Development of Wideband Terahertz Emission Spectroscopy by using heterodyne receiver

利用外差接收器开发宽带太赫兹发射光谱

基本信息

批准号：
17550020
负责人：
OZEKI Hiroyuki
金额：
$ 2.18万
依托单位：
Toho University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

项目摘要

The purpose of this study is to develop gas-phase emission spectroscopy at terahertz region by using heterodyne detection technique. The method has a capability of taking a wideband frequency spectra (1000-4000 MHz) without degrading frequency accuracy obtained in the conventional absorption spectroscopy (100 kHz or less). We demonstrated the following three points in order to demonstrate these advantages; 1. Spectroscopic measurements of pressure-broadened spectra to discuss its shape and derive pressure broadening or shift parameters. 2. Easy assignments of transitions of the molecule showing a complicated spectral pattern, and 3. Multiple or simultaneous quantum states observation. The experimental setup used in the present study is a superconducting receiver system at JAXA in Tsukuba Space Center operated at 0.6 THzFirst, we have succeeded to measure emission spectra of J=1-0 rotational transition of the two isotopomers of the hydrogen chloride molecule in the pressure range betwee … More n 0.3 to 200 hPa. Pressure broadening and pressure shift parameters against nitrogen and oxygen for the molecule can be derived by analyzing the shape of the observed emission spectra. The same kind of measurements was also conducted for the acetonitrile molecule, which is considered to be important in the tropospheric chemistry. Reliable pressure broadening and shift parameters will contribute to retrieve abundance of the molecule from the observed atmospheric spectra by remote sensing techniqueWe have also tried to detect emission spectra from the plasma obtained by discharging a mixture of the acetonitrile molecule and helium. The hydrogen cyanide, one of the reaction products produced by a discharge, is observed with its vibrational excited state. Our method makes it possible to estimate of the vibrtional temperature of the molecule to be approximately 410 K. This kind of information will contribute to kinetic study of the molecules.These results will be published in the Journal of Molecular Spectroscopy. Less

这项研究的目的是通过使用异差检测技术在Terahertz区域开发气相发射光谱。该方法具有接收宽带频率光谱（1000-4000 MHz）的能力，而无需在常规吸收光谱（100 kHz或更少）中获得的频率精度降解。我们证明了以下三点以证明这些优势。 1。对压力的光谱进行光谱测量，以讨论其形状并得出压力扩大或移位参数。 2。分子的过渡易于分配，显示出复杂的光谱模式，3。多个或简单的量子状态观察。演讲研究中使用的实验设置是在Tsukuba太空中心Jaxa的超导接收器系统，我们成功地测量了J = 1-0 j = 1-0旋转旋转过渡的发射光谱的两个同位素的旋转过渡器，这两个同位素的氯化物分子在压力范围内的氯化物分子中的压力范围较高。可以通过分析观察到的发射光谱的形状来得出针对氮和氧的压力扩大和压力移位参数。还针对乙腈分子进行了相同的测量，该分子在对流层化学中被认为很重要。可靠的压力扩大和移位参数将有助于通过远程灵敏度技术从观察到的大气光谱中获取分子的抽象，也试图通过排放乙腈分子和氦气的混合物来检测从等离子体中的发射光谱。氰化氢是由放电产生的反应产物之一，其振动激发态被观察到。我们的方法使估计分子的振动温度约为410K。这种信息将有助于分子的动力学研究。这些结果将发表在《分子光谱学杂志》上。较少的