Abstract-Producing terahertz coherent synchrotron radiation at the Hefei Light Source

Xu De-Rong (许德荣), Xu Hong-Liang (徐宏亮) and Shao Yan (邵琰)

http://iopscience.iop.org/1674-1137/39/7/077003/pdf/1674-1137_39_7_077003.pdf
xuderong@mail.ustc.edu.cn hlxu@ustc.edu.cn shaoyan1@mail.ustc.edu.cn

National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China
 

Xu De-Rong et al 2015 Chinese Phys. C 39 077003. doi:10.1088/1674-1137/39/7/077003
Received 28 September 2014.
©2015 Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Sciences and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd

This paper theoretically proves that an electron storage ring can generate coherent radiation in the THz region using a quick kicker magnet and an AC sextupole magnet. When the vertical chromaticity is modulated by the AC sextupole magnet, the vertical beam collective motion excited by the kicker produces a wavy spatial structure after a number of longitudinal oscillation periods. The radiation spectral distribution was calculated from the wavy bunch parameters at the Hefei Light Source (HLS). When the electron energy is reduced to 400 MeV, extremely strong coherent synchrotron radiation (CSR) at 0.115 THz should be produced.

Abstract-An ultra-fast data acquisition system for coherent synchrotron radiation with terahertz detectors

M Casellea, M Balzera, S Chilingaryana, M Hofherrb, V Judinc, A Kopmanna, N J Smaled, P Thomab, S Wuenschb, A -S Müllerc, M Siegelb and M Webera

http://iopscience.iop.org/1748-0221/9/01/C01024

michele.caselle@kit.edu

a IPE Department — Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
b IMS Department — Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
c LAS Department — Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
d ANKA Facility Department — Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany 

Part of Topical Workshop on Electronics for Particle Physics 2013 (TWEPP-13)

The recording of coherent synchrotron radiation requires data acquisition systems with a temporal resolution of tens of picosecond. This paper describes a new real-time and high-accuracy data acquisition system suitable for recording individual ultra-short pulses generated by a fast terahertz (THz) detector (e.g. YBCO, NbN, Zero Biased Schottky Diode). The system consists of a fast sampling board combined with a high data throughput readout. The first board is designed for sampling the fast pulse signals with a full width half maximum (FWHM) between a few tens to one hundred picoseconds with a minimum sampling time of 3 ps. The high data throughput board consists of a PCIe-Bus Master DMA architecture used for fast data transfer up to 3 GByte/s. The full readout chain with fast THz detectors and the acquisition system has been successfully tested at the synchrotron ANKA. An overview of the electronics system and preliminary results with multi-bunch filling pattern will be presented.

Abstract-Terahertz Light Source Based on Synchrotron Radiation

• Masahiro Katoh

http://link.springer.com/chapter/10.1007%2F978-3-642-40594-5_10

Synchrotron radiation is an electromagnetic wave emitted by relativistic electrons traveling in a strong magnetic field. It provides intense, highly collimated, highly polarized, pulsed, and extremely broadband light source, which is widely used in various research fields especially in the X-ray range. It can also be used in the infrared and terahertz range because it also has a strong spectral component in these regions. In this paper, I Introduce a new way to enhance the infrared and terahertz component of the radiation by far to several orders in the magnitude, using coherent synchrotron radiation. New light source technologies based on the coherent synchrotron radiation are being developed at UVSOR at Institute of Molecular Science, Japan, which will be powerful tools for terahertz applications. Using this light source, we can also utilize the coherence of the radiation for spectroscopy, which was difficult in the studies using normal synchrotron radiation.

Abstract-Observation of superradiant synchrotron radiation in the terahertz region

B. E. Billinghurst, J. C. Bergstrom, L. Dallin, M. de Jong, T. E. May, J. M. Vogt, and W. A. Wurtz
http://prst-ab.aps.org/accepted/27079Y7eF5c1d62839d606c1bd5fcc28232c2de54

We report the first high-resolution measurement of superradiance, using coherent synchrotron radiation in the terahertz region from the Canadian Light Source synchrotron and a Michelson interferometer with a nominal frequency resolution of 0.00096~cm$^{-1}$. Superradiance arises when a high degree of phase coherence exists between the radiation fields of the individual electron bunches, and manifests itself as a series of narrow spectral peaks at harmonics of the bunch frequency. We observe an enhancement factor of 16 at the spectral peaks, limited by the interferometer resolution. The spectral distribution and relative amplitudes of the superradiant peaks are modified by altering the pattern of bunches along the bunch train.

Abstract-Coherent synchrotron radiation for broadband terahertz spectroscopy

J. Barros¹, C. Evain², L. Manceron¹, J.-B. Brubach¹, M.-A. Tordeux¹, P. Brunelle¹, L. Nadolski¹, A. Loulergue¹, M.-E. Couprie¹, S. Bielawski², C. Szwaj², and P. Roy¹

¹Synchrotron SOLEIL, Saint Aubin, BP 48, 91192 Gif-sur-Yvette, Cedex, France
²Laboratoire de Physique des Lasers, Atomes et Molécules, Université des Sciences et Technologies de Lille, F-59655 Villeneuve d’Ascq Cedex, France                        

We present the first high resolution (10⁻³ cm⁻¹) interferometric measurements in the 200–750 GHz range using coherent synchrotron radiation, achieved with a low momentum compaction factor. The effect of microbunching on spectra is shown, depending on the bunch current. A high signal-to-noise ratio is reached thanks to an artifact correction system based on a double detection scheme. Combined to the broad emitted spectral range and high flux (up to 10⁵ times the incoherent radiation), this study demonstrates that coherent synchrotron radiation can now be used for stability-demanding applications, such as gas-phase studies of unstable molecules.

© 2013 American Institute of Physics