1S-A1-2Innovate Electron Beam by GaN Semiconductor Photocathodes Conducive to Single Shot Imaging

Microscopy ◽  
2017 ◽  
Vol 66 (suppl_1) ◽  
pp. i6-i6
Author(s):  
Tomohiro Nishitani ◽  
Akihiro Narita ◽  
Takeshi Tomita ◽  
Shin-ichi Kitamura ◽  
Takashi Meguro ◽  
...  
Keyword(s):  
Electron Beam ◽  
Single Shot

scholarly journals Control of the Longitudinal Compression and Transverse Focus of Ultrafast Electron Beam for Detecting the Transient Evolution of Materials

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 571
Author(s):  
Xintian Cai ◽  
Zhen Wang ◽  
Chaoyue Ji ◽  
Xuan Wang ◽  
Zhiyin Gan ◽  
...  
Keyword(s):  
Electron Beam ◽  
Temporal Resolution ◽  
Fast Electron ◽  
Single Pulse ◽  
Coulomb Force ◽  
Single Shot ◽  
Longitudinal Compression ◽  
Rf Cavity ◽  
Tracking Model ◽  
The Impact

Ultrafast detection is an effective method to reveal the transient evolution mechanism of materials. Compared with ultra-fast X-ray diffraction (XRD), the ultra-fast electron beam is increasingly adopted because the larger scattering cross-section is less harmful to the sample. The keV single-shot ultra-fast electron imaging system has been widely used with its compact structure and easy integration. To achieve both the single pulse imaging and the ultra-high temporal resolution, magnetic lenses are typically used for transverse focus to increase signal strength, while radio frequency (RF) cavities are generally utilized for longitudinal compression to improve temporal resolution. However, the detection signal is relatively weak due to the Coulomb force between electrons. Moreover, the effect of RF compression on the transverse focus is usually ignored. We established a particle tracking model to simulate the electron pulse propagation based on the 1-D fluid equation and the 2-D mean-field equation. Under considering the relativity effect and Coulomb force, the impact of RF compression on the transverse focus was studied by solving the fifth-order Rung–Kutta equation. The results show that the RF cavity is not only a key component of longitudinal compression but also affects the transverse focusing. While the effect of transverse focus on longitudinal duration is negligible. By adjusting the position and compression strength of the RF cavity, the beam spot radius can be reduced from 100 μm to 30 μm under the simulation conditions in this paper. When the number of single pulse electrons remains constant, the electrons density incident on the sample could be increased from 3.18×1012 m−2 to 3.54×1013 m−2, which is 11 times the original. The larger the electron density incident on the sample, the greater the signal intensity, which is more conducive to detecting the transient evolution of the material.

scholarly journals Toward monochromated sub-nanometer UEM and femtosecond UED

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Xi Yang ◽  
Weishi Wan ◽  
Lijun Wu ◽  
Victor Smaluk ◽  
Timur Shaftan ◽  
...  
Keyword(s):  
Electron Beam ◽  
Real Time ◽  
Beam Energy ◽  
Path Length ◽  
Energy Spread ◽  
Single Shot ◽  
Accumulation Mode ◽  
Length Difference ◽  
Path Length Difference ◽  
Energy Dependent

Abstract A preliminary design of a mega-electron-volt (MeV) monochromator with 10−5 energy spread for ultrafast electron diffraction (UED) and ultrafast electron microscopy (UEM) is presented. Such a narrow energy spread is advantageous in both the single shot mode, where the momentum resolution in diffraction is improved, and the accumulation mode, where shot-to-shot energy jitter is reduced. In the single-shot mode, we numerically optimized the monochromator efficiency up to 13% achieving 1.3 million electrons per pulse. In the accumulation mode, to mitigate the efficiency degradation caused by the shot-to-shot energy jitter, an optimized gun phase yields only a mild reduction of the single-shot efficiency, therefore the number of accumulated electrons nearly proportional to the repetition rate. Inspired by the recent work of Qi et al. (Phys Rev Lett 124:134803, 2020), a novel concept of applying reverse bending magnets to adjust the energy-dependent path length difference has been successfully realized in designing a MeV monochromator to achieve the minimum energy-dependent path length difference between cathode and sample. Thanks to the achromat design, the pulse length of the electron bunches and the energy-dependent timing jitter can be greatly reduced to the 10 fs level. The introduction of such a monochromator provides a major step forward, towards constructing a UEM with sub-nm resolution and a UED with ten-femtosecond temporal resolution. The one-to-one mapping between the electron beam parameter and the diffraction peak broadening enables a real-time nondestructive diagnosis of the beam energy spread and divergence. The tunable electric–magnetic monochromator allows the scanning of the electron beam energy with a 10−5 precision, enabling online energy matching for the UEM, on-momentum flux maximizing for the UED and real-time energy measuring for energy-loss spectroscopy. A combination of the monochromator and a downstream chicane enables “two-color” double pulses with femtosecond duration and the tunable delay in the range of 10 to 160 fs, which can potentially provide an unprecedented femtosecond time resolution for time resolved UED.

