A NOVEL SOFT X-RAY MICROSCOPE FOR BIOMEDICAL USE

SOFT X-RAY MICROSCOPY IS A PROMISING MICROIMAGING TECHNIQUE WHICH IS CURRENTLY UNDERGOING A SIGNIFICANT WORLDWIDE DEVELOPMENT EFORT. THE OBJECTIVE IS TO DEMONSTRATE BIOLOGICAL IMAGES WITH A NEW TYPE OF SOFT X-RAY MICROSCOPE OF A NOVEL AND VERY SIMPLE DESIGN. THE GEOMETRY OF THE MICROSCOPE IS VERY SIMILAR TO THE FIELD EMISSION MICROSCOPE. INSTEAD OF USING A SOLID EMITTER, THE INSTRUMENT USES A SPECIAL CONE-LIKE, HOLLOW EMITTER. THE SPECIMEN TO BE EXAMINED IS PLACED INSIDE THE EMITTER TIP. SOFT X-RAYS ARE BEAMED THROUGH THE SPECIMEN AND ONTO THE HEMISPHERICAL EMITTER TIP MEMRANE. THE TIP MEMBRANE IS TRANSPARENT TO X-RAYS AND IS COATED WITH A HIGH EFFICIENCY PHOTOEMITTER. PHOTOELECTRONS ARE LIBERATED INTO THE VACUUM, OUTSIDE THE EMITTER TIP, IN A PATTERN CORRESPONDING TO THE X-RAY ABSORPTION OF THE SPECIMEN (CONTACT IMAGE). THE PHOTOELECTRONS ARE ACCELERATED RADIALLY TO A DETECTOR BY A HIGH VOLTAGE ON THE EMITTER. A MAGNIFIED, HIGH RESOLUTION, REAL-TIME IMAGE RESULTS. THIS INSTRUMENT HAS THE POTENTIAL FOR VALUABLE USE IN BIOMEDICINE. SPECIMENS CAN REMAIN WET, UNSTAINED, AND UNSECTIONED. THIS TECHNOLOGY HAS ALREADY BEEN DEMONSTRATED WITH HARDER X-RAYS. PHASE I RESEARCH WILL ADDRESS THE MORE DEMANDING TECHNOLOGY NEEDED FOR UTILIZING THE DESIRED ULTRASOFT X-RAYS AND BIOLOGICAL SPECIMENS.