Double monochromator camera

The optics of angular dispersive small angle scattering cameras differ according to the field of application. Thus the double monochromator camera is mainly used for anomalous dispersion experiments (Fig. 21) By varying the Bragg angle of two... 

Fig. 17a. Double monochromator camera for SAXS studies. The orientation of the reflecting planes is schematically indicated, b. Single monochromator camera for SAXS studies, c. Four-crystal monochromator setup...

In Raman measurements [57], the 514-nm line of an Ar+ laser, the 325-nm line of a He-Cd laser, and the 244-nm line of an intracavity frequency-doubled Ar+ laser were employed. The incident laser beam was directed onto the sample surface under the back-scattering geometry, and the samples were kept at room temperature. In the 514-nm excitation, the scattered light was collected and dispersed in a SPEX 1403 double monochromator and detected with a photomultiplier. The laser output power was 300 mW. In the 325- and 244-nm excitations, the scattered light was collected with fused silica optics and was analyzed with a UV-enhanced CCD camera, using a Renishaw micro-Raman system 1000 spectrometer modified for use at 325 and 244 nm, respectively. A laser output of 10 mW was used, which resulted in an incident power at the sample of approximately 1.5 mW. The spectral resolution was approximately 2 cm k That no photoalteration of the samples occurred during the UV laser irradiation was ensured by confirming that the visible Raman spectra were unaltered after the UV Raman measurements. 

In the case of the sulphur triimide S(NBu-f)3, the dispersive Raman technique applying a double monochromator and a CCD camera was employed to obtain the information from polarized measurements (solution studies) and also to obtain high-resolution spectra by low-temperature measurements. In the case of the main group metal complex, only FT-Raman studies with long-wavenumber excitation were successful, since visible-light excitation caused strong fluorescence. The FT-Raman spectra of the tetraimidosulphate residue were similar to those obtained from excitation with visible laser lines. 

Hg. 21. Schematic design of a double monochromator small-angle scattering camera. The first monochromator is at 24 m from the source. I denotes two ionization chambers. No focussing elements are used... 

Double focussing, mirror-monochromator cameras are optimized for maximum flux at the sample. This type of camera is hence mainly used for real time diffraction studies on biological samples and polymers (see Sect. 4). Such a camera is shown in Fig. 23. The first optical element could only be placed at 20 m... 

Fig. 23. Schematic design of a double focussing mirror-monochromator camera at DORIS The middle of the mirror is at 20 m from the source point. A bent, triangular monochromator crystal is used for horizontal focussing and a segmented mirror (quartz) for vertical focussing. The ionization chamber is designated by-I-...

Abbr. U undulator M mirror Mo monochromator D-Mo double monochromator Mu multilayers A aperture slits G guard slits S sample D detector. The length scale is determined by the insertion of the camera into the experimental hall, The different length of the mirror/ monochromator camera is due to the horizontal deflection by 20 as 27° (X 1.5 A)... 

The SERS measurements in the visible spectral range were obtained using a triple monochromator unit MOLE S 3000 (Instruments S.A./Jobin Yvon). The spectrometer consists of a double monochromator DHR 320 (600 grooves/mm), a main monochromator HR 640 (600 or 1800 grooves/mm), a diode array detector (E-IRY 1024), and a microscope (Olympus BH 2) with CCD camera and monitor. The microscope focuses the radiation of the laser (488 and 514 nm model 2020-03 Ar ion laser 633 nm model 127 HeNe laser, both Spectra-Physics) onto the sample giving a spatial resolution of 1 /im. The spectral solution is 8 1/cm. 

In Munich, we have developed our spectrometer around a Jarrell-Ash double monochromator equipped with holographic gratings, using photomultiplier detection [48-51]. An extracavity multiple-reflection cell [49] as well as intracavity excitation with transfer of the Raman-scattered light with optical fibres [50,51] were applied for signal enhancement. The multiple reflection cell has been transferred to Florence and installed at a Jobin-Yvon UlOOO spectrometer equipped with a charge-coupled device (CCD) camera [52]. 

Double immunofluorescence labeling in conjunction with microwave heating can be used to visualize two markers at the same cellular location in routine formalin-fixed and paraffin-embedded tissue sections (Mason et al 2000). The primary antibodies are either monoclonal antibodies of differing isotype/subclass or antibodies from different species. Labeling is visualized on a conventional fluorescence microscope equipped with a cooled analog monochrome CCD camera (Model C 5985, Hamamatsu Photonics, Billerica, MA) and recorded using off the shelf personal computer hardware and software. Contrary to general belief, paraffin-embedded tissue sections do not show excessive nonspecific fluorescence. 

The Biology Department beam line includes a station for protein crystallography (with Supper oscillation camera and FAST TV diffractometer) and a station for small angle diffraction (with a three-circle goniostat and MWPC electronic area detector). The latter station may be available for optimised anomalous dispersion crystallographic studies. The optical design for each consists of a bent pre-mirror, double crystal monochromator and bent post-mirror the mirrors have rhodium coatings (Wise and Schoenborn 1982). 

Participating research teams Naval Research Laboratory At the NSLS a large number of participating research teams (PRTs) have established beam lines on the NSLS and a number of instruments use diffractometers as well as oscillation cameras. One of these, for instance, is the Naval Research Laboratory (NRL) and National Bureau of Standards PRT as part of this effort, NRL is constructing a materials analysis X-ray beam line. The beam optics design consists of a platinum coated copper pre-mirror dynamically bent to approximate a parabolic cylinder, followed by a fixed-exit double crystal monochromator and a platinum coated fused silica cylinder bent to approximate an ellipsoid. The hutch contains a six-circle diffractometer (Kirkland, Nagel and Cowan 1983). 

UV resonance Raman spectra were obtained using a Renishaw Raman System 1000 by exciting with a frequency doubled Ar -laser, operating at 244 tun (40984 cm ). The photons scattered by the sample where dispersed by the monochromator and simultaneously collected on an UV-enhanced CCD camera. The collection optic was a x40 objective. A laser output of 12 mW was used, which resulted in a maximum incident power at the sample of approximately 2 mW. An exposure time of 240 s per spectrum was used. 

A typical experimental arrangement for Raman microscopy is shown in Fig. 3.25. The output beam of an argon laser or a dye laser is focused by a microscope objective into the microsample. The backscattered Raman light is imaged onto the entrance slit of a double or triple monochromator, which effectively supresses scattered laser light. A CCD camera at the exit of the monochromator records the wanted spectral range of the Raman radiation [364, 368, 369],... 

The recent availability of inexpensive Q"Switched frequency-doubled diode-pumped Nd YAG lasers may encourage more study of coherent Raman effects. Stimulated Raman spectroscopy (SRS) is especially easy to observe [13]. Only the laser, a short-focal-length monochromator and a spectrograph are needed. Because the stimulated effect is strong, an interline transfer CCD video camera and frame grabber can serve as the detector system. With this simple apparatus (Fig. 6), Grant and Hartwick observed the stimulated Raman spectra of common organic solvents, such as benzene and acetonitrile. The second Stokes shift for benzene is shown in Fig. 7. Stokes shifts up to the fourth are observable. 

---