scholarly journals A cloud-chamber investigation of penetrating showers

1946 ◽  
Vol 187 (1011) ◽  
pp. 464-479 ◽  
Keyword(s):  
Small Groups ◽  
Meson Production ◽  
High Energy ◽  
Cloud Chamber ◽  
Meson Spectrum ◽  
High Energy Electron ◽  
High Energies ◽  
Incident Nucleon ◽  
Very High ◽  
Counter Data

An account is given of a cloud-chamber investigation of penetrating showers. It is concluded that the cloud-chamber data are consistent with Jánossy’s counter data and also with the view that penetrating showers consist of a small number of penetrating ionizing particles which are mainly mesons. There is no evidence to show that the showers are produced by processes other than those postulated in the theory of meson production proposed by Hamilton, Heitler & Peng, together with the addition suggested by Jánossy, i. e. the emission of small groups of mesons every few centimetres of lead. There are given several photographs of showers of penetrating particles which may be examples of the successive production of penetrating particles by an incident nucleon and its recoil particles. The spectrum of the penetrating particles seems to be approximately of the same form as the meson spectrum at sea-level. Some 20% of penetrating showers are accompanied, in the cloud chamber, by what appear to be electron cascades. It is shown that these showers cannot be due to knock-on electrons, to high-energy electron cascades penetrating the whole thickness of the absorber, or to decay electrons unless a meson of lifetime less than 10 -10 sec. is postulated. It is suggested that these showers may be due to electrons or photons produced in processes which become important at very high energies, e. g. > 10 11 eV.

scholarly journals Focused VHEE (very high energy electron) beams and dose delivery for radiotherapy applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
L. Whitmore ◽  
R. I. Mackay ◽  
M. van Herk ◽  
J. K. Jones ◽  
R. M. Jones
Keyword(s):  
Electron Beams ◽  
Focal Point ◽  
External Beam Radiotherapy ◽  
High Energy ◽  
Energy Electron ◽  
High Energy Electron ◽  
Dose Delivery ◽  
Entrance Dose ◽  
Very High Energy ◽  
Very High

AbstractThis paper presents the first demonstration of deeply penetrating dose delivery using focused very high energy electron (VHEE) beams using quadrupole magnets in Monte Carlo simulations. We show that the focal point is readily modified by linearly changing the quadrupole magnet strength only. We also present a weighted sum of focused electron beams to form a spread-out electron peak (SOEP) over a target region. This has a significantly reduced entrance dose compared to a proton-based spread-out Bragg peak (SOBP). Very high energy electron (VHEE) beams are an exciting prospect in external beam radiotherapy. VHEEs are less sensitive to inhomogeneities than proton and photon beams, have a deep dose reach and could potentially be used to deliver FLASH radiotherapy. The dose distributions of unfocused VHEE produce high entrance and exit doses compared to other radiotherapy modalities unless focusing is employed, and in this case the entrance dose is considerably improved over existing radiations. We have investigated both symmetric and asymmetric focusing as well as focusing with a range of beam energies.

scholarly journals Concept of generation of extremely compressed high-energy electron bunches in several interfering intense laser pulses with tilted amplitude fronts

2012 ◽  
Vol 31 (1) ◽  
pp. 23-28 ◽  
Author(s):  
V.V. Korobkin ◽  
M.Yu. Romanovskiy ◽  
V.A. Trofimov ◽  
O.B. Shiryaev
Keyword(s):  
Laser Pulses ◽  
High Energy ◽  
Intense Laser ◽  
High Energy Electron ◽  
Speed Of Light ◽  
Electron Bunches ◽  
Newton Equation ◽  
High Energies ◽  
Neutral Gas ◽  
Intense Laser Pulses

AbstractA new concept of generating tight bunches of electrons accelerated to high energies is proposed. The electrons are born via ionization of a low-density neutral gas by laser radiation, and the concept is based on the electrons acceleration in traps arising within the pattern of interference of several relativistically intense laser pulses with amplitude fronts tilted relative to their phase fronts. The traps move with the speed of light and (1) collect electrons; (2) compress them to extremely high density in all dimensions, forming electron bunches; and (3) accelerate the resulting bunches to energies of at least several GeV per electron. The simulations of bunch formation employ the Newton equation with the corresponding Lorentz force.

scholarly journals Assessment of the quality of very high-energy electron radiotherapy planning

2016 ◽  
Vol 119 (1) ◽  
pp. 154-158 ◽  
Author(s):  
Bianey Palma ◽  
Magdalena Bazalova-Carter ◽  
Björn Hårdemark ◽  
Elin Hynning ◽  
Bradley Qu ◽  
...  
Keyword(s):  
High Energy ◽  
Energy Electron ◽  
Radiotherapy Planning ◽  
High Energy Electron ◽  
Very High Energy ◽  
Electron Radiotherapy ◽  
Very High

scholarly journals High-energy emission from gamma-ray bursts

2018 ◽  
Vol 27 (13) ◽  
pp. 1842003 ◽  
Author(s):  
Lara Nava
Keyword(s):  
Gamma Ray ◽  
Theoretical Models ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
Quality Of Data ◽  
Large Area ◽  
High Energies ◽  
Energy Emission ◽  
High Energy Emission ◽  
Very High

The number of gamma-ray bursts (GRBs) detected at high energies ([Formula: see text][Formula: see text]GeV) has seen a rapid increase over the last decade, thanks to observations from the Fermi-Large Area Telescope. The improved statistics and quality of data resulted in a better characterization of the high-energy emission properties and in stronger constraints on theoretical models. In spite of the many achievements and progresses, several observational properties still represent a challenge for theoretical models, revealing how our understanding is far from being complete. This paper reviews the main spectral and temporal properties of [Formula: see text][Formula: see text]GeV emission from GRBs and summarizes the most promising theoretical models proposed to interpret the observations. Since a boost for the understanding of GeV radiation might come from observations at even higher energies, the present status and future prospects for observations at very-high energies (above [Formula: see text][Formula: see text]100[Formula: see text]GeV) are also discussed. The improved sensitivity of upcoming facilities, coupled to theoretical predictions, supports the concrete possibility for future ground GRB detections in the high/very-high energy domain.

SU-E-T-274: Radiation Therapy with Very High-Energy Electron (VHEE) Beams in the Presence of Metal Implants

2014 ◽  
Vol 41 (6Part15) ◽  
pp. 286-287 ◽  
Author(s):  
C Jensen ◽  
B Palma ◽  
B Qu ◽  
P Maxim ◽  
B Hardemark ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
High Energy ◽  
Energy Electron ◽  
High Energy Electron ◽  
Metal Implants ◽  
Very High Energy ◽  
Very High

scholarly journals Monitoring the Extragalactic High Energy Sky

Galaxies ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 9 ◽  
Author(s):  
Jean-Philippe Lenain
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
High Energy ◽  
Line Of Sight ◽  
Data Sets ◽  
High Energies ◽  
Multi Wavelength ◽  
Rich Data ◽  
Very High

Blazars are jetted active galactic nuclei with a jet pointing close to the line of sight, hence enhancing their intrinsic luminosity and variability. Monitoring these sources is essential in order to catch them flaring and promptly organize follow-up multi-wavelength observations, which are key to providing rich data sets used to derive e.g., the emission mechanisms at work, and the size and location of the flaring zone. In this context, the Fermi-LAT has proven to be an invaluable instrument, whose data are used to trigger many follow-up observations at high and very high energies. A few examples are illustrated here, as well as a description of different data products and pipelines, with a focus given on FLaapLUC, a tool in use within the H.E.S.S. collaboration.

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