Electro-optic Techniques in Electron Beam Diagnostics

Electro-optic Techniques in Electron Beam Diagnostics PDF Author:
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Category :
Languages : en
Pages :

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Electron accelerators such as laser wakefield accelerators, linear accelerators driving free electron lasers, or femto-sliced synchrotrons, are capable of producing femtosecond-long electron bunches. Single-shot characterization of the temporal charge profile is crucial for operation, optimization, and application of such accelerators. A variety of electro-optic sampling (EOS) techniques exists for the temporal analysis. In EOS, the field profile from the electron bunch (or the field profile from its coherent radiation) will be transferred onto a laser pulse co-propagating through an electro-optic crystal. This paper will address the most common EOS schemes and will list their advantages and limitations. Strong points that all techniques share are the ultra-short time resolution (tens of femtoseconds) and the single-shot capabilities. Besides introducing the theory behind EOS, data from various research groups is presented for each technique.

Electro-optic Techniques in Electron Beam Diagnostics

Electro-optic Techniques in Electron Beam Diagnostics PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Electron accelerators such as laser wakefield accelerators, linear accelerators driving free electron lasers, or femto-sliced synchrotrons, are capable of producing femtosecond-long electron bunches. Single-shot characterization of the temporal charge profile is crucial for operation, optimization, and application of such accelerators. A variety of electro-optic sampling (EOS) techniques exists for the temporal analysis. In EOS, the field profile from the electron bunch (or the field profile from its coherent radiation) will be transferred onto a laser pulse co-propagating through an electro-optic crystal. This paper will address the most common EOS schemes and will list their advantages and limitations. Strong points that all techniques share are the ultra-short time resolution (tens of femtoseconds) and the single-shot capabilities. Besides introducing the theory behind EOS, data from various research groups is presented for each technique.

Optical Sideband Generation

Optical Sideband Generation PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Electro-optic sampling (EOS) is widely used as a technique to measure THz-domain electric field pulses such asthe self-fields of femtosecond electron beams. We present an EOS-based approach for single-shot spectral measurement that excels in simplicity (compatible with fiber integration) and bandwidth coverage (overcomes the laser bandwidth limitation), allowing few-fs electron beams or single-cycle THz pulses to be characterized with conventional picosecond probes. It is shown that the EOS-induced optical sidebands on the narrow-bandwidth optical probe are spectrally-shifted replicas of the THz pulse. An experimental demonstration on a 0-3 THz source is presented.

Introduction to Electron Optics

Introduction to Electron Optics PDF Author: Vernon Ellis Cosslett
Publisher:
ISBN:
Category : Electron beams
Languages : en
Pages : 312

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Longitudinal Diagnostics for Short Electron Beam Bunches

Longitudinal Diagnostics for Short Electron Beam Bunches PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

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Book Description
Single-pass free electron lasers require high peak currents from ultra-short electron bunches to reach saturation and an accurate measurement of bunch length and longitudinal bunch profile is necessary to control the bunch compression process from low to high beam energy. The various state-of-the-art diagnostics methods from ps to fs time scales using coherent radiation detection, RF deflection, and other techniques are presented. The use of linear accelerators as drivers for free electron lasers (FEL) and the advent of single-pass (SASE) FELs has driven the development of a wide range of diagnostic techniques for measuring the length and longitudinal distribution of short and ultra-short electron bunches. For SASE FELs the radiation power and the length of the undulator needed to achieve saturation depend strongly on the charge density of the electron beam. In the case of X-ray FELs, this requires the accelerator to produce ultra-high brightness beams with micron size transverse normalized emittances and peak currents of several kA through several stages of magnetic bunch compression. Different longitudinal diagnostics are employed to measure the peak current and bunch profile along these stages. The measurement techniques can be distinguished into different classes. Coherent methods detect the light emitted from the beam by some coherent radiation process (spectroscopic measurement), or directly measure the Coulomb field traveling with the beam (electro-optic). Phase space manipulation techniques map the time coordinate onto a transverse dimension and then use conventional transverse beam diagnostics (transverse deflector, rf zero-phasing). Further methods measure the profile or duration of an incoherent light pulse emitted by the bunch at wavelengths much shorted than the bunch length (streak camera, fluctuation technique) or modulate the electron beam at an optical wavelength and then generate a narrow bandwidth radiation pulse with the longitudinal profile of the beam mapped onto (optical replicator). The operational needs for bunch length measurements to have fast acquisitions, to be used in feedback systems, to distinguish pulse to pulse changes and to be nondestructive or parasitically have resulted into developing many of the diagnostics into single-shot techniques and in the following the main discussion will emphasize them.

2D Optical Streaking for Ultra-Short Electron Beam Diagnostics

2D Optical Streaking for Ultra-Short Electron Beam Diagnostics PDF Author:
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Category :
Languages : en
Pages :

