Search results for "Filter"
showing 10 items of 1019 documents
Determination of the partial electron capture- and spontaneous-fission half-lives of254No
1988
The isotope254No was produced in the fusion reaction48Ca +208Pb. Using the velocity filter SHIP and radiochemical techniques it was found that the nuclide254No with a half-life of 55 s decays byα, EC, and spontaneous-fission. Deduced partial half-lives are (61±2) s forα-decay, (550−160+370) s for EC and [2.2−1.0+2.0]×104 s for spontaneous fission.
The Deterministic Annealing Filter: A new clustering method for gamma-ray tracking algorithms
2010
A new method of clustering for forward-tracking algorithms has been developed to reconstruct the tracks of gamma-rays in high-resolution detector systems such as AGATA (Advanced GAmma Tracking Array). This technique, called Deterministic Annealing Filter (DAF), comes from statistical physics and is used in high-energy physics. After a description of the DAF method and of the forward-tracking algorithm, the performance of this clustering method is discussed in terms of photopeak efficiency and peak-to-total ratio obtained with GEANT4 simulations for the AGATA geometry. A comparison with the standard so-called "cone clustering method" shows similar performances with a better photopeak efficie…
NONCOMMUTATIVE GEOMETRY AND GRADED ALGEBRAS IN ELECTROWEAK INTERACTIONS
1992
The Standard Model of Electroweak Interactions can be described by a generalized Yang-Mills field incorporating both the usual gauge bosons and the Higgs fields. The graded derivative by means of which the Yang-Mills field strength is constructed involves both a differential acting on space-time and a differential acting on an associative graded algebra of matrices. The square of the curvature for the corresponding covariant derivative yields the bosonic Lagrangian of the Standard Model. We show how to recover the whole fermionic part of the Standard Model in this framework. Quarks and leptons fit naturally into the smallest typical and nontypical irreducible representations of the graded …
Kalman filter tracking and vertexing in a silicon detector for neutrino physics
2002
Abstract This article describes the application of Kalman filter techniques for the tracking and vertexing of particles inside the NOMAD-STAR detector, a silicon vertex detector installed in NOMAD, one of the neutrino oscillation experiments at the CERN-SPS. The use of the Kalman filter simplifies computationally the tracking and vertex procedure for NOMAD-STAR. The alignment of NOMAD-STAR is shown as an example of the application of the Kalman filter for tracking purposes. The accuracy of the method is such that one obtains alignment residuals between 9 and 12 μm . Furthermore, a preliminary measure of the impact parameter (with an RMS ∼36 μm ) illustrates the vertexing capabilities of thi…
A low-noise and fast pre-amplifier and readout system for SiPMs
2015
Abstract To operate silicon photomultipliers (SiPMs) in a demanding environment with large temperature gradients, different amplifier concepts were characterized by analyzing SiPM pulse-shapes and charge distributions. A fully differential 4-wire SiPM pre-amplifier with separated tracks for the bias voltage and with good common-mode noise suppression was developed and successfully tested. To achieve highest single-pixel resolutions an online after-pulse and pile-up suppression was realized with fast readout electronics based on digital filters.
“RecPack” a reconstruction toolkit
2004
We present a C++ toolkit to do tracking and vertex reconstruction. The toolkit incorporates common fitting methods, as the Kalman Filter, a framework to define a detector setup, a general navigation and a simple simulation. Furthermore, the toolkit provides a collection of interfaces which facilitates the addition of new fitting methods, trajectory models, geometrical objects, pattern recognition logic, etc. Although the toolkit was originally developed to be used in High Energy Physics, it could be applied to other fields.
Wien filter for cooled low-energy radioactive ion beams
2002
A Wien filter for cooled radioactive ion beams has been designed at Ion Guide Isotope Separator On Line technique (IGISOL). The purpose of such device is to eliminate doubly charged ions from the mass separated singly charged ions, based on q=+2→q=+1 charge exchange process in an ion cooler. The performance of the Wien filter has been tested off-line with a discharge ion source as well as on-line with a radioactive beam. The electron capture process of cooled q=+2 ions has been investigated in a radiofrequency quadrupole ion cooler with varying partial pressures of nitrogen. Also, the superasymmetric fission production yields of 68<A<78 nuclei have been deduced.
Operation of the MAMI accelerator with a Wien filter based spin rotation system
2006
A compact spin rotation system based on a Wien filter has been installed at the Mainz microtron accelerator (MAMI). Under operation with varying spin rotation angles a significant change of focal length together with a shift of the central beam trajectory is expected. We demonstrate that these effects can be kept under control. As a consequence operation with spin rotation angles between 0° and ±90° has been achieved without compromising the beam quality and operational stability of MAMI.
The optical/UV filters for the EPIC experiment
1998
EPIC, the European Photon Imaging Cameras is an experiment based on cooled CCDs on board the ESA X-ray Multi Mirrors satellite due to be launched in 1999. Since CCD's are sensitive to radiation other than X-rays, namely Optical and UV light, filters are necessary to prevent this radiation from reaching the detector sensitive area. Three types of filters were developed, to be used alternatively depending on target source. Here we report on the medium and thin filters developed by MOXTEK Inc. in Orem, Utah, while the thick ones, developed at the Max-Planck-Institut fur Extraterrestrische Physik (MPE, Germany) have been described elsewhere. The two filters, described here, have a 1600 /spl Ari…
The3He neutron spin filter at ILL
1997
Abstract Neutron Spin-Filters (NSF) using gaseous polarized 3He have long been recognized as having enormous potential value in many polarized neutron scattering applications and, accordingly, ILL started a development program some years ago. This report gives an account of the present status of the project. Let us first briefly recall the reasons why the 3He-NSF is desirable as a generic polarization tool: Being a pure transmission device, NSF naturally decouples the neutron spin selection from other optical functions. Designing polarized instruments will be simplified having no geometrical constraints due to Bragg optics or beam deviation in the polarizer. Angular acceptance and energy ba…