Expected Results From Channeling Radiation Experiments at Fast

Quantum Aspects of Beam Physics - 18th Advanced ICFA Beam Dynamics Workshop, 2002

Plasmas offer the possibility of high acceleration gradients. An intriguing suggestion is to use the higher plasma densities possible in solids to get extremely high gradients. Although solid state plasmas might produce high gradients they would pose daunting problems. Crystal channeling has been suggested as one mechanism to address these challenges. There is no experimental or theoretical guidance on channeling in intense electron and laser beams. A high density plasma in a crystal lattice could quench the channeling process. An experiment is being carried out at the Fermilab A0 Photo-Injector Test Facility to observe electron channeling radiation at high bunch charges. An electron beam with up to 8 nC per electron bunch has been used to investigate the electron-crystal interaction. No evidence has been found of significant quenching of channeling at charge densities several orders of magnitude larger than in earlier experiments.

In this contribution we describe the technical details and experimental setup toward the production of highbrightness channeling radiation (CR) at the Fermilab's Advanced Superconducting Test Accelerator (ASTA). In the ASTA photoinjector area electrons are accelerated up to 40-MeV and focused to a sub-micron spot on a 168 micron thick carbon diamond, the electrons channel through the crystal and emit CR up to 80-KeV. Our study utilizes ASTA's long pulse train capabilities and ability to preserve ultra-low emittance, to produce the desired brightness.

Nukleonika, 2016

The paper reports results of the recent experimental studies of pulsed electron beams and soft X-rays in plasma-focus (PF) experiments carried out within a modified PF-360U facility at the NCBJ, Poland. Particular attention was focused on time-resolved measurements of the fast electron beams by means of two different magnetic analyzers, which could record electrons of energy ranging from about 41 keV to about 715 keV in several (6 or 8) measuring channels. For discharges performed with the pure deuterium filling, many strong electron signals were recorded in all the measuring channels. Those signals were well correlated with the first hard X-ray pulse detected by an external scintillation neutron-counter. In some of the analyzer channels, electron spikes (lasting about dozens of nanoseconds) and appearing in different instants after the current peculiarity (so-called current dip) were also recorded. For several discharges, fast ion beams, which were emitted along the z-axis and reco...

2017

The positron source under investigation is using channeling radiation of multi-GeV electrons in a tungsten crystal. The radiated photons are impinging on the amorphous targets creating e+e− pairs. A dipole magnet between the crystalradiator and the amorphous-converter allows the charged particles to be swept off and only emitted photons to generate e+e− pairs in the converter. Granular targets of different thicknesses, made of small tungsten spheres, have been recently investigated as a target-converter. This paper is describing the experimental studies conducted at the KEKB linac with such device. After the description of the experimental set-up and beam parameters, the measurement methods and preliminary results are presented.

1997

The Advanced Laser-Plasma High-Energy Accelerators towards X-rays (ALPHA-X) programme at the University of Strathclyde is developing laser-plasma wakefield accelerators to produce high energy, ultra-short duration electron bunches as drivers of radiation sources. Coherent emission will be produced in a free-electron laser by focussing the ultra-short electron bunches into an undulator. To achieve net gain, high peak current, low energy spread and low emittance are required. A high intensity, ultra-short pulse from a 30 TW Ti:sapphire laser is focussed into a helium gas jet to produce femtosecond duration electron bunches in the range of 80 -200 MeV. Beam transport is monitored using a series of Lanex screens positioned along the beam line.

2007

Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2003

The Photo Injector Test facility at DESY Zeuthen (PITZ) was built to develop electron sources for the TESLA Test Facility Free Electron Laser (TTF-FEL) and future linear colliders. The main goal is to study the production of minimum transverse emittance beams with short bunch length at medium charge (~1nC). The facility includes a 1.5 cell L-band cavity with coaxial rf coupler, a solenoid for space charge compensation, a laser capable to generate long pulse trains, an UHV photo cathode exchange system, and different diagnostics tools. Besides an overview of the facility, its main components and their commissioning, this contribution will concentrate on the first measurements at PITZ with photo electrons. This will include measurements of the transverse and longitudinal laser profile, charge and quantum efficiency, momentum and momentum spread, transverse electron beam profiles at different locations and first results on transverse emittance. PACS codes: 29.25 Bx electron sources, 29.27 Fh beam characteristics, 41.60 Cr Free electron Laser, 41.75 Fr electron and positron beam, 41.85 Ew beam profile

2008

The DAFNE Beam Test Facility (BTF) is in operation since the 2003 and has been continuously improved and upgraded in order to take into account the many different requests coming from the high energy and accelerator community. The facility was initially optimized to produce single electron and positron in the 25-750 MeV energy rage, manly for high energy detector calibration and testing; it can now provide beam in a wider range of intensity, up to 10^10 electrons/sec, typically needed for accelerator diagnostic tests. In the last two years the facility has also been modified in order to produce tagged photons, and the possibility to deliver tagged neutrons in the MeV energy range is under study. The main results obtained, the performance and the most significant characteristics of the facility diagnostics and operation are presented, as well as the users experience collected during these years of operation.

Proceedings of the 2003 Bipolar/BiCMOS Circuits and Technology Meeting (IEEE Cat. No.03CH37440)