Abstract: An apparatus and method produce, from a Gaussian laser pulse, a sequence of laser rings having a spatiotemporal configuration such that impingement of the laser rings on a surface of a nuclear material in a target assembly produces constructively interfering shock waves that converge on a focal region of the nuclear material, thereby producing sufficient pressures and temperatures to form tritium in the focal region. The temporal and/or spatial intervals between the concentric pulsed laser rings are adjusted to substantially match propagation times of impingement from one ring to the next in a shock propagation layer of the target assembly. A second laser or neutron tube may be used to create a cavitation bubble at the focus. In addition to the shock waves generated in the plane of the surface, through-plane shock waves can be generated to increase the overall shock pressure.

Abstract: An adhesive composition made from an elastomer and a tackifying resin. The tackifying resin includes a farnesene polymer or copolymer having the following properties: i) less than 10 weight percent of volatile organic compounds; ii) Mn between 300 Da and 1000 Da; iii) Mw between 400 Da and 3000 Da; iv) Mw/Mn between 1.00 and 3.00; v) Tg between ?50° C. and 20° C.; and vi) viscosity between 400,000 cP and 1,000,000 cP at 25° C. A method of making the farnesene-based polymer or copolymer includes combining a farnesene monomer and a solvent and optionally adding one or more co-monomers selected from dienes, branched mono-olefins, and vinyl aromatics, to provide a monomer feed, and polymerizing the monomer feed by combining it with a Friedel-Crafts initiator in a vessel. The farnesene-based polymer or copolymer tackifier may be combined with one or more elastomers and one or more other tackifiers to form an adhesive composition.

Abstract: An adhesive composition made from an elastomer and a tackifying resin. The tackifying resin includes a farnesene polymer or copolymer having the following properties: i) less than 10 weight percent of volatile organic compounds; ii) Mn between 300 Da and 1000 Da; iii) Mw between 400 Da and 3000 Da; iv) Mw/Mn between 1.00 and 3.00; v) Tg between ?50° C. and 20° C.; and vi) viscosity between 400,000 cP and 1,000,000 cP at 25° C. A method of making the farnesene-based polymer or copolymer includes combining a farnesene monomer and a solvent and optionally adding one or more co-monomers selected from dienes, branched mono-olefins, and vinyl aromatics, to provide a monomer feed, and polymerizing the monomer feed by combining it with a Friedel-Crafts initiator in a vessel. The farnesene-based polymer or copolymer tackifier may be combined with one or more elastomers and one or more other tackifiers to form an adhesive composition.

Abstract: A nonlinear terahertz (THz) spectroscopy technique uses a sample illuminated by two THz pulses separately. The illumination generates two signals BA and BB, corresponding to the first and second THz pulse, respectively, after interaction with the sample. The interaction includes excitation of at least one ESR transition in the sample. The sample is also illuminated by the two THz pulses together, with an inter-pulse delay ?, generating a third signal BAB. A nonlinear signal BNL is then derived via BNL=BAB?BA?BB. This nonlinear signal BNL can be then processed (e.g., Fourier transform) to study the properties of the sample.

Abstract: A tackifying resin includes a farnesene-based polymer having monomeric units derived from a farnesene monomer and one or more optional comonomers selected from the group consisting of dienes, branched mono-olefins, and vinyl aromatics and has a softening point greater than or equal to 80 degrees Celsius. A method of making the farnesene-based polymer includes combining a farnesene monomer and a solvent and optionally adding one or more comonomers selected from the group consisting of dienes, branched mono-olefins, and vinyl aromatics, to provide a monomer feed, and polymerizing the monomer feed by combining the monomer feed with a Friedel-Crafts catalyst in a vessel. The tackifying resin may be combined with an elastomer to form a hot melt adhesive composition.

Abstract: Quality control of a periodic structure is performed using the damping rate of acoustic waves generated in the periodic structure. In this technique, an excitation light beam illuminates the first layer in the periodic structure to excite an acoustic wave. Possible irregularities in the periodic structure can scatter the acoustic wave, thereby increasing the damping rate of the acoustic wave. A sequence of probe light beams illuminates the periodic structure to measure the acoustic wave as a function of time to generated a temporal signal representing the damping rate of the acoustic signal. The acquired damping rate is employed to evaluate the quality of the periodic structure.

