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.

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 在95 GHz，Eldor在缓慢翻滚/接近刚性极限下的实验证明，即使在B1为15g的情况下，也可以照射整个频谱，尽管效率会降低。增加可用的B1将改善信噪比并提高数据收集的效率。实现这一目标的一个有希望的方法是使用介质加载的法布里-P？罗谐振器。对于直径等于自由空间波长，介电常数为4的介质棒，对应于毫米波长的石英，可以证明，如果将介质棒的光束强度和总能量归一化为在自由空间中传输的相同强度和总能量的高斯光束的光束强度和总能量，那么在自由空间场值上，介质棒中的B1场大约大5倍。换句话说，介质棒谐振器可以显著提高样品的可用B1，而不是其等效的自由空间。与自由空间谐振器相比，介质棒的存在对毫米波场也有显著的局部化效应，这对于尺寸有限的样品是一个优势。我们正在探索如何将介质棒谐振器集成到适用于高功率脉冲工作的实用法布里-P？罗谐振器中。钱德勒的早期论文对适用于介质棒谐振器的耦合方案提出了有用的建议。这种谐振器的概念也可能在170 GHz和240 GHz的低功率脉冲工作中找到应用，我们正在探索这种可能性，以期研究生物样品中的饱和，例如在低温下的血红素铁。