Compact high brightness radiation sources

1996 ◽  
Author(s):  
K. Imasaki ◽  
M. Fujita ◽  
J. Chen ◽  
M. Asakawa ◽  
S. Nakai ◽  
...  
Keyword(s):  
High Brightness ◽  
Radiation Sources

Maximum at ALS: A Powerful Tool to Investigate Open Problems in Micro and Optoelectronics

1998 ◽  
Vol 524 ◽  
Author(s):  
G. F. Lorusso ◽  
H. Solak ◽  
S. Singh ◽  
P. J. Batson ◽  
J. H. Underwood ◽  
...  
Keyword(s):  
Thin Films ◽  
Synchrotron Radiation ◽  
Spectral Resolution ◽  
National Laboratory ◽  
Third Generation ◽  
Energy Analyzer ◽  
Open Problems ◽  
High Brightness ◽  
The Third ◽  
Radiation Sources

ABSTRACTWe present recent results obtained by MAXIMUM at the Advanced Light Source (ALS), at the Lawrence Berkeley National Laboratory. MAXIMUM is a scanning photoemission microscope, based on a multilayer coated Schwarzschild objective. An electron energy analyzer collects the emitted photoelectrons to form an image as the sample itself is scanned. The microscope has been purposely designed to take advantage of the high brightness of the third generation synchrotron radiation sources, and it installation at ALS has been recently completed. The spatial resolution of 100 nm and the spectral resolution of 200 meV make our instrument an extremely interesting tool to investigate current problems in opto- and microelectronics. In order to illustrate the potential of MAXIMUM in these fields, we report new results obtained by studying the electromigration in Al-Cu lines and the Al segregation in AIGaN thin films.

HIGH BRIGHTNESS BEAMS — APPLICATIONS TO FREE-ELECTRON LASERS

2007 ◽  
Vol 22 (22) ◽  
pp. 3912-3924
Author(s):  
SVEN REICHE
Keyword(s):  
Free Electron ◽  
Beam Quality ◽  
Beam Parameter ◽  
Free Electron Lasers ◽  
High Quality ◽  
High Brightness ◽  
Radiation Sources ◽  
Beam Parameters ◽  
The Impact

Free-Electron Lasers as high-brilliance radiation sources, rely on a high quality of the electron beam driving the FEL process. The amount of energy, transferred from the electrons to the radiation field, and thus the efficiency of the FEL depends on the provided beam parameters. The presentation discusses the impact of various beam parameter and how current designs of FEL injector try to accomplish the demands on the beam quality for reaching saturation.

scholarly journals Finite-Difference Time-Domain (FDTD) Simulation of Novel Terahertz Structures

2014 ◽  
Vol 13 (2) ◽  
pp. 4164-4182
Author(s):  
Yasser Hussein ◽  
James E. Spencer ◽  
Samir El-Ghazaly
Keyword(s):  
Semiconductor Lasers ◽  
Fdtd Simulation ◽  
Angular Distributions ◽  
Free Electrons ◽  
High Brightness ◽  
Radiated Power ◽  
Radiation Sources ◽  
Basic Parameters ◽  
Magnetic Resonance Imaging Mri ◽  
Difference Time

Previous work on compact, variable, efficient, high brightness radiation sources is extended by calculating the radiated power and angular distributions for different configurations and drive sources. Figures of merit are defined in terms of efficiencies or effective impedances such as the radiation coupling impedance Zr .Characteristics of representative cases are discussed in terms of a few basic parameters. Conditions for interference are discussed and demonstrated. Finally, we discuss some further possibilities together with various impediments to realizing such devices. The differences between bound and free electrons are studied from the standpoint of the frequencies that are practicably achievable. With the ansatz that the transport physics with Maxwell’s Equations are valid but modified by the material properties, a number of analogs exist between these two basic sources of radiation. In many cases, the differences are between macro and micro implementations e.g. between klystrons and klystrinos (micro or nano)  or solid state and semiconductor lasers or rare-earth doped transistors. Cases with no apparent analogs are ones due to unique quantum effects e.g. radiation at 3kTc in superconductors. This is well above magnetic resonance imaging MRI around 0.4 eV but well below room temperature at 25 meV. Bound and free possibilities for planar, micro undulators over this range are studied using FDTD techniques. To our knowledge, there have been no implementations of either possibility.