Abstract: A nonlinear terahertz (THz) spectroscopy technique uses a sample illuminated by two THz pulses separately. The illumination generates two signals BA and BB, corresponding to the first and second THz pulse, respectively, after interaction with the sample. The interaction includes excitation of at least one ESR transition in the sample. The sample is also illuminated by the two THz pulses together, with an inter-pulse delay ?, generating a third signal BAB. A nonlinear signal BNL is then derived via BNL=BAB?BA?BB. This nonlinear signal BNL can be then processed (e.g., Fourier transform) to study the properties of the sample.

Abstract: A tackifying resin includes a farnesene-based polymer having monomeric units derived from a farnesene monomer and one or more optional comonomers selected from the group consisting of dienes, branched mono-olefins, and vinyl aromatics and has a softening point greater than or equal to 80 degrees Celsius. A method of making the farnesene-based polymer includes combining a farnesene monomer and a solvent and optionally adding one or more comonomers selected from the group consisting of dienes, branched mono-olefins, and vinyl aromatics, to provide a monomer feed, and polymerizing the monomer feed by combining the monomer feed with a Friedel-Crafts catalyst in a vessel. The tackifying resin may be combined with an elastomer to form a hot melt adhesive composition.

Abstract: A tackifying resin includes a farnesene-based polymer having monomeric units derived from a farnesene monomer and one or more optional comonomers selected from the group consisting of dienes, branched mono-olefins, and vinyl aromatics and has a softening point greater than or equal to 80 degrees Celsius. A method of making the farnesene-based polymer includes combining a farnesene monomer and a solvent and optionally adding one or more comonomers selected from the group consisting of dienes, branched mono-olefins, and vinyl aromatics, to provide a monomer feed, and polymerizing the monomer feed by combining the monomer feed with a Friedel-Crafts catalyst in a vessel. The tackifying resin may be combined with an elastomer to form a hot melt adhesive composition.

Abstract: An apparatus for detecting electromagnetic radiation within a target frequency range is provided. The apparatus includes a substrate and one or more resonator structures disposed on the substrate. The substrate can be a dielectric or semiconductor material. Each of the one or more resonator structures has at least one dimension that is less than the wavelength of target electromagnetic radiation within the target frequency range, and each of the resonator structures includes at least two conductive structures separated by a spacing. Charge carriers are induced in the substrate near the spacing when the resonator structures are exposed to the target electromagnetic radiation. A measure of the change in conductivity of the substrate due to the induced charge carriers provides an indication of the presence of the target electromagnetic radiation.

Abstract: A nonlinear terahertz (THz) spectroscopy technique uses a sample illuminated by two THz pulses separately. The illumination generates two signals BA and BB, corresponding to the first and second THz pulse, respectively, after interaction with the sample. The interaction includes excitation of at least one ESR transition in the sample. The sample is also illuminated by the two THz pulses together, with an inter-pulse delay ?, generating a third signal BAB. A nonlinear signal BNL is then derived via BNL=BAB?BA?BB. This nonlinear signal BNL can be then processed (e.g., Fourier transform) to study the properties of the sample.

Abstract: Quality control of a periodic structure is performed using the damping rate of acoustic waves generated in the periodic structure. In this technique, an excitation light beam illuminates the first layer in the periodic structure to excite an acoustic wave. Possible irregularities in the periodic structure can scatter the acoustic wave, thereby increasing the damping rate of the acoustic wave. A sequence of probe light beams illuminates the periodic structure to measure the acoustic wave as a function of time to generated a temporal signal representing the damping rate of the acoustic signal. The acquired damping rate is employed to evaluate the quality of the periodic structure.

Abstract: A nonlinear terahertz (THz) spectroscopy technique uses a sample illuminated by two THz pulses separately. The illumination generates two signals BA and BB, corresponding to the first and second THz pulse, respectively, after interaction with the sample. The interaction includes excitation of at least one ESR transition in the sample. The sample is also illuminated by the two THz pulses together, with an inter-pulse delay ?, generating a third signal BAB. A nonlinear signal BNL is then derived via BNL=BAB?BA?BB. This nonlinear signal BNL can be then processed (e.g., Fourier transform) to study the properties of the sample.

