McPherson products

The Model 642 soft x-ray source is a compact, convenient to operate source for the 2keV to 50eV region. The unique dual-output of equivalent beams make it a useful source for many comparative applications in addition to wavelength calibration and so on. The two output beams originate from two views of the single emitting spot where the electron beam from the single hairpin filament collides with the interchangeable anode. The emitting spot is about 1mm diameter and depends on the source’s operating conditions.

The Model 629 Hollow Cathode is a CW gas discharge source used to ionize molecular or rare gases. It operates with no window and is a rich source of ion lines at wavelengths longer than 25 nm (less than 50 eV). Output line emission depends on the gases used. It is possible to mix or switch gases during operation. It is electrically quiet and features a water cooled anode and cathode. A differential pumping accessory is available to limit the gas load into the spectrometer. Commercial grade gases are generally used and selection may depend on your application. The source body has a port for directly monitoring gas pressure in the discharge. The Model 629 is a flexible source system for vacuum ultraviolet (VUV) wavelength calibration, ultraviolet photoemission spectroscopy (UPS) and other extreme UV spectroscopy applications. Source operation requires a 2 kV 500 mA current regulated power supply like the McPherson Model 730.

The Model 634 Deuterium lamp features a Magnesium Fluoride window, 1mm diameter emitting plasma and ~f/6 output. The source system includes cables, lamp housing and a power supply for lamp operation. This source is useful for vacuum ultraviolet (UV) and deep UV operation. Output between 380 and 165nm is continuous; below 165nm, molecular lines predominate. Because the sealing window is polished Magnesium Fluoride, cut with its optical axis perpendicular to its face, the source works to wavelengths as short as 115 nanometers. The Model 634 Deuterium lamp is available as a calibrated standard of spectral radiance. The calibrated Deuterium source comes with complete documentation. Source emission is measured every nanometer from 115 to 400nm.

Mercury calibration lamps are small, rugged, and easy to use. Because the lamps operate at low pressure, well spaced, intrinsically narrow and bright Mercury emission lines dominate the output spectrum. Background between the lines is very low. The output wavelengths are known exactly and are ideal for spectral calibration. Single lines are easily isolated with optical filters for alignment or other applications. Closely spaced lines are very useful for testing the resolution of dispersive instruments. Mercury spectral calibration lamps make excellent high intensity short wave UV sources too. About 90% of the total output is in the 253.65nm emission line. Appropriate UV eye safety measures are required. The visible lines are intense and useful for calibration of McPherson spectrometers.

The Model 621 modular light source operates with a variety of light sources: tungsten, Xenon and IR emitters. It is a complete system with forced air cooling, lamp mount module, housing, condenser, power supply and cables. The Model 621 mounts directly on the 5-inch diameter entrance slit of any McPherson spectrometer and may be adapted to other spectrometers or for standalone operation. Easy access to the housing interior and simplifies lamp and socket exchange. Adjusters for focus and alignment are externally accessible. Safety interlocks prevent shock hazard while power is applied. Forced air cooling, compartment reflectors and airflow baffling insures even heat removal from the system. This optimizes the sources stability and longevity.

The Model 618 Tungsten-Halogen Light Source produces an intense continuum from below 380nm and extending into the near infrared region of the spectrum. It uses a pair of plano-convex lenses to focus the filament at the entrance slit. This compact, forced air cooled source is capable of operating at apertures as fast as f/2 (when ordered with a monochromator, f/no matching apertures or lenses are included.

The water-cooled and (optionally) gas purged housing is for spectroscopy in the infrared. Water cooling removes heat and allows the emitter to reach its full potential and optimal lifetime. The cool housing also provides good contrast and has no light leaks or air turbulence. It is for use with the 22-Watt Ceramic element (similar to a high irradiance Nernst element). This is a convenient economical source with sufficient radiant output and is a good match for spectrometer slits. The housing is compact for light collection faster than f/2 if necessary. This lamp housing may be mounted directly to a spectrometer entrance slit and fits to our reflective condensers, chopper and filter wheel accessories. It is useful for better contrast in IR spectroscopy and for sources requiring to be operated in vacuum.

The Model 272 monochromator contains a large, 100-mm diameter diffraction grating. This guarantees a large solid angle of light collection. The gratings corrected design reduces optical aberrations. This improves the spectral resolution of this high throughput optical system. The Model 272 is a versatile research grade monochromator. It delivers high throughput and moderate spectral resolution. Usable in any attitude, standard features of much larger McPherson monochromators have found home in this high efficiency f/2 monochromator. An example of a Model 272 in use for cathodoluminesce (CL) imaging and spectroscopy of geologic materials is described on the National Museum of Natural Histories, Department of Mineral Sciences web page

The Model 275D is a dedicated double grating monochromator providing additive or subtractive dispersion. The 275D compact housing contains the scanning mechanism and mechanical linkage of one precision wavelength sine drive for two gratings. Wavelength control is via the 789A-3 digital scan control with a single motor.The optically and mechanically coupled modified Seya-Namioka systems are equipped with aberration corrected concave holographic gratings. Spectrally agile, the model 275D features all first surface optics for the best UV-Vis-NIR response. Double monochromators are used for a variety of applications that require extremely low levels of scattered or stray light.

The Model 303 is a 250mm focal length f/4 prism monochromator with good throughput. It is built like a Czerny-Turner and uses a prism in Littrow configuration for refraction. Prisms do not have multiple orders like diffraction gratings and are capable of very low dispersion. The 303 monochromator used with slits works as a tunable filter, or cut filter for UV-Raman applications. Used with a wide exit slit (or by removing the exit slit) the focal plane accepts an imaging CCD or infra-red bolometer array (for example).