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Electron Probe Micro-Analysis (EPMA)
About Instrument and its applications-
EPMA works by bombarding a micro-volume of a sample with a focused electron beam (typical energy = 5-30 KeV) and collecting the X-ray photons thereby emitted by the various elemental species. Because the wavelengths of these X-rays are characteristic of the emitting species, the sample composition can be easily identified by recording WDS spectra (Wavelength Dispersive Spectroscopy). WDS spectrometers are based on the Bragg's law and use various moveable, shaped mono crystals as mono chromators.
  • EPMA is a fully qualitative and quantitative method of non-destructive elemental analysis of micron-sized volumes at the surface of materials, with sensitivity at the level of ppm. Routine quantification to 1% reproducibility is obtained over several days. It is the most precise and accurate micro-analysis technique available and all elements from B to U and above can be analyzed.
  • EPMA is fully compatible with routine analysis sessions, with easy and direct interpretation of the results.
  • EPMA instruments are equipped with a complete kit of built-in microscopy tools that allow simultaneous X-ray (WDS), SEM and BSE imaging, plus sophisticated visible light optics; they provide very flexible sample inspection with image magnification ranging from 40 to 400,000.
Major applications are found in geochemistry, mineralogy, geochronology, physical metallurgy, and nuclear metallurgy, materials science including glass, ceramics, superconductors, cements, microelectronics, and biochemistry. EPMA provides much better results than standard SEM/EDS systems. Because of the internal properties of WDS, the general sensitivity, analysis of light elements and risks of erroneous interpretation of qualitative spectra are all superior with EPMA. Spectral resolution and detector dead time are much better than EDS (Energy Dispersive Spectroscopy). The excitation beam regulation system and sophisticated sample stage capabilities guarantee that this technique provides outstanding stability and measurement repeatability.
General Information-
Model- SX100
Year of Installation- 2009
  • Accelerating Voltage:    0.2 to 40 kV
  • Beam Current:        10-5 to 10-12 A
  • Beam Diameter:    0.6µm at 15kV and 100nA
  • WDS:        4 No. WDS with crystal LiF, PET, TAP, PC0 (2d=4.5nm), PC1 (2d=6nm), PC2        (2d=9.5nm)
  • Spectrometer range (0.22 to 0.83) sin theta with a resolution of 10-5 sin-theta.
  • Electron Gun: Tungsten Filament
  • SEM Image Magnification: 150X to 400,000X
  • BSE Image: Spatial resolution 0.1 atomic number unit at Z 29.
  • Sample Stage: Stage movement for X axis= 50mm, Y-axis = 80mm  and Z axis=1.5mm with a resolution of  0.1µm.
Sample Requirements-
Solid (Sample Thickness < 1cm)
Analytical Charges-
For Charges Information Click Below Link-
Procedure for Sample Submission-
For users of IIT Roorkee Only
Internal candidates have to first register themselves at following portal-
Obtain a Token ID after logging in to above portal and then submit application (which can be downloaded from below link) mentioning the token ID, registration no. along with other relevant details to the IIC office.
For Downloading application click here-
For users other than IIT Roorkee
The Application (duly forwarded by concerned department HOD/Guide) along with analytical charges (in the form of Demand Draft) mentioning all the relevant parameters related to analysis may be sent to the below mentioned address-
Institute Instrumentation Centre
Indian Institute of Technology Roorkee
Mode of Payment:
For users of IIT Roorkee Only
The payment may be made in advance (In Cash) at Institute Instrumentation Centre Office.
For users other than IIT Roorkee
The payment should be made in the form of a Demand Draft in favor of “Dean SRIC, IIT Roorkee”. The DD should be sent along with your application and Samples.
NOTE: The DD amount should include service tax as per GOI rules.
Department of Earth Sciences
Contact Person
Mr. Ravindra Saini
Technical Officer
Office Tel: +91-1332-286292