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Related papers: Emittance Mapping in rf Guns

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Numerical and semi-analytical models are presented for photon-enhanced-thermionic-emission (PETE) devices. The models take diffusion of electrons, inhomogeneous photogeneration, and bulk and surface recombination into account. The…

Materials Science · Physics 2012-08-27 Aapo Varpula , Mika Prunnila

The characteristics of the Galactic Center Excess (GCE) emission observed in gamma-ray energies -- especially the morphology of the GCE -- remain a hotly debated subject. The manner in which the dominant diffuse gamma-ray background is…

High Energy Astrophysical Phenomena · Physics 2023-10-10 Samuel D. McDermott , Yi-Ming Zhong , Ilias Cholis

We investigate the limits of photoemission yield in a high-gradient S-band radiofrequency photoinjector in the space-charge-dominated regime. Using an RF phase-scan technique, where the emitted charge is measured as a function of the…

Methodologies for characterization of the lateral indentation of silicon-germanium (SiGe) nanosheets using different non-destructive and in-line compatible metrology techniques are presented and discussed. Gate-all-around nanosheet device…

Transverse instability of a bunched beam is investigated with synchrotron oscillations, space charge, and resistive wall wakefield taken into account. Boxcar model is used for all-round analysis, and Gaussian distribution is invoked for…

Accelerator Physics · Physics 2012-01-25 V. Balbekov

Within the internal shock scenario we consider different mechanisms of high energy ($>1$ MeV) photon production inside a Gamma Ray Burst (GRB) fireball and derive the expected high energy photon spectra from individual GRBs during the…

Astrophysics · Physics 2009-06-23 Nayantara Gupta , Bing Zhang

Time-resolved multi-terahertz (THz) spectroscopy is used to observe an ultrafast, non-thermal electronic phase change in SnSe driven by interband photoexcitation with 1.55 eV pump photons. The transient THz photoconductivity spectrum is…

Materials Science · Physics 2024-02-12 Benjamin J. Dringoli , Mark Sutton , Zhongzhen Luo , Mercouri G. Kanatzidis , David G. Cooke

The square of the horizontal projected (rms) beam emittance is expressed as the sum of four nonnegative contributions, each described using the slice moments of the beam and possessing a natural interpretation in terms of the geometrical…

Accelerator Physics · Physics 2015-09-17 Chad Mitchell

We present accurate analytic fitting formulae for the frequency integrated Gaunt factors for the relativistic as well as nonrelativistic thermal bremsstrahlung which is relevant to the intracluster plasma. The fitting is carried out for 1…

Astrophysics · Physics 2007-07-31 Naoki Itoh , Shugo Kusano , Tsuyoshi Sakamoto , Satoshi Nozawa

The theory of cold, relativistic, magnetohydrodynamic outflows is generalized by the inclusion of an intense radiation source. In some contexts, such the breakout of a gamma-ray burst jet from a star, the outflow is heated to a high…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Matthew Russo , Christopher Thompson

We review known and discuss new signatures of high-intensity Compton scattering assuming a scenario where a high-power laser is brought into collision with an electron beam. At high intensities one expects to see a substantial red-shift of…

High Energy Physics - Phenomenology · Physics 2010-04-21 Chris Harvey , Thomas Heinzl , Anton Ilderton

The Fermi Gamma-Ray Space Telescope reveals a diffuse inverse Compton signal in the inner Galaxy with a similar spatial morphology to the microwave haze observed by WMAP, supporting the synchrotron interpretation of the microwave signal.…

High Energy Astrophysical Phenomena · Physics 2010-11-10 Gregory Dobler , Douglas P. Finkbeiner , Ilias Cholis , Tracy R. Slatyer , Neal Weiner

Space-charge-induced emittance growth is a big con-cern for designing low energy and high intensity linacs. The Equipartitioning Principle was introduced to mini-mize space-charge-induced emittance growth by remov-ing free energy between…

Accelerator Physics · Physics 2021-05-18 Chuan Zhang

Dedicated optics with extremely short electron bunches enable synchrotron light sources to generate intense coherent THz radiation. The high degree of spatial compression in this so-called low-alpha optics entails a complex longitudinal…

We have developed a novel method based on vector electromagnetic theory and Schellkunoff's principles to calculate the spectral and angular distributions of transtion radiation (TR) and diffraction radiation (DR) produced by a charged…

Accelerator Physics · Physics 2008-11-26 A. G. Shkvarunets , R. B. Fiorito

There is a robust upper limit on the energy of synchrotron radiation in high-energy astrophysics: $ \sim m_{\rm e} c^2 /\alpha$, where $\alpha = 1/137$ is the fine structure constant and the value refers to the comoving frame of the fluid.…

Astrophysics · Physics 2015-05-13 Boris E. Stern , Yana Y. Tikhomirov

This manuscript presents, to our knowledge, the first fully ab initio many-body photoemission framework to predict the transverse momentum distributions and the mean transverse energies (MTEs) of photoelectrons from single-crystal…

The observations of TeV blazars published recently show an unexpected quadratic or even cubic correlation between the X-ray and gamma-ray emission. A standard model of the synchrotron self-Compton emission of a compact source inside a jet…

High Energy Astrophysical Phenomena · Physics 2015-05-14 K. Katarzynski , K. Walczewska

In this contribution to Light Cone 2014, three average transverse momentum quantities are discussed: the Sivers shift, the dijet imbalance, and the $p_T$ broadening. The definitions of these quantities involve integrals over all transverse…

High Energy Physics - Phenomenology · Physics 2015-06-23 Daniel Boer

The inhomogeneous brightness distribution of BATSE detected gamma-ray bursts has been considered strong evidence for their cosmological origin. However, subclasses of gamma-ray bursts have been shown to have significantly more homogeneous…

Astrophysics · Physics 2007-05-23 J. T. Bonnell , J. P. Norris
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