Compact high-brightness radiation sources

1995 ◽  
Vol 358 (1-3) ◽  
pp. 14-17 ◽  
Author(s):  
J. Chen ◽  
K. Imasaki ◽  
M. Fujita ◽  
M. Asakawa ◽  
T. Asakuma ◽  
...  
Keyword(s):  
High Brightness ◽  
Radiation Sources

A Stable Field Emission Electron Source

1977 ◽  
Vol 35 ◽  
pp. 58-59
Author(s):  
W.R. Bottoms ◽  
G.B. Haydon
Keyword(s):  
Field Emission ◽  
Signal To Noise Ratio ◽  
High Brightness ◽  
Electron Sources ◽  
Brightness Field ◽  
Current Densities ◽  
Properties Of Materials ◽  
Stable Field ◽  
Stable Current ◽  
Careful Design

There is great interest in improving the brightness of electron sources and therefore the ability of electron optical instrumentation to probe the properties of materials. Extensive work by Dr. Crew and others has provided extremely high brightness sources for certain kinds of analytical problems but which pose serious difficulties in other problems. These sources cannot survive in conventional system vacuums. If one wishes to gather information from the other signal channels activated by electron beam bombardment it is necessary to provide sufficient current to allow an acceptable signal-to-noise ratio. It is possible through careful design to provide a high brightness field emission source which has the capability of providing high currents as well as high current densities to a specimen. In this paper we describe an electrode to provide long-lived stable current in field emission sources.The source geometry was based upon the results of extensive computer modeling. The design attempted to maximize the total current available at a specimen.

Optical Properties of HVEM Accelerators

1975 ◽  
Vol 33 ◽  
pp. 180-181
Author(s):  
A. Strojnik ◽  
J.W. Scholl ◽  
V. Bevc
Keyword(s):  
Optical Properties ◽  
Electron Accelerator ◽  
Systematic Investigation ◽  
Electron Source ◽  
High Brightness ◽  
The Past ◽  
Wide Range ◽  
Optical Behavior

The electron accelerator, as inserted between the electron source (injector) and the imaging column of the HVEM, is usually a strong lens and should be optimized in order to ensure high brightness over a wide range of accelerating voltages and illuminating conditions. This is especially true in the case of the STEM where the brightness directly determines the highest resolution attainable. In the past, the optical behavior of accelerators was usually determined for a particular configuration. During the development of the accelerator for the Arizona 1 MEV STEM, systematic investigation was made of the major optical properties for a variety of electrode configurations, number of stages N, accelerating voltages, 1 and 10 MEV, and a range of injection voltages ϕ0 = 1, 3, 10, 30, 100, 300 kV).

Characteristics and Application of Temperature-Field Emitters

1975 ◽  
Vol 33 ◽  
pp. 144-145
Author(s):  
N. Tamura ◽  
T. Goto ◽  
Y. Harada
Keyword(s):  
Temperature Field ◽  
Electron Microscope ◽  
Field Emission ◽  
Resolving Power ◽  
High Brightness ◽  
Field Emitters ◽  
Emission Electron ◽  
Sufficient Stability ◽  
Scanning Electron ◽  
Illuminating System

On account of its high brightness, the field emission electron source has the advantage that it provides the conventional electron microscope with highly coherent illuminating system and that it directly improves the, resolving power of the scanning electron microscope. The present authors have reported some results obtained with a 100 kV field emission electron microscope.It has been proven, furthermore, that the tungsten emitter as a temperature field emission source can be utilized with a sufficient stability under a modest vacuum of 10-8 ~ 10-9 Torr. The present paper is concerned with an extension of our study on the characteristics of the temperature field emitters.

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