The advent of the Los Alamos National Laboratory Fourier Transform Spectroscopy Facility represents a break with past techniques for reducing Fourier transform data. In contrast to system dependent mainframe reduction packages, the LANL data reduction is performed exclusively on Apple MacIntosh II microcomputers. For scientists involved in Fourier transform spectroscopy there is a need for a unified data reduction package that will accomodate high resolution spectra from both the LANL FTS Facility and the McMath Fourier Transform Spectrometer at Kitt Peak. An adaptation of the Kitt Peak code DECOMP is presented that facilitates the reduction of spectral data from either laboratory on IBM PC-compatible computers.
洛斯阿拉莫斯国家实验室傅立叶变换光谱设备的出现代表了与过去减少傅立叶变换数据技术的突破。与依赖于系统的大型机缩减包相比，LANL数据缩减只在Apple MacIntosh II微型计算机上执行。对于参与傅里叶变换光谱的科学家来说，需要一个统一的数据缩减包，以适应来自LANL FTS设施和Kitt峰McMath傅里叶变换光谱仪的高分辨率光谱。基特峰代码DECOMP的改编，提出了有利于减少光谱数据从IBM pc兼容的计算机实验室。
{"title":"Digital Signal Processing of Fourier Transform Spectra on IBM PC-Compatible Computers","authors":"M. Abrams","doi":"10.1364/hrfts.1989.tub4","DOIUrl":"https://doi.org/10.1364/hrfts.1989.tub4","url":null,"abstract":"The advent of the Los Alamos National Laboratory Fourier Transform Spectroscopy Facility represents a break with past techniques for reducing Fourier transform data. In contrast to system dependent mainframe reduction packages, the LANL data reduction is performed exclusively on Apple MacIntosh II microcomputers. For scientists involved in Fourier transform spectroscopy there is a need for a unified data reduction package that will accomodate high resolution spectra from both the LANL FTS Facility and the McMath Fourier Transform Spectrometer at Kitt Peak. An adaptation of the Kitt Peak code DECOMP is presented that facilitates the reduction of spectral data from either laboratory on IBM PC-compatible computers.","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"161 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132467438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the early days of spectroscopy, arc sources were commonly used to obtain grating spectra of atoms and simple molecules. Since photographic detection was used, the poor stability of the arc was not a problem. Stability is a severe problem for the Fourier transform spectrometer and arcs are generally not suitable. The inductively coupled plasma (ICP), developed as a source for spectrochemical analysis, is similar in excitation to an arc, but is much cleaner and is relatively stable. Efforts have been made to exploit the ICP as a source of energetic spectra for the one meter McMath FTS of the National Solar Observatory at Kitt Peak.
{"title":"The ICP/FTS as a Source of High Resolution Atomic and Molecular Spectra","authors":"R. Engleman","doi":"10.1364/hrfts.1989.mb3","DOIUrl":"https://doi.org/10.1364/hrfts.1989.mb3","url":null,"abstract":"In the early days of spectroscopy, arc sources were commonly used to obtain grating spectra of atoms and simple molecules. Since photographic detection was used, the poor stability of the arc was not a problem. Stability is a severe problem for the Fourier transform spectrometer and arcs are generally not suitable. The inductively coupled plasma (ICP), developed as a source for spectrochemical analysis, is similar in excitation to an arc, but is much cleaner and is relatively stable. Efforts have been made to exploit the ICP as a source of energetic spectra for the one meter McMath FTS of the National Solar Observatory at Kitt Peak.","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"418 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133193360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
For many years the most extensive analyses of neutral chromium have been those of C.C.Kiess1,2. They represent results accumulated over a period of more than 30 years, dating back to the 1920’s. The energy levels in the compilation of Sugar and Corliss3 are mainly from this early work.
{"title":"Revised energy levels for neutral chromium","authors":"J. E. Murray","doi":"10.1364/hrfts.1992.thd3","DOIUrl":"https://doi.org/10.1364/hrfts.1992.thd3","url":null,"abstract":"For many years the most extensive analyses of neutral chromium have been those of C.C.Kiess1,2. They represent results accumulated over a period of more than 30 years, dating back to the 1920’s. The energy levels in the compilation of Sugar and Corliss3 are mainly from this early work.","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116070603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Spectral distortion due to the nonlinear response of HgCdTe detectors is well known. Methods for removing such features are discussed. Nonlinear response in HgCdTe detectors is a well known complication in midir Fourier transform spectroscopy; methods of removing the spectral artifacts created by nonlinearity are less well understood. While the instrument and experiment may be designed so that the desired spectrum is properly sampled, non-linearity introduces spectral features that lie outside the intended bandpass and consequently are undersampled and subject to aliasing. Consequently, in cases where nonlinear response may be expected it is essential that optical filters be chosen with the nonlinear harmonics in mind. Several examples of nonlinearity are considered, with practical examples drawn from the ATMOS data set.
