Positron versus electron‐beam quality in low emittance storage rings (invited)

1992 ◽  
Vol 63 (1) ◽  
pp. 327-330
Author(s):  
P. C. Marin
Keyword(s):  
Electron Beam ◽  
Beam Quality ◽  
Storage Rings ◽  
Low Emittance

scholarly journals Coherence properties of the high-energy fourth-generation X-ray synchrotron sources

2019 ◽  
Vol 26 (6) ◽  
pp. 1851-1862 ◽  
Author(s):  
R. Khubbutdinov ◽  
A. P. Menushenkov ◽  
I. A. Vartanyants
Keyword(s):  
Electron Beam ◽  
Storage Ring ◽  
High Energy ◽  
Storage Rings ◽  
Relative Energy ◽  
Diffraction Limit ◽  
Energy Spread ◽  
Fourth Generation ◽  
X Ray ◽  
Low Emittance

An analysis of the coherence properties of the fourth-generation high-energy storage rings with emittance values of 10 pm rad is performed. It is presently expected that a storage ring with these low emittance values will reach diffraction limit at hard X-rays. Simulations of coherence properties were performed with the XRT software and an analytical approach for different photon energies from 500 eV to 50 keV. It was demonstrated that a minimum photon emittance (diffraction limit) reached at such storage rings is λ/2π. Using mode decomposition it is shown that, for the parameters of the storage ring considered in this work, the diffraction limit will be reached for soft X-ray energies of 500 eV. About ten modes will contribute to the radiation field at 12 keV photon energy and even more modes give a contribution at higher photon energies. Energy spread effects of the electron beam in a low-emittance storage ring were analysed in detail. Simulations were performed at different relative energy spread values from zero to 2 × 10−3. A decrease of the degree of coherence with an increase of the relative energy spread value was observed. This analysis shows that, to reach the diffraction limit for high photon energies, electron beam emittance should go down to 1 pm rad and below.

Electromagnetic-wave-pumped free-electron laser in a plasma channel

1997 ◽  
Vol 58 (4) ◽  
pp. 613-621 ◽  
Author(s):  
JETENDRA PARASHAR ◽  
H. D. PANDEY ◽  
A. K. SHARMA ◽  
V. K. TRIPATHI
Keyword(s):  
Electron Beam ◽  
Electromagnetic Wave ◽  
Laser Radiation ◽  
Laser Pulse ◽  
Free Electron Laser ◽  
Relativistic Electron Beam ◽  
Plasma Channel ◽  
Beam Quality ◽  
Coherent Radiation ◽  
Millimetre Wave

An intense short laser pulse or a millimetre wave propagating through a plasma channel may act as a wiggler for the generation of shorter wavelengths. When a relativistic electron beam is launched into the channel from the opposite direction, the laser radiation is Compton/Raman backscattered to produce coherent radiation at shorter wavelengths. The scheme, however, requires a superior beam quality with energy spread less than 1% in the Raman regime.

scholarly journals High gradient quadrupoles for low emittance storage rings

2016 ◽  
Vol 19 (5) ◽  
Author(s):  
G. Le Bec ◽  
J. Chavanne ◽  
C. Benabderrahmane ◽  
L. Farvacque ◽  
L. Goirand ◽  
...  
Keyword(s):  
Storage Rings ◽  
High Gradient ◽  
Low Emittance

A 200keV Gun with NEA-GaAs Photocathode to Produce Low Emittance Electron Beam

2004 ◽  
pp. II-39-II-40
Author(s):  
M. Yamamoto ◽  
K. Wada ◽  
N. Yamamoto ◽  
T. Nakanishi ◽  
S. Okumi ◽  
...  
Keyword(s):  
Electron Beam ◽  
Low Emittance

scholarly journals Manipulation of Laser Distribution to Mitigate the Space-Charge Effect for Improving the Performance of a THz Coherent Undulator Radiation Source

Particles ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 238-252 ◽  
Author(s):  
Siriwan Krainara ◽  
Shuya Chatani ◽  
Heishun Zen ◽  
Toshiteru Kii ◽  
Hideaki Ohgaki
Keyword(s):  
Electron Beam ◽  
Space Charge ◽  
Electron Bunch ◽  
Beam Quality ◽  
Space Charge Effect ◽  
Bunch Length ◽  
Charge Effect ◽  
Simulation Code ◽  
Undulator Radiation ◽  
Radiated Power

