams and attenuation coefficient curves can be made from S-parameter measurements, with S21 alone being sufficient for generating dispersion diagrams. S21 is also sufficient to accurately measure the attenuation coefficient, group velocity, phase velocity and effective index of refraction of highly dispersive transmission lines.
A procedure for the attachment of superconducting electronic chip devices to their housing was ne... more A procedure for the attachment of superconducting electronic chip devices to their housing was needed for experiments on the nonlinear response of superconducting devices to high frequency currents. Candidate methods include atmospheric gas low temperature indium soldering, inert gas indium soldering, and conductive epoxy film. All three processes were developed using visual quality and procedural complexity as the basis for judging process quality. Epoxy film is the simplest and resulted in the most uniform attachment. Low temperature solder is more complicated, especially in an inert gas, but the chips are re-usable and may experience less contamination. Currently, evaluation is focusing on device performance. To evaluate the electrical performance of attached chips, nonlinearity is induced inside the passband of Tl2Ba2CaCu2O8 and YBa2Cu3O7 superconducting resonators. Nonlinear emission is stimulated locally in the vicinity of a probe by off-resonance, low frequency signals. By mixing of two very low frequency local currents and of one current in the passband, 2nd and 3rd order intermodulation distortion is generated around the resonant frequency, permitting the quantitative determination of the currents associated with each order of nonlinearity. This technique is also being used to perform spatially resolved nonlinearity studies, to examine the effect of doping on nonlinearity in Tl2Ba2CaCu2O8, and to search for a correlation between lithographic edge quality and 2nd and 3rd order nonlinearity
A procedure for the attachment of superconducting electronic chip devices to their housing was ne... more A procedure for the attachment of superconducting electronic chip devices to their housing was needed for experiments on the nonlinear response of superconducting devices to high frequency currents. Candidate methods include atmospheric gas low temperature indium soldering, inert gas indium soldering, and conductive epoxy film. All three processes were developed using visual quality and procedural complexity as the basis for judging process quality. Epoxy film is the simplest and resulted in the most uniform attachment. Low temperature solder is more complicated, especially in an inert gas, but the chips are re-usable and may experience less contamination. Currently, evaluation is focusing on device performance. To evaluate the electrical performance of attached chips, nonlinearity is induced inside the passband of Tl2Ba2CaCu2O8 and YBa2Cu3O7 superconducting resonators. Nonlinear emission is stimulated locally in the vicinity of a probe by off-resonance, low frequency signals. By mixing of two very low frequency local currents and of one current in the passband, 2nd and 3rd order intermodulation distortion is generated around the resonant frequency, permitting the quantitative determination of the currents associated with each order of nonlinearity. This technique is also being used to perform spatially resolved nonlinearity studies, to examine the effect of doping on nonlinearity in Tl2Ba2CaCu2O8, and to search for a correlation between lithographic edge quality and 2nd and 3rd order nonlinearity
ABSTRACT Transmission lines of various degrees of dispersion are often designed and fabricated fo... more ABSTRACT Transmission lines of various degrees of dispersion are often designed and fabricated for use in high speed circuits and in metamaterials. The quick generation of dispersion diagrams and attenuation coefficient curves can be made from S-parameter measurements, with S21 alone being sufficient for generating dispersion diagrams. S21 is also sufficient to accurately measure the attenuation coefficient, group velocity, phase velocity and effective index of refraction of highly dispersive transmission lines.
Over the past 15 years, Hope College has been producing hydrogen and helium ion beams with an Alp... more Over the past 15 years, Hope College has been producing hydrogen and helium ion beams with an Alphatross® ion source and 5SDH Pelletron® tandem Van de Graaff accelerator. The manufacturer stated the possibility of creating nitrogen ions from this source, but Hope College has not, up until now, attempted to do so. By mixing approximately 1% nitrogen into hydrogen source gas, imidogen (NH-) and amidogen (NH2-) ions are created and accelerated through the tandem accelerator. Oxygen and hydroxide beams are also present due to residual water vapor in the source after maintenance. Post acceleration, these ion beams were directed into a scattering chamber by a dipole bending magnet for identification. Alternate beams such as these open up new possibilities for future experiments such as nitrogen implantation.
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