Why in News?
- Researchers have successfully modified a standard X-ray Photoelectron Spectroscopy (XPS) machine to operate at atmospheric pressure using rocket engine technology, potentially eliminating the need for massive synchrotron facilities.

XPS & The “De Laval” Innovation
- What is XPS? A tool used to study materials at the atomic level (e.g., batteries, catalysts). It shoots X-rays at a surface and measures the electrons that bounce off to identify elements and chemical bonds.
- The “Pressure Gap” Problem:
- Vacuum Requirement: Standard XPS needs a vacuum because air molecules block electrons from reaching the detector.
- The Limitation: Real-world reactions (like rust forming or car exhausts) happen at normal air pressure (1 atm), not in a vacuum.
- The Innovation (De Laval Nozzle):
- Researchers used a De Laval nozzle (technology used in rocket engines) to shoot a focused, supersonic jet of gas at the sample.
- Localized Pressure: This creates a tiny zone of high pressure (1 atm) right on the sample surface, while keeping the rest of the machine in a vacuum to protect the detectors.
- How it Works: The high-pressure gas layer is extremely thin (only 20 micrometers). This is thin enough for electrons to pass through and reach the detector, allowing scientists to “see” the surface chemistry even under pressure.
- Significance:
- Democratization: Scientists can now study real-world chemical reactions in their own standard labs instead of traveling to rare, stadium-sized synchrotrons.
- Applications: Will help in developing better industrial catalysts, longer-lasting batteries, and understanding corrosion in real time.

