95 GHZ SPECTROMETER CW LOCK-IN DEMODULATOR UPGRADE

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 我们的Acert 95 GHz连续波光谱仪以前使用了单个锁定放大器(SRS510)来检测光谱线型。我们目前正在将这个子系统升级到基于数字信号处理器(DSP)的锁定系统(Stanford Research Systems 850)，它比以前的设备提供了许多显著的性能优势。与传统的模拟锁定相比，基于DSP的单元具有更高的动态储备、更低的漂移、更低的失真和显著更高的相位分辨率。此外，由于该装置的内置显示和处理能力，数据可能会以一系列操作上有用的格式呈现给实验者，这是以前的锁定系统无法提供的。数字信号处理器单元的图形显示还将促进调频开发工作和宽线样品的调频检测的设置和分析。 将新的DSP锁定放大器集成到95 GHz光谱仪中，并将其I/O功能实现到光谱仪控制系统的例程中，需要对控制系统软件进行适度的修改。因此，在用新的DSP系统取代以前的锁定之前，正在编写新的Python脚本例程。当新的程序完成和调试后，我们将转移光谱仪的C.W.线路检测方案从其现有的模拟锁相检测器到DSP锁相。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Continuous-wave spectroscopy with our ACERT 95 GHz instrument has previously utilized a single lock-in amplifier (SRS 510) for detection of the spectral lineshape. We are presently upgrading this subsystem to a digital signal processor (DSP) based lock-in (Stanford Research Systems 850) which offers a number of significant performance advantages over the previous unit. The DSP-based unit has higher dynamic reserve, lower drift, lower distortion and dramatically higher phase resolution than the conventional analog lock-in it is replacing. Additionally, due to the unit's built-in display and processing capabilities, data may be presented to the experimentalist in a range of operationally-useful formats unavailable with the previous lock-in system. The DSP unit graphical display will also facilitate setup and analysis of frequency-modulation detection for FM development work and for broad-line specimens. Integration of the new DSP lock-in amplifier into the 95 GHz spectrometer and implementation of its I/O functions into routines of the spectrometer control system requires modest revision of the control system software. Accordingly, new Python scripting routines are being written prior to replacing the former lock-in with the new DSP system. When the new routines are completed and debugged, we will transfer the spectrometer's c.w. line detection scheme from its existing analog lock-in detector to the DSP lock-in.