{"title":"Detector nonlinearity in Fourier transform spectroscopy","authors":"M. Abrams","doi":"10.1364/hrfts.1992.saa6","DOIUrl":"https://doi.org/10.1364/hrfts.1992.saa6","url":null,"abstract":"Spectral distortion due to the nonlinear response of HgCdTe detectors is well known. Methods for removing such features are discussed.\u0000 Nonlinear response in HgCdTe detectors is a well known complication in midir Fourier transform spectroscopy; methods of removing the spectral artifacts created by nonlinearity are less well understood. While the instrument and experiment may be designed so that the desired spectrum is properly sampled, non-linearity introduces spectral features that lie outside the intended bandpass and consequently are undersampled and subject to aliasing. Consequently, in cases where nonlinear response may be expected it is essential that optical filters be chosen with the nonlinear harmonics in mind. Several examples of nonlinearity are considered, with practical examples drawn from the ATMOS data set.","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123446823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
High resolution absorption infrared spectroscopy is a largely used way to gather information on the chemical composition of the Earth atmosphere. The early pioneers (A. Adel, M. Migeotte,…), using large grating instruments, were able to recognize the vibration-rotation signatures of molecules like CH4, CO, NO, N2O … They showed how the Sun can be used as the necessary bright and stable light source.
高分辨率吸收红外光谱是收集地球大气化学成分信息的一种广泛使用的方法。早期的先驱(A. Adel, M. Migeotte，…)使用大型光栅仪器，能够识别像CH4, CO, NO, N2O这样的分子的振动旋转特征…他们展示了如何将太阳用作必要的明亮和稳定的光源。
{"title":"High Resolution Low Noise Atmospheric Spectroscopy","authors":"L. Delbouille","doi":"10.1364/hrfts.1992.sab1","DOIUrl":"https://doi.org/10.1364/hrfts.1992.sab1","url":null,"abstract":"High resolution absorption infrared spectroscopy is a largely used way to gather information on the chemical composition of the Earth atmosphere.\u0000 The early pioneers (A. Adel, M. Migeotte,…), using large grating instruments, were able to recognize the vibration-rotation signatures of molecules like CH4, CO, NO, N2O … They showed how the Sun can be used as the necessary bright and stable light source.","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123747606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An overview of our recent work with the Kitt Peak Fourier transform spectrometers will be presented. All of our laboratory spectra were recorded at the McMath interferometer. However, the infrared absorption spectrum of C3 was detected in atmosphere of a carbon star with the interferometer of the 4 meter telescope.
{"title":"Fourier Transform Spectroscopy of Transient Molecules","authors":"P. Bernath","doi":"10.1364/hrfts.1989.wb1","DOIUrl":"https://doi.org/10.1364/hrfts.1989.wb1","url":null,"abstract":"An overview of our recent work with the Kitt Peak Fourier transform spectrometers will be presented. All of our laboratory spectra were recorded at the McMath interferometer. However, the infrared absorption spectrum of C3 was detected in atmosphere of a carbon star with the interferometer of the 4 meter telescope.","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129946723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. McDowell, B. Krohn, B. Palmer, D. Hof, T. Manning, J. Winefordner
The Los Alamos Fourier transform spectrometer has been used to study the following four near-ultraviolet transitions of nitrogen molecules in a helium inductively-coupled plasma torch: N 2 + 1NG: B 2 Σ u + − X 2 Σ g + ( 0 − 0 ) and N22PG: C3Πu- B3Πg (0-2, 0-1, 0-0). Molecular constants for the N 2 + band have been determined using combination differences and polynomial fits, and will be compared with published values. These data demonstrate the usefulness of this instrument for molecular spectroscopy.
利用洛斯阿拉莫斯傅里叶变换光谱仪研究了氦电感耦合等离子体炬中氮分子的四种近紫外跃迁:n2 + 1NG: b2 Σ u +−x2 Σ g +(0−0)和N22PG: C3Πu- B3Πg(0- 2,0 - 1,0 -0)。n2 +带的分子常数已经用组合差分和多项式拟合确定，并将与已发表的值进行比较。这些数据证明了该仪器对分子光谱学的有用性。
{"title":"High-Resolution FT Spectroscopy of the Violet Transitions in the Nitrogen Molecular Ion N 2 +","authors":"R. McDowell, B. Krohn, B. Palmer, D. Hof, T. Manning, J. Winefordner","doi":"10.1364/hrfts.1989.tua5","DOIUrl":"https://doi.org/10.1364/hrfts.1989.tua5","url":null,"abstract":"The Los Alamos Fourier transform spectrometer has been used to study the following four near-ultraviolet transitions of nitrogen molecules in a helium inductively-coupled plasma torch:\u0000 \u0000 \u0000 \u0000 N\u0000 2\u0000 +\u0000 \u0000 \u0000 \u0000 \u0000 1NG: B\u0000 \u0000 2\u0000 \u0000 \u0000 Σ\u0000 u\u0000 +\u0000 \u0000 −\u0000 \u0000 X\u0000 2\u0000 \u0000 \u0000 Σ\u0000 g\u0000 +\u0000 \u0000 (\u0000 0\u0000 −\u0000 0\u0000 )\u0000 \u0000 \u0000 and N22PG: C3Πu- B3Πg (0-2, 0-1, 0-0). Molecular constants for the \u0000 \u0000 \u0000 \u0000 N\u0000 2\u0000 +\u0000 \u0000 \u0000 \u0000 band have been determined using combination differences and polynomial fits, and will be compared with published values. These data demonstrate the usefulness of this instrument for molecular spectroscopy.","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"76 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131190708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The simplest method for measuring atomic transition probabilities is a two step process requiring (1) the radiative lifetime of the upper level of the transition and (2) the branching fraction, the probability that the upper level decays via the particular transition of interest. This latter probability is found by measuring the relative intensity of all of the decay channels that contribute significantly to the total decay strength of the upper level.