A THz coherent undulator radiation (THz-CUR) source has been developed at the Institute of Advanced Energy, Kyoto University. A photocathode Radio-Frequency (RF) gun and a bunch compressor chicane are used for generating short-bunch electron beams. When the electron beam energy is low, the space-charge effect strongly degrades the beam quality, such as the bunch length and the energy spread at the high bunch charge condition at around 160 pC, and results in the reduction of the highest frequency and the maximum radiated power of the THz-CUR. To mitigate the space charge effect, we have investigated the dependence of the electron beam quality on the laser distribution in transverse and longitudinal directions by using a numerical simulation code, General Particle Tracer GPT. The manipulation of the laser distribution has potential for improving the performance of the THz-CUR source. The electron bunch was effectively compressed with the chicane magnet when the laser transverse distribution was the truncated Gaussian profile, illuminating a cathode. Moreover, the compressed electron bunch was shortened by enlarging the laser pulse width. Consequently, an enhancement of the radiated power of the THz-CUR has been indicated.

scholarly journals Synchrotron Radiation Sources – Present Capabilities and Future Directions

1998 ◽  
Vol 5 (3) ◽  
pp. 168-175 ◽  
Author(s):  
Herman Winick
Keyword(s):  
Electron Beam ◽  
High Energy ◽  
Storage Rings ◽  
Light Sources ◽  
Beam Emittance ◽  
High Brightness ◽  
Performance Levels ◽  
Electron Sources ◽  
Short Period ◽  
Pass Through

Many of the more than 40 operational light sources around the world have achieved performance levels that exceed initial design goals. These accomplishments are reviewed, along with concepts and proposals for sources with performance levels exceeding those of present sources. These include storage rings with lower electron-beam emittance than present third-generation rings and free-electron lasers (FELs). It now appears that the highest performance sources will be based on linacs rather than storage rings. This is because emittance originates differently and scales differently with electron energy for rings and linacs, so that the lowest electron-beam emittance can be achieved in high-energy linacs equipped with high-brightness electron sources. Such electron beams can be used to provide X-ray beams with very high brightness and coherence in sub-picosecond pulses in a single pass through a small-gap short-period undulator by spontaneous emission, and with even higher beam brightness and coherence by stimulated coherent emission in an FEL. Designs for such FEL sources, and associated research and development, are underway at several laboratories.

New challenges in beamline instrumentation for the ESRF Upgrade Programme Phase II

2014 ◽  
Vol 21 (5) ◽  
pp. 986-995 ◽  
Author(s):  
Jean Susini ◽  
Raymond Barrett ◽  
Joel Chavanne ◽  
Pablo Fajardo ◽  
Andy Götz ◽  
...  
Keyword(s):  
Phase Ii ◽  
New Technologies ◽  
Storage Rings ◽  
Successful Implementation ◽  
New Science ◽  
Source Characteristics ◽  
Scientific Instrumentation ◽  
Horizontal Beam ◽  
Scientific Potential ◽  
Low Emittance

Although beamline instrumentation is by nature driven by science, some recent examples serve as reminders that new technologies also enable new science. Indeed, exploiting the full scientific potential of forthcoming new storage rings with unprecedented source characteristics will, in many cases, require the development and implementation of novel instrumentation. In comparison with present synchrotron radiation facilities, the majority of beamlines should reap immediate performance benefits from the improved source emittance, principally through increased flux and/or horizontal beam size reduction at the sample. Instrumentation will have to develop along similar quantitative and qualitative trends. More speculative and more challenging is anticipating instrumentation that will be required by the new science made possible thanks to the unique coherence properties of diffraction-limited storage rings (DLSRs). ESRF has recently carried out a detailed feasibility study for a new ultra-low-emittance 6 GeV hybrid multibend storage ring, identified as ESRF Upgrade Programme Phase II. Although its performance is not expected to be equivalent to a DLSR source, the successful implementation of the ESRF Phase II project has to address scientific instrumentation issues that are also common to DLSRs. This article aims at providing a comprehensive review of some of the challenges encountered by the ESRF, in the context of the preparation of Phase II of its upgrade programme.

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