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active magnetic-field canceller keyword “active magnetic-field canceller”

An instrument that detects momentarily (ever) changing magnetic fields over a TEM and generates the anti-phase magnetic fields against the magnetic fields to cancel them.

external magnetic field keyword “external magnetic field ”

"External magnetic field(s)" are magnetic fields that affect an electron microscope from the outside. Measures to prevent an adverse influence of the external magnetic fields on the instrument performance are needed. The tolerable external magnetic field for the installation of the electron microscope is 1 mG or less. ==external disturbance (interference)

keyword “external disturbance (interference)”==

Noises from external electro-magnetic fields and external mechanical vibrations, which degrade the stability and performance of an electron microscope, are called "external disturbance (interference)."

pneumatic damper keyword “pneumatic damper ”

A mount that absorbs vibrations using pneumatic springs. The "pneumatic damper" is used for preventing vibrations of a TEM unit. 5. cryo-transfer holder keyword “cryo-transfer holder ” A specimen holder used for biological specimen observation in cryo-electron microscopy. A biological specimen on a microgrid is loaded on the specimen holder in the cryo-workstation under liquid nitrogen temperature. The holder is connected to a Dewar for Liq. N2 and the tip of the holder is maintained at the liquid-nitrogen temperature. When the holder is inserted into the electron-microscope column, the tip of the holder is exposed to the air (though in a short time), thus the holder incorporates a shutter to prevent frost deposition to the specimen. Related term cryo-electron microscopy 6. goniometer stage keyword “goniometer stage ” A stage that has a tilt mechanism. The "goniometer stage" is used for aligning the crystal orientation and for observing a specimen by tilting it with respect to the incident electron beam. 7. side-entry stage keyword “side-entry stage ” A specimen stage into which the specimen is inserted from the side of the polepiece of the objective lens. Compared with the top-entry stage, the "side-entry stage" has disadvantages of instability to vibrations and heat. However, in the case of this stage, a space above the specimen stage can be effectively used to add analytical functions (tools) and to achieve large tilt angles of the specimen. Thus, the side-entry stage is very useful in applications to materials science and tomography. Furthermore, the advantages of this stage include: a nano-sized beam is produced on the specimen with the use of the C-O lens, and a large take-off angle of an EDS detector is achieved. Therefore, the side-entry stage is suitable for analytical electron microscopy. Related term top-entry stage 8. magnetic-field leakage keyword “magnetic-field leakage ” "Magnetic-field leakage" is a phenomenon where magnetic fields are leaked in a space other than a necessary local space. The components of a TEM that consist of permanent magnets or electromagnets are designed to generate magnetic fields in a local space but magnetic-field leakage can occur. 9. specimen rotating holder keyword “specimen rotating holder ” A specimen holder which can rotate the specimen with respect to the direction of the incident electron beam. The range of rotation angles is ±180° and the range of tilt angle is about ±25°. 10. single-tilt heating holder keyword “single-tilt heating holder ” A specimen holder used to heat the specimen. The maximum temperature that can be reached is ~800 ℃. Tilt of the specimen is for only one axis (X axis) and the achievable tilt angle is ~±20°. Some holder can reach ~1000 ℃. Although the holder cannot adjust specimen orientation perfectly, it can be easily operated and is inexpensive than a double-tilt heating holder. 11. double-tilt heating holder keyword “double-tilt heating holder ” A specimen holder which can heat the specimen and also tilt about the X and Y axes (double axes). The maximum temperature attained is ~800 ℃. Some holder achieves ~1000 ℃. The range of tilt angle is ~±20°. 12. specimen drift keyword “ specimen drift ” "Specimen drift" means the amount of specimen movements that arise from thermal or mechanical instability of the goiometer, specimen holder, etc. Specimen drift is an important factor that degrades high-resolution image and micro (nano) area analysis. Normally, the drift is suppressed to ~1 nm/min. 13-1. double-tilt holder keyword “ double-tilt holder ” A specimen holder in which the specimen can be tilted about the X and Y axes (double axes). Specimen tilt angle depends on the objective-lens polepiece, ranging between ±20° and ±60°. 