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Related papers: Seeding of Self-Modulation using Truncated Seed Bu…

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Alternating minimization methods have recently been proposed as alternatives to the gradient descent for deep neural network optimization. Alternating minimization methods can typically decompose a deep neural network into layerwise…

Machine Learning · Computer Science 2020-09-18 Junxiang Wang , Zheng Chai , Yue Cheng , Liang Zhao

Motivated by recent experiments, we study four-wave-mixing in an atomic double-{\Lambda} system driven by a far-detuned pump. Using the Heisenberg-Langevin formalism, and based on the microscopic properties of the medium, we calculate the…

Quantum Physics · Physics 2015-05-19 Q. Glorieux , R. Dubessy , S. Guibal , L. Guidoni , J. P. Likforman , T. Coudreau , E. Arimondo

Seed area generation is usually the starting point of weakly supervised semantic segmentation (WSSS). Computing the Class Activation Map (CAM) from a multi-label classification network is the de facto paradigm for seed area generation, but…

Computer Vision and Pattern Recognition · Computer Science 2023-09-01 Zelin Peng , Guanchun Wang , Lingxi Xie , Dongsheng Jiang , Wei Shen , Qi Tian

We show in experiments that a long, relativistic proton bunch is focused by the plasma adiabatic response. The free plasma electrons migrate so as to neutralize the space charge field of the bunch, and the bunch is therefore focused by the…

Accelerator Physics · Physics 2022-08-29 L. Verra , E. Gschwendtner , P. Muggli

We present an analytically solvable model for self-assembly of a molecular complex on a filament. The process is driven by a seed molecule that undergoes facilitated diffusion, which is a search strategy that combines diffusion in…

Statistical Mechanics · Physics 2015-11-04 Ziya Kalay

We presented a novel concept of longitudinal bunch train compression capable of manipulating relativistic electron beam in range of hundreds of meters. This concept has the potential to compress the electron beam generated by conditional…

Accelerator Physics · Physics 2023-06-16 An Li , Jiaru Shi , Hao Zha , Qiang Gao , Liuyuan Zhou , Huaibi Chen

Experimental results, supported by precise modelling, demonstrate optimisation of a plasma-based injector with intermediate laser pulse energy ($<1$ J), corresponding to a normalised vector potential $a_0 = 2.15$, using ionisation injection…

Bunch splitting is an RF manipulation method of changing the bunch structure, bunch numbers and bunch intensity in the high-intensity synchrotrons that serve as the injector for a particle collider. An efficient way to realize bunch…

Accelerator Physics · Physics 2021-02-05 Linhao Zhang , Min Chen , Jingyu Tang

Simulations are widely used to study nucleation in first order phase transitions due to the fact that they have access to the relevant length and time scales. However, simulations face the problem that nucleation is an activated process.…

Soft Condensed Matter · Physics 2020-03-06 Pablo Rosales-Pelaez , Ignacio Sanchez-Burgos , Chantal Valeriani , Carlos Vega , Eduardo Sanz

Relativistic wakes produced by intense laser or particle beams propagating through plasmas are being considered as accelerators for next generation of colliders and coherent light sources. Such wakes have been shown to accelerate electrons…

Plasma Physics · Physics 2016-10-19 C. J. Zhang , J. F. Hua , Y. Wan , B. Guo , Y. P. Wu , C. -H. Pai , F. Li , H. -H. Chu , Y. Q. Gu , X. L. Xu , W. B. Mori , C. Joshi , J. Wang , W. Lu

Direct numerical simulations of electrospinning and electrospraying are computationally demanding due to large-scale separation between the needle and the tip-to-collector distance. The cone-jet mode that occurs in the vicinity of the…

Fluid Dynamics · Physics 2026-02-18 Ghanashyam K. C. , Satyavrata Samavedi , Harish N Dixit

Plasma wakefield acceleration, either laser driven or electron-bunch driven, has been demonstrated to hold great potential. However, it is not obvious how to scale these approaches to bring particles up to the TeV regime. In this paper, we…

Accelerator Physics · Physics 2015-05-13 Allen Caldwell , Konstantin Lotov , Alexander Pukhov , Frank Simon

We study the evolution of the self-modulation instability using bunches with finite rise times. Using particle-in-cell simulations we show that unlike long bunches with sharp rise times, there are large variations of the wake amplitudes and…

Plasma Physics · Physics 2014-09-16 J. Vieira , L. D. Amorim , Y. Fang , W. B. Mori , P. Muggli , L. O. Silva

The objective of this paper is to investigate a new numerical method for the approximation of the self-diffusion matrix of a tagged particle process defined on a grid. While standard numerical methods make use of long-time averages of…

Numerical Analysis · Mathematics 2023-02-27 Jad Dabaghi , Virginie Ehrlacher , Christoph Strössner

Distributed stochastic optimization algorithms can simultaneously process large-scale datasets, significantly accelerating model training. However, their effectiveness is often hindered by the sparsity of distributed networks and data…

Machine Learning · Computer Science 2025-02-14 Yuchen Hu , Xi Chen , Weidong Liu , Xiaojun Mao

A new scheme of proton acceleration from a laser-driven near-critical-density plasma is proposed. Plasma with a tailored density profile allows a two-stage acceleration of protons. The protons are pre-accelerated in the laser-driven…

Plasma Physics · Physics 2019-02-13 Y. Wan , I. A. Andriyash , J. F. Hua , C. -H. Pai , W. Lu , W. B. Mori , C. Joshi , V. Malka

In the Phase 2 of the AWAKE first experimental run (from May to November 2018), an electron beam was used to probe and test proton-driven wakefield acceleration in a rubidium plasma column. In this work, we analyze the overall charge…

A magnetic spectrometer has been developed for the AWAKE experiment at CERN in order to measure the energy distribution of bunches of electrons accelerated in wakefields generated by proton bunches in plasma. AWAKE is a proof-of-principle…

Equilibrium bunch lengths typical to modern day light sources of tens of picoseconds limit the spectral reach of superradiant approaches for exploring materials and biological samples. In particular, generation of terahertz radiation seems…

Accelerator Physics · Physics 2023-05-01 Sergey A. Antipov , Ilya Agapov , Igor Zagorodnov , Francois Lemery