RАМ-30μ
X-ray analytical microprobe microscope
- X-ray fluorescence microanalyzer with X-ray probe size from 30 to 1000 µm
- Elemental micromapping from 11Na to 92U
- Sample stage positioning accuracy 10 µm
- Transmission radiography
- Unique research methodologies
TECHNICAL DESCRIPTION
Purpose
The X-ray fluorescence microanalyzer "RAM-30μ" is intended for the study of objects using local elemental microanalysis with the possibility of micromapping, transmission radiography and optical microscopy. The elements from 11Na to 92U are analyzed simultaneously.
Features
- Microfocus X-ray tube
- Polycapillary lens for forming a variable-size X-ray probe
- Energy dispersive semiconductor detector for local elemental analysis
- Set of primary radiation filters
- Video camera for analysis area selection
- Optical digital microscope for detailed study of analysis area
- Automated two-coordinate sample stage for object positioning and scanning over a specified sample area (X, Y coordinates)
- Analytical unit movement in vertical direction
- Pumping out of the measurement chamber for analysis of light elements
- Specialized software for radiography studies, local elemental analysis and elemental mapping
X-ray optical scheme
The source of primary X-ray radiation is a microfocus X-ray tube (1). On the tube exit window, a collimator is mounted, which limits the solid angle of the X-ray radiation divergence. Below, a disk with replaceable filters is located (2).
The X-ray beam is formed by a polycapillary lens (3). The sample is mounted on the sample stage (5) either in the focus of the polycapillary lens (maximum spatial resolution) or behind the lens focus in the diverging part of the X-ray beam – depending on the spatial requirements of the analysis. The sample stage automatically moves along the X and Y axes, and the measurement system – along the Z axis.
A video camera (7) with an objective lens (6) that provides image magnification of up to 200x (digital microscope) displays an image of the sample on the computer monitor. On this image, an area for analysis is selected with the computer mouse.
X-ray fluorescence spectra detection is carried out by a semiconductor drift energy-dispersive detector (8).
To register transmission radiography images, a photodiode detector is used (9). It measures the intensity of radiation that passed through the sample at the point of analysis and thus determines the sample density at the corresponding point.
The digital microscope objective lens, the polycapillary lens and the energy-dispersive detector are located in a sealed chamber. To measure light elements, it is possible to pump out air from this chamber with a compact fore-vacuum pump to improve sensitivity.
The window of the vacuum chamber which is used for analysis of the sample fluorescence is covered with a piece of PET film. The analyzed area of the sample is positioned at a minimum distance from the PET chamber window in order to minimize the loss of the low-energy part of the X-ray fluorescence spectrum.
Delivery package
The base package includes:
- Spectrometer (analytical unit)
- Software for working with the spectrometer
- Set of test samples
- Set of spare tools and accessories
- Set of sample holders
Additional options:
- Vacuum system
- Computer
- Printer
- Additional sample holders
TECHNICAL CHARACTERISTICS
| Maximum rating of X-ray tube power supply | Ua up to 45 kV; Ia up to 12 mA; P up to 500 VA |
| X-ray tube anode material | Mo |
| X-ray tube primary radiation filtering parameters |
Automatic installation and change of 10 filters:
|
| X-ray probe diameter | 30 — 1000 µm |
| Sample stage positioning accuracy | 10 µm |
| Spectral information measurement channels |
|
| Energy range | 1 — 40 keV |
| Detector energy resolution | < 130 eV (on the Mn Kα line) |
| Measurement chamber atmosphere |
|
| Maximum size of scanned area | 150×150 mm |
| Maximum sample height | 130 mm |
| Maximum sample weight | 10 kg |
| Radiation safety | The instrument is freed from radiation control in accordance with corresponding certificate |
| Analytical unit dimensions (L×W×H) | 665×615×650 mm |
| Analytical unit weight | 85 kg |
| Power consumption (220 V) |
Without fore-vacuum pump – up to 800 W With fore-vacuum pump – up to 1300 W |
MAIN SOFTWARE FUNCTIONS
| Instrument control |
|
| Elemental mapping |
|
| Base of standard samples |
|
| Qualitative analysis |
|
| Spectrum processing |
|
| Spectrum comparison |
|
| Methods of quantitative analysis |
|
| Matrix effects evaluation | Available |
| Package processing of multiple spectra | Available |
| Creation of reports on measurement results | Available |
| Recalculation of measurement results on compounds | Available |
| Spectrum search |
|
MAIN ANALYTICAL AND METROLOGICAL PARAMETERS
| Range of analyzed elements | 11Na (Kα) — 92U (Lα) |
| Spectral range | 1 — 40 keV |
| Energy resolution | < 130 eV (on the Mn Kα line) |
| Maximum concentration of analyzed elements | 100% |
| Minimum concentration of analyzed elements | From 0.001% (depends on the matrix) |
| Long-term stability of the analyzer (relative standard deviation of the output signal) | Less than 1% |
| Inherent instrument error | Less than 1% |
SOFTWARE DESCRIPTION
The software provides the ability to manage the instrument, control the measurement process and analyze the acquired spectral information, as well as to carry out additional measurements. Various implemented modes of the software make control of the instrument easy, and provide the ability to obtain complete spectral information and display it in the most convenient way.