Abstract: A radiation detection technique employs field enhancing structures and electroluminescent materials to converts incident Terahertz (THz) radiation into visible light and/or infrared light. In this technique, the field-enhancing structures, such as split ring resonators or micro-slits, enhances the electric field of incoming THz light within a local area, where the electroluminescent material is applied. The enhanced electric field then induces the electroluminescent material to emit visible and/or infrared light via electroluminescent process. A detector such as avalanche photodiode can detect and measure the emitted light. This technique allows cost-effective detection of THz radiation at room temperatures.

Abstract: An apparatus for detecting electromagnetic radiation within a target frequency range is provided. The apparatus includes a substrate and one or more resonator structures disposed on the substrate. The substrate can be a dielectric or semiconductor material. Each of the one or more resonator structures has at least one dimension that is less than the wavelength of target electromagnetic radiation within the target frequency range, and each of the resonator structures includes at least two conductive structures separated by a spacing. Charge carriers are induced in the substrate near the spacing when the resonator structures are exposed to the target electromagnetic radiation. A measure of the change in conductivity of the substrate due to the induced charge carriers provides an indication of the presence of the target electromagnetic radiation.

Abstract: A tackifying resin includes a farnesene-based polymer having monomeric units derived from a farnesene monomer and one or more optional comonomers selected from the group consisting of dienes, branched mono-olefins, and vinyl aromatics and has a softening point greater than or equal to 80 degrees Celsius. A method of making the farnesene-based polymer includes combining a farnesene monomer and a solvent and optionally adding one or more comonomers selected from the group consisting of dienes, branched mono-olefins, and vinyl aromatics, to provide a monomer feed, and polymerizing the monomer feed by combining the monomer feed with a Friedel-Crafts catalyst in a vessel. The tackifying resin may be combined with an elastomer to form a hot melt adhesive composition.

Abstract: A radiation detection technique employs field enhancing structures and electroluminescent materials to converts incident Terahertz (THz) radiation into visible light and/or infrared light. In this technique, the field-enhancing structures, such as split ring resonators or micro-slits, enhances the electric field of incoming THz light within a local area, where the electroluminescent material is applied. The enhanced electric field then induces the electroluminescent material to emit visible and/or infrared light via electroluminescent process. A detector such as avalanche photodiode can detect and measure the emitted light. This technique allows cost-effective detection of THz radiation at room temperatures.

Abstract: An apparatus for detecting electromagnetic radiation within a target frequency range is provided. The apparatus includes a substrate and one or more resonator structures disposed on the substrate. The substrate can be a dielectric or semiconductor material. Each of the one or more resonator structures has at least one dimension that is less than the wavelength of target electromagnetic radiation within the target frequency range, and each of the resonator structures includes at least two conductive structures separated by a spacing. Charge carriers are induced in the substrate near the spacing when the resonator structures are exposed to the target electromagnetic radiation. A measure of the change in conductivity of the substrate due to the induced charge carriers provides an indication of the presence of the target electromagnetic radiation.

Abstract: A farnesene polymer is provided having a glass transition temperature greater than zero degrees Celsius that is obtained by combining a farnesene monomer and a solvent and optionally adding one or more vinyl aromatic comonomers to provide a monomer feed and polymerizing the monomer feed with a Friedel-Crafts catalyst. The farnesene polymer may be included as a resin in a rubber composition for tire applications.

Abstract: An apparatus for detecting electromagnetic radiation within a target frequency range is provided. The apparatus includes a substrate and one or more resonator structures disposed on the substrate. The substrate can be a dielectric or semiconductor material. Each of the one or more resonator structures has at least one dimension that is less than the wavelength of target electromagnetic radiation within the target frequency range, and each of the resonator structures includes at least two conductive structures separated by a spacing. Charge carriers are induced in the substrate near the spacing when the resonator structures are exposed to the target electromagnetic radiation. A measure of the change in conductivity of the substrate due to the induced charge carriers provides an indication of the presence of the target electromagnetic radiation.