Bunched electron beam properties measurement by means of single-shot multibeam cross-correlation technique

2006 ◽  
Vol 53 (7) ◽  
pp. 919-929 ◽  
Author(s):  
V. O. Chaltikyan ◽  
D. L. Hovhannisyan ◽  
E. M. Laziev ◽  
A. O. Melikyan ◽  
A. O. Vardanyan
Keyword(s):  
Electron Beam ◽  
Cross Correlation ◽  
Correlation Technique ◽  
Single Shot ◽  
Cross Correlation Technique

scholarly journals Accurate prediction of mega-electron-volt electron beam properties from UED using machine learning

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhe Zhang ◽  
Xi Yang ◽  
Xiaobiao Huang ◽  
Junjie Li ◽  
Timur Shaftan ◽  
...  
Keyword(s):  
Machine Learning ◽  
Electron Beam ◽  
Real Time ◽  
Repetition Rate ◽  
High Repetition Rate ◽  
Detailed Knowledge ◽  
Full Potential ◽  
Single Shot ◽  
Noninvasive Diagnostics ◽  
High Repetition

AbstractTo harness the full potential of the ultrafast electron diffraction (UED) and microscopy (UEM), we must know accurately the electron beam properties, such as emittance, energy spread, spatial-pointing jitter, and shot-to-shot energy fluctuation. Owing to the inherent fluctuations in UED/UEM instruments, obtaining such detailed knowledge requires real-time characterization of the beam properties for each electron bunch. While diagnostics of these properties exist, they are often invasive, and many of them cannot operate at a high repetition rate. Here, we present a technique to overcome such limitations. Employing a machine learning (ML) strategy, we can accurately predict electron beam properties for every shot using only parameters that are easily recorded at high repetition rate by the detector while the experiments are ongoing, by training a model on a small set of fully diagnosed bunches. Applying ML as real-time noninvasive diagnostics could enable some new capabilities, e.g., online optimization of the long-term stability and fine single-shot quality of the electron beam, filtering the events and making online corrections of the data for time-resolved UED, otherwise impossible. This opens the possibility of fully realizing the potential of high repetition rate UED and UEM for life science and condensed matter physics applications.

scholarly journals Electron Beam Sources using InGaN Semiconductor Photocathodes for Single-shot Imaging Electron Microscope

2017 ◽  
Vol 23 (S1) ◽  
pp. 808-809
Author(s):  
Tomohiro Nishitani ◽  
Akihiro Narita ◽  
Takeshi Tomita ◽  
Shin-ichi Kitamura ◽  
Takashi Meguro ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Single Shot

20 MeV QUASI-MONOENERGETIC ELECTRON BEAM PRODUCTION BY USING JLITE-X LASER SYSTEM AT JAEA-APRC

2007 ◽  
Vol 21 (03n04) ◽  
pp. 407-414
Author(s):  
M. MORI ◽  
M. KANDO ◽  
I. DAITO ◽  
H. KOTAKI ◽  
Y. HAYASHI ◽  
...  
Keyword(s):  
Electron Beam ◽  
Laser System ◽  
Experimental Studies ◽  
Forward Direction ◽  
Particle Accelerators ◽  
Single Shot ◽  
Monoenergetic Electron ◽  
Beam Production ◽  
Peak Energy ◽  
Monoenergetic Electron Beam

We have developed a multi-terawatt Ti :Sapphire laser system to study on the laser driven particle accelerators. We have also developed a relevant instruments that contains a pointing stabilizer and single-shot selector to perform a lot of experimental studies. After development, we are studying on the electron acceleration. A quasi-monoenergetic electron beam is observed in the forward direction. The peak energy of a quasi-monoenergetic component of the electron beam is 20 MeV with a energy spread of 20% at the plasma density of 4.7 × 1019cm-3. The table-top laser driven fs quasi-monoenergetic electron beam which is applicable to variety of fields is described.

scholarly journals Single-shot divergence measurements of a laser-generated relativistic electron beam

2010 ◽  
Vol 17 (11) ◽  
pp. 113106 ◽  
Author(s):  
F. Perez ◽  
S. D. Baton ◽  
M. Koenig ◽  
C. D. Chen ◽  
D. Hey ◽  
...  
Keyword(s):  
Electron Beam ◽  
Relativistic Electron ◽  
Relativistic Electron Beam ◽  
Single Shot

Single-Shot Electron-Beam Bunch Length Measurements

2002 ◽  
Vol 88 (12) ◽  
Author(s):  
I. Wilke ◽  
A. M. MacLeod ◽  
W. A. Gillespie ◽  
G. Berden ◽  
G. M. H. Knippels ◽  
...  
Keyword(s):  
Electron Beam ◽  
Bunch Length ◽  
Single Shot ◽  
Length Measurements

Single shot non-perturbative electron beam characterization with a microwiggler

1998 ◽  
pp. II-111-II-112
Author(s):  
P. Catravas ◽  
M. Babzien ◽  
I. Ben-Zvi ◽  
Z. Segalov ◽  
X.-J. Wang ◽  
...  
Keyword(s):  
Electron Beam ◽  
Single Shot ◽  
Beam Characterization

scholarly journals Ultrarelativistic Electron-Beam Polarization in Single-Shot Interaction with an Ultraintense Laser Pulse

2019 ◽  
Vol 122 (15) ◽  
Author(s):  
Yan-Fei Li ◽  
Rashid Shaisultanov ◽  
Karen Z. Hatsagortsyan ◽  
Feng Wan ◽  
Christoph H. Keitel ◽  
...  
Keyword(s):  
Electron Beam ◽  
Laser Pulse ◽  
Beam Polarization ◽  
Single Shot ◽  
Ultrarelativistic Electron
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