13-2. double-tilt heating holder A specimen holder which can heat the specimen and also tilt about the X and Y axes (double axes). The maximum temperature attained is ~800 ℃. Some holder achieves ~1000 ℃. The range of tilt angle is ~±20°. 13-3. double-tilt cooling holder A specimen holder in which the specimen can be cooled and also tilted about the X and Y axes (double axes). The temperature variable range and the minimum temperature holding time of the liquid-nitrogen cooling holder are -175 ℃ (~100 K) to +50 ℃ and 2 to 3 hours, respectively. The temperature variable range and the minimum temperature holding time of the liquid-helium cooling holder are 20 K to 100 K and about 1 hour, respectively. 13-4. double-tilt beryllium holder A specimen holder made of beryllium, which can tilt a specimen about the X and Y axes and enables high-sensitivity EDS analysis. Since beryllium absorbs hard X-rays that form background for characteristic X-rays, the detection efficiency is improved. It should be noted that the holder cannot be handled with bare hands due to strong poisonous property of beryllium. 14. single-tilt cooling holder keyword “ single-tilt cooling holder ” A specimen holder used to cool the specimen with liquid nitrogen or liquid helium. Tilt of the specimen is for only one axis (X axis). Some liquid-helium cooling holder can be cooled down to 5 K. Although the holder cannot adjust specimen orientation perfectly, it can be easily operated and is inexpensive than a double-tilt cooling holder. 15. double-tilt cooling holder keyword “ double-tilt cooling holder ” A specimen holder in which the specimen can be cooled and also tilted about the X and Y axes (double axes). The temperature variable range and the minimum temperature holding time of the liquid-nitrogen cooling holder are -175 ℃ (~100 K) to +50 ℃ and 2 to 3 hours, respectively. The temperature variable range and the minimum temperature holding time of the liquid-helium cooling holder are 20 K to 100 K and about 1 hour, respectively. 16. top-entry stage keyword “ top-entry stage ” A specimen stage into which the specimen is inserted from above the polepiece of the objective lens. The "top-entry stage" has a construction where the specimen holder is rotationally symmetric with respect to the optical axis because it is inserted in the objective lens from the top. Since this stage is stable to vibrations and heating, it is advantageous for high-resolution image observation in an ultra-high voltage electron microscope, etc. However, due to the construction of the top-entry stage, large tilt angles of a specimen cannot be achieved, and analytical functions (tools) are difficult to be added. Due to these disadvantages, the side-entry stage is used for an analytical electron microscope. Related term side-entry stage 17. drift correction (cancellation) system keyword “ drift correction (cancellation) system ” A system to detect and correct image shift that arises when the specimen is moved or when the specimen temperature is changed. 18. stray magnetic field keyword “ stray magnetic field ” "Stray magnetic field(s)" are adverse magnetic fields that exist around the instrument. The stray magnetic fields are classified into static magnetic fields and alternating magnetic fields. The former includes non-periodic magnetic fields generated by cars and trains, and geomagnetism. The latter includes periodic magnetic fields generated by power supplies, fluorescent lamps and external devices. 19. double-tilt beryllium holder keyword “ double-tilt beryllium holder” A specimen holder made of beryllium, which can tilt a specimen about the X and Y axes and enables high-sensitivity EDS analysis. Since beryllium absorbs hard X-rays that form background for characteristic X-rays, the detection efficiency is improved. It should be noted that the holder cannot be handled with bare hands due to strong poisonous property of beryllium. 20. azimuth (azimuthal angle) keyword “ azimuth (azimuthal angle) ” In the case of a TEM, the "azimuthal angle" is a rotation angle around the optical axis. That is, an azimuth is defined as an angle between a plane that includes the optical axis and the reference plane also including the optical axis. 21. missing cone keyword “ missing cone ” In three-dimensional tomography, "missing cone" means a region where the projection information on the specimen cannot be obtained due to the limitation on the tilt angle of the specimen holder. This gives rise to artifacts. To reconstruct a high-accuracy three-dimensional image, decreasing the angle for the missing cone is more important than increasing the number of tilt-series images. The tilt angle of the ordinary goniometer is limited to ±60°. Related term tomography 22. eucentric goniometer keyword “ eucentric goniometer ” A specimen stage, which is designed in such a way that the tilt axis of the stage is placed on the specimen plane. Thus, the center of the image of the specimen does not shift during specimen tilt.