Submillimeter-Wave(400-700 GHz) Sources and Spectroscopy of the H_2D^+Ion

我们用毫米波速调管和非线性混频器(砷化镓肖特基二极管)组合构成倍频和三倍频，目的是获得400-700 GHz的辐射功率，适合于H_2D离子的亚毫米波跃迁光谱。然而，由构建的三倍频产生的输出功率太低，无法在亚毫米波区域进行光谱分析。我们已设法改进倍增器，以提供更高的输出功率。我们计划在未来一年推出一台输出频率在400 GHz以上的四倍频激光器。我们利用高灵敏度的毫米波和亚毫米波光谱仪与本研究项目开发的乘法器相结合，研究了几种暂态分子，特别是潜在的星际分子候选者。我们主要根据实验室的光谱结果，确定了四个新的星际分子：CH2CN(^2B_1)、环-C_3H(^2B_2)、CP(^2SIGMA^)和C_4Si。我们还研究了一些新的分子，如PS(2pi_R)、MGS、CaS、ALS(^2SIGMA)。FeS(^5DELTA_I)、NH_2O(^2B_1)、ND_2(^2B_2)和His(^2A‘)，并高精度地测定了它们的详细分子常数。

We constructed doublers and triplers from a combination of millimeter wave klystrons and nonlinear mixers (GaAs Schottky diode), aiming to obtain the radiation power at 400-700 GHz suitable for spectroscopy of the submillimeter-wave transitions of the H_2D^+ion. However, the output power generated from the tripler constructed was too low in power to carry out spectroscopy in the submillimeter-wave region. We have tried to improve the tripler to give a higher output power. A quadrupler giving the output power in the frequency region above 400 GHz is planned in the coming year.We have studied several transient molecules, especially potential candidates for interstellar molecules by using the high-sensitivity millimeter and submillimeter-wave spectrometer combined with the multipliers developed in the Research Project.. We identified four new interstellar molecules, CH_2CN(^2B_1), cyclic-C_3H(^2B_2), CP(^2SIGMA^+), and C_4Si, mainly on the basis of the laboratory spectroscopic results. We also studied several new molecules such as PS(2PI_r), MgS, CaS, AlS(^2SIGMA^+). FeS(^5DELTA_i), NH_2O(^2B_1), ND_2(^2B_2), and HSiS(^2A'), and determined their detailed molecular constants with high precision.