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Book Description
We propose a novel approach to measure short electron bunch profiles at micrometer level. Low energy electrons generated during beam-gas ionization are simultaneously modulated by the transverse electric field of a circularly-polarized laser, and then they are collected at a downstream screen where the angular modulation is converted to a circular shape. The longitudinal bunch profile is simply represented by the angular distribution of the electrons on the screen. We only need to know the laser wavelength for calibration and there is no phase synchronization problem. Meanwhile the required laser power is also relatively low in this setup. Some simulations examples and experimental consideration of this method are discussed. At Linac Coherent Light Source (LCLS), an S-band RF transverse deflector (TCAV) is used to measure the bunch length with a resolution 10 femtosecond (fs) rms. An X-band deflector (wavelength 2.6cm) is proposed recently to improve the resolution. However, at the low charge operation mode (20pC), the pulse length can be as short as fs. It is very challenging to measure femtosecond and sub-femtosecond level bunch length. One of the methods is switching from RF to [mu]m level wavelength laser to deflect the bunch. A powerful laser (≈10s GW) is required to deflect such a high energy beam (GeV) in a wiggler. Synchronization is another difficulty: the jitter between the bunch and the laser can be larger than the laser wavelength, which makes single-shot measurement impossible. To reduce the laser power, we propose to use ionized electrons from high energy electron beam and gas interaction for high energy electron bunch diagnostics. Similarly, the femtosecond X-ray streak camera uses X-ray ionization electrons to measure the X-ray pulse. The electrons generated by beam-gas ionization have low energy (eVs). Therefore, a lower laser power is possible to deflect such low energy electrons. Note that there is no field ionization in our case. To avoid field ionization, which occurs in plasma case, gases species with high field ionization threshold should be considered. For a linear polarized laser, the kick to the ionized electrons depends on the phase of the laser when the electrons are born and the unknown timing jitter between the electron beam and laser beam makes the data analysis very difficult. Here we propose to use a circular polarized laser to do a 2-dimensional (2D) streaking (both x and y) and measure the bunch length from the angular distribution on the screen, where the phase jitter causes only a rotation of the image on the screen without changing of the relative angular distribution. Also we only need to know the laser wavelength for calibration. A similar circular RF deflecting mode was used to measure long bunches. We developed a numerical particle-in-Cell (PIC) code to study the dynamics of ionization electrons with the high energy beam and the laser beam.

Metrology and Diagnostic Techniques for Nanoelectronics

Metrology and Diagnostic Techniques for Nanoelectronics PDF Author: Zhiyong Ma
Publisher: CRC Press
ISBN: 1351733958
Category : Science
Languages : en
Pages : 1454

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Book Description
Nanoelectronics is changing the way the world communicates, and is transforming our daily lives. Continuing Moore’s law and miniaturization of low-power semiconductor chips with ever-increasing functionality have been relentlessly driving R&D of new devices, materials, and process capabilities to meet performance, power, and cost requirements. This book covers up-to-date advances in research and industry practices in nanometrology, critical for continuing technology scaling and product innovation. It holistically approaches the subject matter and addresses emerging and important topics in semiconductor R&D and manufacturing. It is a complete guide for metrology and diagnostic techniques essential for process technology, electronics packaging, and product development and debugging—a unique approach compared to other books. The authors are from academia, government labs, and industry and have vast experience and expertise in the topics presented. The book is intended for all those involved in IC manufacturing and nanoelectronics and for those studying nanoelectronics process and assembly technologies or working in device testing, characterization, and diagnostic techniques.

Nuclear Science Abstracts

Nuclear Science Abstracts PDF Author:
Publisher:
ISBN:
Category : Nuclear energy
Languages : en
Pages : 1166

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Electron Beam Testing Technology

Electron Beam Testing Technology PDF Author: John T.L. Thong
Publisher: Springer Science & Business Media
ISBN: 1489915222
Category : Science
Languages : en
Pages : 467

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Book Description
Although exploratory and developmental activity in electron beam testing (EBT) 25 years, it was not had already been in existence in research laboratories for over until the beginning of the 1980s that it was taken up seriously as a technique for integrated circuit (IC) testing. While ICs were being fabricated on design rules of several microns, the mechanical ne edle probe served quite adequately for internal chip probing. This scenario changed with growing device complexity and shrinking geometries, prompting IC manufacturers to take note ofthis new testing technology. It required several more years and considerable investment by electron beam tester manufacturers, however, to co me up with user-friendly automated systems that were acceptable to IC test engineers. These intervening years witnessed intense activity in the development of instrumentation, testing techniques, and system automation, as evidenced by the proliferation of technical papers presented at conferences. With the shift of interest toward applications, the technology may now be considered as having come of age.

Brilliant Light in Life and Material Sciences

Brilliant Light in Life and Material Sciences PDF Author: Vasili Tsakanov
Publisher: Springer Science & Business Media
ISBN: 1402057229
Category : Medical
Languages : en
Pages : 484

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Book Description
This book contains an excellent overview of the status and highlights of brilliant light facilities and their applications in biology, chemistry, medicine, materials and environmental sciences. Overview papers on diverse fields of research by leading experts are accompanied by the highlights in the near and long-term perspectives of brilliant X-Ray photon beam usage for fundamental and applied research.

Beam Diagnostics in Superconducting Accelerating Cavities

Beam Diagnostics in Superconducting Accelerating Cavities PDF Author: Pei Zhang
Publisher: Springer Science & Business Media
ISBN: 3319007599
Category : Science
Languages : en
Pages : 128

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Book Description
An energetic charged particle beam introduced to an rf cavity excites a wakefield therein. This wakefield can be decomposed into a series of higher order modes and multipoles, which for sufficiently small beam offsets are dominated by the dipole component. This work focuses on using these dipole modes to detect the beam position in third harmonic superconducting S-band cavities for light source applications. A rigorous examination of several means of analysing the beam position based on signals radiated to higher order modes ports is presented. Experimental results indicate a position resolution, based on this technique, of 20 microns over a complete module of 4 cavities. Methods are also indicated for improving the resolution and for applying this method to other cavity configurations. This work is distinguished by its clarity and potential for application to several other international facilities. The material is presented in a didactic style and is recommended both for students new to the field, and for scientists well-versed in the field of rf diagnostics.