scholarly journals Characteristics of Photon Beam and Preservation of Coherence in Fourth-Generation Light Sources

2021 ◽  
Vol 11 (24) ◽  
pp. 11896
Author(s):  
Bonghoon Oh ◽  
Jinjoo Ko ◽  
Jaeyu Lee ◽  
Gyeongsu Jang ◽  
Seunghwan Shin

Fourth-generation storage rings (4GSRs) that exploit the multi-bend achromat lattice concept may be able to surpass the brightness and coherence that are attained using the present third-generation storage rings. This paper presents the characteristics of photon beams and an analysis of their coherence properties in Korea-4GSR to represent 4GSRs.

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Seunghwan Shin

AbstractThere had been remarkable progress in developing third-generation electron storage rings as the main sources of very bright photon beams. Fourth-generation storage rings based on the multi-bend achromat lattice concept may be able to surpass the brightness and coherence that are attained using present third-generation storage rings. In this paper, we survey ongoing work around the world to develop concepts and designs for fourth-generation electron storage rings.


1998 ◽  
Vol 5 (3) ◽  
pp. 179-183 ◽  
Author(s):  
Motohiro Kihara

Many third-generation light sources have been commissioned over the past ten years, and the soundness of the principal design concepts has been well recognized through experiences at these facilities. Also, technological developments concerning third-generation light sources have been remarkable. With the emittance and current of the beams far exceeding the previous levels, stability requirements of the beams have become much more stringent. In this report the present status of light sources, operational and projected, is summarized, and developments and future prospects of synchrotron radiation storage rings in view of accelerator physics and technology are reviewed.


2014 ◽  
Vol 21 (5) ◽  
pp. 912-936 ◽  
Author(s):  
Michael Borland ◽  
Glenn Decker ◽  
Louis Emery ◽  
Vadim Sajaev ◽  
Yipeng Sun ◽  
...  

Third-generation low-emittance storage-ring light sources based on double- and triple-bend cells and undulator magnets have been in operation around the world for more than two decades. On the horizon is a new generation based on the multi-bend achromat (MBA) lattice concept promising two to three orders of magnitude higher brightness than is available in today's sources. In this paper, the challenges inherent in designing MBA lattices, as well as potential solutions, are described. Topics covered include lattice concepts, scaling of storage-ring performance, brightness optimization, nonlinear dynamics, beam lifetime and injection schemes.


Author(s):  
H. Sakai ◽  
I. Ito ◽  
H. Kudo ◽  
N. Nakamura ◽  
T. Shibuya ◽  
...  

2018 ◽  
Vol 18 (03) ◽  
pp. 280-284 ◽  
Author(s):  
Mohamed Bencheikh ◽  
Abdelmajid Maghnouj ◽  
Jaouad Tajmouati

AbstractAimThe purpose of this study is to introduce a new approach to assess the dosimetry quality of photon beam with energy and irradiation field size. This approach is based on percentage depth dose (PDD) fragmentation for investigating the dosimetry quality.Materials and methodsFor the investigation of the dosimetry quality of 6 and 18 MV photon beams, we have proceeded to fragment the PDD at different field sizes. This approach checks the overall PDD and is not restricted to the exponential decay regions, as per the International Atomic Energy Agency Technical Reports Series No 398 and the American Association of Physicist in Medicine Task Group 51 recommendations.Results and discussionThe 6 MV photon beam deposited more energy in the target volume than the 18 MV photon beam. The dose delivered by the 6 MV beam is greater by a factor of 1·5 than that delivered by the 18 MV beam in the build-up region and the dose delivered by the 6 MV beam is greater by a factor of 2·6 than that delivered by the 18 MV beam in the electronic equilibrium and the exponential decay regions.ConclusionThe dose measured at different points of the beam is higher for 6 MV than for 18 MV photon beam. Therefore, the 6 MV beam is more dosimetrically efficient than the 18 MV beam. Using the proposed approach, we can assess the dosimetry quality by taking into account overall PDD not only in the exponential decay region but also in the field.


2020 ◽  
Vol 26 ◽  
pp. 11-41
Author(s):  
Maciej Ziemierski

17th century testaments of the Królik family from Krakow The article is dedicated to the Królik family from Krakow, who lived in the town from the late 16th century until the first years of the 18th century. The family members initially worked as tailors, later reinforcing the group of Krakow merchants in the third generation (Maciej Królik). Wojciech Królik – from the fourth generation – was a miner in Olkusz. The text omits the most distinguished member of the family, Wojciech’s oldest brother, the Krakow councillor Mikołaj Królik, whose figure has been covered in a separate work. The work shows the complicated religious relations in the family of non-Catholics, initially highly engaged in the life of the Krakow Congregation, but whose members gradually converted from Evangelism to Catholicism. As a result, Wojciech Królik and his siblings became Catholics. This work is complemented by four testaments of family members, with the first, Jakub Królik’s, being written in 1626 and the last one, Wojciech Królik’s, written in 1691.


2012 ◽  
Vol 433-440 ◽  
pp. 2498-2503
Author(s):  
Quan Bo Yuan ◽  
Feng Juan Qu ◽  
Hui Zhao ◽  
Li Yuan Liu

At present,Chinese third-generation communications technology (3G) has been applied, and global internet of things technology development has been put on the agenda. The fourth-generation communication technology will be discussed based on the wireless communication field, mainly introducing the development situation of fourth-generation communication system. In the paper, the key technology will be discussed in detail, and is involved in domestic network development. Finally, the fourth-generation communication technology in the network is prospected.


2019 ◽  
Vol 26 (2) ◽  
pp. 386-392
Author(s):  
Michele Di Fraia ◽  
Antonio De Sio ◽  
Matias Antonelli ◽  
Renzo Nesti ◽  
Dario Panella ◽  
...  

The improved performance of third-generation light sources and the advent of next-generation synchrotron radiation facilities require the use of extremely precise monitoring of the main photon-beam parameters, such as position, absolute and relative intensity, and temporal structure. These parameters, and associated real-time feedbacks, are fundamental at the beamline control level and at the machine control level, to improve the stability of the photon beams and to provide bunch-to-bunch quantitative information. Fast response time, high radiation hardness and visible–blind response are main features of photon-beam monitors for VUV and X-ray synchrotron radiation beamlines; hence diamond-based detectors are outstanding candidates. Here, results are presented of an extensive measurement campaign aiming at optimizing the capabilities of diamond detectors to discern time structures below the 100 ps timescale. A custom-built device has been fabricated and tested at the Italian Synchrotron Radiation Laboratory Elettra in Trieste. The results obtained show that diamond is an excellent material for ultra-fast photon pulses with picosecond time resolution; finally the possibilities for application at free-electron laser sources are discussed.


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