{"title":"Atomic Transition Probability Measurements with the Kitt Peak 1-m. FTS*","authors":"W. Whaling, J. Brault","doi":"10.1364/hrfts.1989.tub6","DOIUrl":"https://doi.org/10.1364/hrfts.1989.tub6","url":null,"abstract":"The simplest method for measuring atomic transition probabilities is a two step process requiring (1) the radiative lifetime of the upper level of the transition and (2) the branching fraction, the probability that the upper level decays via the particular transition of interest. This latter probability is found by measuring the relative intensity of all of the decay channels that contribute significantly to the total decay strength of the upper level.","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"138 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122857232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A variety of time-resolved Fourier transform infrared (FTIR) techniques have been described in the literature.1–11 The basic concept is to trigger a transient event such as a chemical photolysis, for example with a lamp or a laser, and to acquire absorption or emission amplitudes with the Fourier transform interferometer at specific time delays after the triggering event. One method steps the mirror to a new fixed position and takes a time-resolved trace at each position. The difficulty with this method comes in the long-term instrument stability of the mirror position in this "step and stop" mode of operation.2–4 Another method allows the mirror to sweep rapidly and continuously, and data at a number of times after a single triggering event are collected as the mirror sweeps. The point in the interferogram where the trigger occurs is varied, so that data are obtained at all mirror positions and times. These data are then used to construct interferograms at a number of different time delays after the triggering event. This method has sometimes been found to have artifacts if there is Jitter in the sweep speed of the mirror or if the amplitude of the initiating source is not constant.5
{"title":"Pulsed Time-Resolved Fourier Transform Infrared Emission Spectroscopy","authors":"S. Leone, T. R. Fletcher, E. Woodbridge","doi":"10.1364/hrfts.1989.tua2","DOIUrl":"https://doi.org/10.1364/hrfts.1989.tua2","url":null,"abstract":"A variety of time-resolved Fourier transform infrared (FTIR) techniques have been described in the literature.1–11 The basic concept is to trigger a transient event such as a chemical photolysis, for example with a lamp or a laser, and to acquire absorption or emission amplitudes with the Fourier transform interferometer at specific time delays after the triggering event. One method steps the mirror to a new fixed position and takes a time-resolved trace at each position. The difficulty with this method comes in the long-term instrument stability of the mirror position in this \"step and stop\" mode of operation.2–4 Another method allows the mirror to sweep rapidly and continuously, and data at a number of times after a single triggering event are collected as the mirror sweeps. The point in the interferogram where the trigger occurs is varied, so that data are obtained at all mirror positions and times. These data are then used to construct interferograms at a number of different time delays after the triggering event. This method has sometimes been found to have artifacts if there is Jitter in the sweep speed of the mirror or if the amplitude of the initiating source is not constant.5","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129059350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jill Angus, T. Niemczyk, Larry Layman, B. Palmer, D. Hof
Electron densities and excitation or spectroscopic temperatures have been determined for an iron hollow cathode lamp containing Ar/N2 and Ne/N2 fill gas mixtures. The responses of both properties to current, total fill gas pressure and N2 partial pressures were monitored. Responses to variations in pressure and fill gas composition appear to demonstrate more than one mechanism for both excitation and current transport. Electron density is compared to literature values and found to be similar. Excitation temperatures are compared to previous work done in our laboratory and found to demonstrate the same trend.
{"title":"Electron Density and Excitation Temperature in an Iron Hollow Cathode Lamp","authors":"Jill Angus, T. Niemczyk, Larry Layman, B. Palmer, D. Hof","doi":"10.1364/hrfts.1989.pdp1","DOIUrl":"https://doi.org/10.1364/hrfts.1989.pdp1","url":null,"abstract":"Electron densities and excitation or spectroscopic temperatures have been determined for an iron hollow cathode lamp containing Ar/N2 and Ne/N2 fill gas mixtures. The responses of both properties to current, total fill gas pressure and N2 partial pressures were monitored. Responses to variations in pressure and fill gas composition appear to demonstrate more than one mechanism for both excitation and current transport. Electron density is compared to literature values and found to be similar. Excitation temperatures are compared to previous work done in our laboratory and found to demonstrate the same trend.","PeriodicalId":159025,"journal":{"name":"High Resolution Fourier Transform Spectroscopy","volume":"11235 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134027797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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