Chapter/Index: Introduction | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Appendix
| Since the first 200 and 300 kV FEGTEMs (field emission gun TEMs) had been sold by JEOL and Philips, the sales of FEGTEMs were rising steadily. Cheap EM sales can happen when some companies fail and then close their business and fabs. For instance, some organizations and people bought some used EM systems (but they were still new or in good conditions) when: -- Solyndra solar company, Fremont, California: A company that initially served as a showcase for the Obama administration’s effort to create jobs in clean technology shut down and laid off all the employees (1,100 people) and taxpayers obligated for $535 million in federal loans. In 2009 and 2010, President Obama and Energy Secretary Steven Chu each had actually made congratulatory visits to the company’s Silicon Valley headquarters. The prices for purchasing those used tools are normally great because the companies want to get rid of their tools quickly. Furthermore, it should be realized that many experimental settings for EM demonstrations (e.g. provided by EM manufacturers) are often impractical for routine characterizations of actual materials. Before purchasing a tool, one needs to investigate and understand the general and special specification of the tools, and to make sure the service of this company in the area is good. In general, however, the users do not need to understand or even be aware of the pumping arrangement since the pumping sequence is automatic and safety devices ensure that a specific pump and the microscope cannot operate until an appropriate vacuum is obtained. However, there are various pumps for TEMs and SEMs, and one often has a choice and needs to make a decision when purchasing an instrument. Note that a clean UHV (ultra-high vacuum) system is very expensive. Furthermore, if you buy a new TEM or a pump for an old TEM, you will need to specify that the operation of pumps (e.g. mechanical pumps) will not transmit vibrations to the microscope column if high resolution is needed. Ion pumps are often directly added to the specimen stage (especially for analytical EMs) or gun chambers of EMs to enhance the vacuum in these important regions. The last things we need to consider before purchasing a EM system are who will use the tool properly and maintain its functionality. Electron microscopes are expensive, large instruments and require careful installation and regular maintenance. The performances of specific instruments vary from model to model and manufacturer to manufacturer even though they are trying to match each other due to market competition. Because of the complexity of the instruments and the phenomena related to materials and interaction between energetic electrons and materials, it is a process of years rather than weeks or months to become a proficient electron microscpist. Some notes about microscope service strategies:
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