DIELECTRIC ROD RESONATOR AT HIGH FREQUENCIES

高频介质棒谐振器

• 批准号: 8363956
• 负责人: KEITH A EARLE
• 金额: $ 0.14万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8363956
• 关键词: Caliber; Coupling; Data Collection; Frequencies; Funding; Goals; Grant; Heme Iron; Methods; National Center for Research Resources; Noise; Paper; Physiologic pulse; Principal Investigator; Quartz; Research; Research Infrastructure; Resources; Sampling; Scheme; Signal Transduction; Source; Suggestion; Technology; United States National Institutes of Health; Work; cold temperature; cost; improved; millimeter; research study; retinal rods

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. At 95GHz, ELDOR experiments in the slow tumbling/near rigid limit have demonstrated that even with a B1 of 15G, it is possible to irradiate the entire spectrum, although with reduced efficiency. Increasing the available B1 would improve the signal to noise and increase the efficiency of data collection. One promising method of accomplishing this goal is by the use of a dielectric-loaded Fabry-P¿rot resonator. For a dielectric rod of diameter equal to the free space wavelength and dielectric constant 4, corresponding to quartz at millimeter wavelengths, one can show that if one normalizes the dielectric rod beam intensity and total energy to that of a gaussian beam propagating in free space with the same intensity and total energy, then the B1 field is larger by approximately a factor of 5 in the dielectric rod over the free space field value. In other words, a dielectric rod resonator can significantly enhance the available B1 at a sample compared to its free space equivalent. The presence of the dielectric rod also has a significant localization effect on the millimeter wave field, compared to a free-space resonator, which is an advantage for size limited samples. We are exploring how to integrate the dielectric rod resonator into a practical Fabry-P¿rot resonator suitable for high power pulse work. The early paper by Chandler has useful suggestions for coupling schemes appropriate to a dielectric rod resonator. This resonator concept may also find applications in low power pulse work at 170 and 240GHz, and we are exploring this possibility with a view towards studying saturation in bio-samples, such as heme irons, at low temperatures.

该子项目是利用资源的众多研究子项目之一 由 NIH/NCRR 资助的中心拨款提供 该子项目的主要支持。 并且子项目的首席研究员可能是由其他来源提供的， 包括其他 NIH 来源的子项目可能列出的总成本。 代表子项目使用的中心基础设施的估计数量， NCRR 赠款不直接向子项目或子项目工作人员提供资金。 在 95GHz 处，慢速翻滚/接近刚性极限的 ELDOR 实验表明，即使 B1 为 15G，也可以辐射整个频谱，尽管增加可用的 B1 会提高信噪比并提高发射功率。实现这一目标的一种有前途的方法是使用电介质加载的 Fabry-P¿对于相当于自由空间波长和介电常数 4 的介电棒，直径为毫米波长的石英，可以证明，如果将介电棒光束强度和总能量归一化为传播的高斯光束的强度和总能量。自由空间具有相同的强度和总能量，则介质棒中的 B1 场比自由空间场值大大约 5 倍。换句话说，介质棒谐振器可以。与自由空间等效物相比，样品处的可用 B1 显着增强。与自由空间谐振器相比，介电棒的存在对毫米波场也具有显着的局域效应，这对于尺寸有限的样品来说是一个优势。我们正在探索如何将介质棒谐振器集成到实用的 Fabry-P¿适合高功率脉冲工作的 rot 谐振器。 Chandler 的早期论文对适合介质棒谐振器的耦合方案提出了有用的建议，这种谐振器概念也可能在 170 和 240GHz 的低功率脉冲工作中得到应用，我们正在探索这种可能性。旨在研究低温下生物样品（例如血红素铁）的饱和度。