The software interface is divided into three user parts: measurement mode, mapping mode and expert mode.
Measurement mode
In this mode, the positions of the sample stage and the measurement chamber are set.
Also, the main measurement parameters are defined: current and voltage of the X-ray tube, exposure time, the necessary primary radiation filter, and turning on the fore-vacuum pump.
Using a video camera or an optical microscope, the analysis area on the sample is selected and also the desired resolution is set.
The measurement mode makes it possible to make measurements of standard samples, which are used to build calibration graphs for quantitative analysis.
Also in the measurement mode, alignment, calibration of the energy scale and metrological verification of the instrument are carried out.
Mapping mode
In the mapping mode, all the acquired spectral information is processed: radiography images and element distribution maps are built.
For element maps and radiography images, it is possible to change color, brightness and gradient level, as well as to display scale and comments. The element maps can be used for getting additional information: one can calculate the distribution of the number of points by intensities, plot the changes in intensities along a line, and measure sizes of various regions. The element maps can be overlaid on one another, as well as onto the radiography image and also the image from the video camera. Measurement of additional spectra with automatic redirection into the measurement mode is possible.
One can view the spectrum at each point of an element distribution map and also sum the spectra over the whole measurement area or over a specified region. The spectra in such cases automatically open in the expert mode where processing of the spectral data is carried out.
Expert mode
This mode is intended for processing of the acquired spectra.
The spectra acquired using the measurement mode can be mathematically processed in various ways. When carrying out qualitative analysis (which is possible in automatic mode), the lines of elements are marked with chemical symbols. When doing so, the escape peaks and double peaks are taken into account.
Spectra can be compared with each other, subtracted, added and averaged. The search for measured spectra that are most similar to the current one is also possible. The background component is modeled in various ways to increase the accuracy of the analysis.
For quantitative analysis, several calculation methods are available: linear regression, the Lucas-Tooth method with and without alpha correction, and the standard-background method based on incoherently scattered radiation measurements. Additionally, the methodology editor is provided which makes it possible to create custom formulas for calculating concentrations which take into account errors in standard samples for individual elements. In the absence of standard samples, the standardless method of fundamental parameters can be used.
The developed analysis methodologies are saved for serial measurements. The methodologies include all measurement parameters, selected standard samples, formulas for calculating concentrations including ones that take into account errors in standard samples for individual elements, and also some other parameters.
Using package processing of spectra, fast processing of similar spectra in the same way is possible.
The expert mode also includes functions for recalculating measurement results onto compounds, calculating detection limits, editing the base of standard samples and other auxiliary functions.
The results of measurement processing and calculation of concentrations can be output in the form of custom reports.
SOFTWARE FEATURES
The measurement mode makes it possible to carry out:
- control of the main instrument components
- metrological verification of the instrument
- energy scale calibration
- setting measurement parameters: current and voltage of the X-ray tube, exposure time, installation of primary filters and use of vacuum, if necessary
- control of the sample stage and measurement chamber movement
- selection of the analysis area by means of the video camera or optical microscope
Visualization of spectral information for elemental mapping and radiography studies includes:
- display of element distribution maps and the radiography image for the selected surface area
- overlaying of element distribution maps, and the radiography and optical images of the analyzed area onto one another
- digital control of brightness and contrast
- image scale adjustment
- measurement of distances between image points
- labeling and text printing on images
- storing of images in a database
- recording digitized images to external media
- printing of images and protocols
Algorithms and programs for mathematical processing and modeling of spectra and background include:
- qualitative analysis (possible in automatic mode)
- comparison, subtraction and averaging of spectra
- various methods for modeling spectra and background
- taking into account escape peaks and double peaks
- semiquantitative analysis by means of the fundamental parameters method (standardless)
- quantitative methods for calculating concentrations: linear regression, the Lucas-Tooth method with and without alpha correction, the standard-background method based on incoherently scattered radiation measurements
- methodology editor with the ability to create custom formulas and take into account errors in standard samples for individual elements
- creation of automatic measurement methodologies with a full description of measurement parameters, mathematical processing of spectra and calculation options
- ability to add software modules to solve specific problems (specialized analysis methodologies, identification, sorting, grading, etc.)
- comparison of spectra and search for an analogue in the spectral library