The MSA-130 is a compact double monochromator with enhanced functionality and low stray light. The key feature of the MSA-130 is its unique ability to operate in both dispersion additive and subtractive dispersion modes.
DOUBLE MONOCHROMATOR FOR EXCELLENT STRAY LIGHT REJECTION
MULTIFUNCTIONAL: ADDITIVE/DUAL DISPERSION & NON-ADDITIVE/SUBTRACTIVE DISPERSION
COMPACT & COST-EFFECTIVE
The MSA-130 is a compact double monochromator with enhanced functionality and low stray light.
The key feature of the MSA-130 is its unique ability to operate in both dispersion additive and subtractive dispersion modes.
The MSA-130 operation modes are changed over by manual switching of a two-position selector switch from the position “Addition” to “Subtraction” and vice versa without any additional alignment by the user. The instrument is multifunctional, compact, easy-to-use and reliable.
In the Additive Dispersion Mode MSA-130 operates as a standard double additive monochromator (effective focal length is 260 nm) with extremely low stray light provided by its intermediate slit.
In the Subtractive Dispersion Mode MSA-130 operates as a tunable filter with adjustable band pass and sharp edge. A width of selected spectral range is set by the intermediate slit, and the central wavelength is set by synchronous turning of two identical diffraction gratings.
Since in the Subtractive Dispersion mode the beam path in the second half of the double monochromator conforms completely to the reverse beam path in the first half; the result is the full compensation of dispersions, and the zero dispersion is achieved. The whole spectrum selected by the intermediate slit is imaged at the second monochromator’s output as a spatial line.
The MSA-130 is equipped with choice of ruled gratings to suit the application. To ensure perfect dispersion compensation (zero dispersion), the manufacturer takes special care that diffraction gratings of both monochromator halves were replicas made of the same matrix.
The MSA-130 entrance, intermediate and exit slits have manual control and smooth micrometrical adjustment of the opening width. Entrance and exit slits are placed at an angle of 66° to the vertical.
Both the MSA-130 gratings are located at the same axis and are driven by the same step motor. This allows ensuring complete synchronism of gratings’ rotation and high precision of wavelength setting. The MSA-130 gratings are computer controlled via the USB interface.
In terms of design, the gratings are fixed in one holder, which is carefully aligned by our service-engineers. The holder with a working set of gratings is installed into the device. At your choice, the MSA-130 may be supplied with one or more additional sets of gratings in holders.
Replacement of diffraction gratings in the MSA-130 is easy and fast (see the figure).
To replace gratings it is enough to open a cover at the MSA-130 rear panel, unscrew two mounting screws and withdraw the holder with gratings. The holder is placed into a special box from the Spare Parts Kit. A new set of gratings is installed into the MSA-130 housing and fixed with two screws. This procedure is sufficient to perfectly reproduce the position of gratings corresponding to the manufacturer’s calibration.
The MSA-130 delivery set includes a viewing unit Sight, which is used to check the current monochromator calibration by the user. The Sight contains an achromatic objective; it is placed on the entrance slit and is used to visually observe positions of the known spectral lines relative to the centre of exit slit. The spectral range of the Sight operation is 200nm-2000nm.
The software of the MSA-130 monochromator provides possibility of real-time correction of factory calibration by the user.
The software also allows calculating the line width selected by the MSA-130 in the Additive Dispersion and Subtractive Dispersion modes depending on the set width of entrance, intermediate and exit slits.
The MSA-130 exit slit contains two mounting holes M2.5 that allow fixing your own detector to the slit housing, if necessary. Two additional holes M3 are located on the housing close to the slit unit. Location of mounting holes is shown in the figure.
Note: To avoid a breakdown of the slit mechanism it is prohibited to fix any units weighing more than 1kg to the slit housing!