scholarly journals Unstable resonators with Gosper-island boundary conditions: Virtual-source computation of fractal eigenmodes

Author(s):  
J. M. Christian ◽  
J. G. Huang
Optik ◽  
2012 ◽  
Vol 123 (20) ◽  
pp. 1810-1814 ◽  
Author(s):  
Gen Li ◽  
Xiahui Tang ◽  
Yingxiong Qin ◽  
Chao Wu

Author(s):  
John W. Coleman

In the design engineering of high performance electromagnetic lenses, the direct conversion of electron optical design data into drawings for reliable hardware is oftentimes difficult, especially in terms of how to mount parts to each other, how to tolerance dimensions, and how to specify finishes. An answer to this is in the use of magnetostatic analytics, corresponding to boundary conditions for the optical design. With such models, the magnetostatic force on a test pole along the axis may be examined, and in this way one may obtain priority listings for holding dimensions, relieving stresses, etc..The development of magnetostatic models most easily proceeds from the derivation of scalar potentials of separate geometric elements. These potentials can then be conbined at will because of the superposition characteristic of conservative force fields.


Author(s):  
T. Miyokawa ◽  
S. Norioka ◽  
S. Goto

Field emission SEMs (FE-SEMs) are becoming popular due to their high resolution needs. In the field of semiconductor product, it is demanded to use the low accelerating voltage FE-SEM to avoid the electron irradiation damage and the electron charging up on samples. However the accelerating voltage of usual SEM with FE-gun is limited until 1 kV, which is not enough small for the present demands, because the virtual source goes far from the tip in lower accelerating voltages. This virtual source position depends on the shape of the electrostatic lens. So, we investigated several types of electrostatic lenses to be applicable to the lower accelerating voltage. In the result, it is found a field emission gun with a conical anode is effectively applied for a wide range of low accelerating voltages.A field emission gun usually consists of a field emission tip (cold cathode) and the Butler type electrostatic lens.


1981 ◽  
Vol 64 (11) ◽  
pp. 18-26 ◽  
Author(s):  
Tetsuya Nomura ◽  
Nobuhiro Miki ◽  
Nobuo Nagai

2018 ◽  
Vol 103 (9) ◽  
pp. 1019-1038 ◽  
Author(s):  
Lin Wang ◽  
Bradley P. Owens ◽  
Junchao (Jason) Li ◽  
Lihua Shi

2009 ◽  
Author(s):  
Sabrina Volpone ◽  
Cristina Rubino ◽  
Ari A. Malka ◽  
Christiane Spitzmueller ◽  
Lindsay Brown

2008 ◽  
Author(s):  
Silke Atmaca ◽  
Antje Hollander ◽  
Wolfgang Prinz

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