Search results for "Linear particle accelerator"

Spinrotator for MAMI

1991

A source of polarized electrons based on the photoemission of a GaAsP-cathode [1] has been set up to inject polarized electrons in the Mainz microtron MAMI. In order to compensate the spin precession in MAMI a spinrotator system has to be integrated in the 100 keV beamline from the source to the injector linac to achieve the required longitudinal spin direction at target position.

INVESTIGATION OF FAR-INFRARED SMITH-PURCELL RADIATION AT THE 3.41 MEV ELECTRON INJECTOR LINAC OF THE MAINZ MICROTRON MAMI

2006

Photonuclear reactions induced by a clinical linac

2015

1st NUBA International Conference on Nuclear Physics and Astrophysics -- SEP 14-21, 2014 -- Akdeniz Univ, Antalya, TURKEY

Die elektronenstreu-apparatur am mainzer 300 MeV-elektronen-linearbeschleuniger

1972

Abstract In this paper, we attempt to give a general survey and a comprehensive description of the most significant features of the facilities for electron scattering experiments at the Mainz 300 MeV Linear Accelerator, along with a list of literature, where more detailed information on certain subjects can be found. The accelerator provides energies between 80 and 300 MeV. Scattering angles are available up to 160° resulting in a momentum transfer region up to 3.0 fm −1 . The overall experimental resolution is 0.1%. Cross sections down to 10 −34 cm 2 /sr can be measured. The main features of the apparatus are: an achromatic magnet system with 90° deflection, a double focusing spectrometer,…

Experimental investigations of backward transition radiation characteristics in extreme ultraviolet region

2011

ABSTRACT This report summarizes the results of an experiment dedicated to the observation of backward transition radia-tion in the EUV spectral region. This radiation was ge nerated by an 855MeV electron beam at a molybdenumtarget. The radiation characteristics in the EUV region are compared to those in the optical region. It wasshown that the radiation measured in the EUV region was more intense than theoretically predicted. As aresult the EUV radiation yield seems to be suci ent for standard beam pro“le diagnostics.Keywords: EUV, Transition radiation, Beam diagnostics 1. INTRODUCTION Transverse pro“le diagnostics in mo dern electron linear accelerators as F ELs or injector linacs is mainl…

Experimental validation of a novel compact focusing scheme for future energy-frontier linear lepton colliders.

2014

A novel scheme for the focusing of high-energy leptons in future linear colliders was proposed in 2001 [ P. Raimondi and A. Seryi , Phys. Rev. Lett. 86 , 3779 ( 2001 ) ]. This scheme has many advantageous properties over previously studied focusing schemes, including being significantly shorter for a given energy and having a significantly better energy bandwidth. Experimental results from the ATF2 accelerator at KEK are presented that validate the operating principle of such a scheme by demonstrating the demagnification of a 1.3 GeV electron beam down to below 65 nm in height using an energy-scaled version of the compact focusing optics designed for the ILC collider.

Comparison between transmission and scattering spectrum reconstruction methods based on EPID images.

2013

Numerous improved physics-based methods for Linac photon spectra reconstruction have been published; some of them are based on transmission data analysis and others on scattering data. In this work, the two spectrum unfolding approaches are compared in order to experimentally validate its robustness and to determine which is the optimal methodology for application on a clinical quality assurance routine. Both studied methods are based on EPID images generated when the incident photon beam impinges onto plastic blocks. The distribution of transmitted/scatter radiation produced by this object centered at the beam field size was measured. Measurements were performed using a 6 MeV photon beam p…

Measurements of neutron radiation and induced radioactivity for the new medical linear accelerator, the Varian TrueBeam

2016

Abstract Contemporary linear accelerators applied in radiotherapy generate X-ray and electron beams with energies up to 20 MeV. Such high-energy therapeutic beams induce undesirable photonuclear (γ,n) and electronuclear (e,e'n) reactions in which neutrons and radioisotopes are produced. The originated neutron can also induce reactions such as simple capture, (n,γ), reactions that produce radioisotopes. In this work measurements of the non-therapeutic neutrons and the induced gamma radiation were carried out in the vicinity of a new medical accelerator, namely the Varian TrueBeam. The TrueBeam is a new generation Varian medical linac making it possible to generate the X-ray beams with a dose…

Intense source of slow positrons from pulsed electron accelerators

1984

A pulsed LINAC is used for pair production in a tantalum target of 2.5 radiation lengths in an energy range from 80 to 260 MeV. Several well-annealed tungsten vanes are placed immediately behind the target and thermalize a small fraction of the fast positrons. The slow positrons are extracted from the target region and magnetically guided over a distance of 17 m to the detector at the end of an S-shaped solenoid. Two Nal detectors with well-known detection efficiency are used to register the 511 keV annihilationγ-rays. To reduce pile-up effects 50 mm of Pb were placed in front of the detectors. At an average electron current of 1 μA we could detect about 107 slow positrons per second. The p…

SU-E-T-218: Octavius 4D: Commissioning and Clinical Implementation of a New Device for VMAT Verifications

2013

Purpose: To commission a new device for pre‐treatment patient specific verification of VMAT plans, which is capable of reconstructing 3D dose with high resolution. Methods: Octavius 4D system (PTW) consists of an ion chamber array embedded in a cylindrical phantom which, assisted by an inclinometer, rotates synchronously with the gantry. For VMAT plans, it measures planar dose distributions as a function of gantry angle in order to compute the resulting 3D dose distribution. There are two options for the ion chamber array: Octavius 729 (general purpose) and Octavius 1000 SRS (small field size, high resolution). We have used three linacs: two Varian Clinac iX and one TrueBeam with MLC HD 120…