X-ray microscope is an instrument that uses X-rays to image microscopic objects, which can magnify microstructures that cannot be distinguished by the naked eye for observation and research. It combines traditional CT technology with optical microscopy technology, converts X-ray signals into visible light signals through scintillators, and then uses optical systems and high-sensitivity, high-resolution CCD cameras to obtain digital images.
The imaging principle of X-ray microscope is basically the same as that of optical microscope, following the principles of geometric optics. The key component is the optical element that plays a role in imaging and magnification. Due to the short wavelength of X-rays, the refractive index at the interface between glass and general materials is close to 1. Therefore, glass lenses cannot be used, and zone plates are usually used as imaging magnification elements. In addition, it also utilizes absorption contrast and phase contrast imaging to detect X-rays through CCD and other surface detectors, thereby achieving imaging of microscopic objects.
Main structure
Light source: Commonly used are laboratory X-ray light sources, linear accelerators, and synchrotron radiation devices. Laboratory light sources such as high-power rotating anode X-ray tubes, fine focusing X-ray tubes, etc. have low brightness; Synchrotron radiation light sources are both nearly parallel and high-intensity, with adjustable wavelengths, making them an ideal light source.
Focusing element: commonly used multilayer reflective focusing mirrors and zone plates can reduce the size of the light spot and increase brightness. Capillary tubes can also serve as focusing elements, which change the direction of X-ray propagation based on the total reflection of X-rays on the inner wall of the capillary tube to achieve focusing.
Imaging magnifying element: generally a waveband plate, composed of two sets of concentric circular rings made of different materials arranged alternately, which can image and magnify X-rays.
Detector: including photosensitive film, image board, image intensifier, semiconductor detector (CCD), etc., used to detect X-rays passing through the sample and convert them into signals that can be recorded and analyzed.
Maintenance and upkeep:
Optical component maintenance
Lens cleaning: Use specialized lens cleaning paper and optical cleaner (such as xylene) to wipe the lens, avoiding direct hand touch or rough tools.
Oil mirror treatment: After use, it is necessary to promptly use wiping paper to absorb the medium oil, then clean and dry it with xylene.
Mechanical component maintenance
Handle with care: When carrying, hold the mirror arm with one hand and the mirror holder with the other hand to avoid vibration.
Regular inspection: tighten mechanical components and replace severely worn parts (such as rotary tables, lifting tables, etc.)