A5075721370- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Magnetic confinement fusion research
- Superconducting Materials and Applications
- Nuclear Physics and Applications
- Laser-Plasma Interactions and Diagnostics
- Particle Detector Development and Performance
- Gyrotron and Vacuum Electronics Research
- Atomic and Subatomic Physics Research
- Quantum Chromodynamics and Particle Interactions
- Atomic and Molecular Physics
- Nuclear physics research studies
- Particle physics theoretical and experimental studies
- Distributed and Parallel Computing Systems
- High-Energy Particle Collisions Research
- Laser-Matter Interactions and Applications
- Computational Physics and Python Applications
- Scientific Computing and Data Management
- Quantum, superfluid, helium dynamics
- Plasma Diagnostics and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Laser Design and Applications
- Radiation Detection and Scintillator Technologies
- Electron and X-Ray Spectroscopy Techniques
- Research Data Management Practices
Oak Ridge National Laboratory
2014-2023
National Archives
2022
National Technical Information Service
2022
Office of Scientific and Technical Information
2022
University of Tennessee at Knoxville
2017
Fermi National Accelerator Laboratory
2012
United States Department of Energy
2006
Spallation Neutron Source
2006
Brookhaven College
2002
RIKEN BNL Research Center
2002
The particle accelerator simulation code PyORBIT is presented. structure, implementation, history, parallel and capabilities, future development of the are discussed. a new implementation extension algorithms original ORBIT that was developed for Spallation Neutron Source at Oak Ridge National Laboratory. has two level structure. upper uses Python programming language to control flow intensive calculations performed by lower implemented in C + language. capabilities based on MPI...
Thin carbon foils are used as strippers for charge exchange injection into high intensity proton rings. However, the stripping become radioactive and produce uncontrolled beam loss, which is one of main factors limiting power in Recently, we presented a scheme laser an ${\mathrm{H}}^{\ensuremath{-}}$ Spallation Neutron Source (SNS) ring. First, atoms converted to ${\mathrm{H}}^{0}$ by magnetic field, then excited from ground state upper levels laser, states protons field. In this paper...
We report on an experiment in which a negative hydrogen ion beam the Spallation Neutron Source (SNS) linear accelerator was replaced with of protons similar size and dynamics. Fractional loss superconducting part SNS measured to be at least $2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ for ${\mathrm{H}}^{\ensuremath{-}}$ beam, it order magnitude lower protons. Also has stronger dependence intensity than proton beams. These measurements verify recent theoretical explanation...
This Letter reports on the first demonstration of laser-assisted ${\mathrm{H}}^{\ensuremath{-}}$ charge exchange for microsecond duration beam pulses. Laser-assisted injection is a breakthrough technology that overcomes long-standing limitations associated with traditional method producing high intensity, time structured beams protons in accelerators via use carbon foils injection. The central theme this experiment novel techniques reduce laser power requirement to allow efficiency stripping...
XAL is an application programming framework used at the Spallation Neutron Source (SNS) project in Oak Ridge. It written Java, and provides users with a hierarchal view of accelerator. Features include database configuration accelerator structure, online envelope model that configurable from design or live machine values, for quickstart GUI development, scripting interface algorithm common toolkit shared resources. To date, about 25 applications have been written, many which are extensively...
A beam loss in the superconducting part of SNS linac has been observed during its commissioning and operation. Although does not prevent high power operation, it results an almost uniform irradiation components increased radiation levels tunnel. Multi-particle tracking could neither account for magnitude nor dependence on machine parameters. It was recently found that is consistent with intrabeam particle collisions resulting stripping H- ions. The paper describes experimental observations...
Laser-assisted stripping is a novel approach to ${\mathrm{H}}^{\ensuremath{-}}$ charge exchange that overcomes long-standing limitations associated with the traditional, foil-based method of producing high-intensity, time-structured beams protons. This paper reports on first successful demonstration laser technique for microsecond duration beams. The experiment represents factor 1000 increase in stripped pulse compared previous proof-of-principle demonstration. central theme implementation...
Utilizing noninvasive 2D scans with laser wires, we tomographically reconstructed the 4D transverse phase space distribution of a 1-GeV hydrogen ion (i.e., ${\mathrm{H}}^{\ensuremath{-}}$) beam during operation. The tomography is based on two new advances. First, extended formulation maximum entropy to take projections as input and derived theoretical results relevant our application. Second, introduced method ``perpendicular scans'' obtain cross-plane information from wire emittance...
This paper presents a scheme for three-step laser-based stripping of an ${\mathrm{H}}^{\ensuremath{-}}$ beam charge exchange injection into high-intensity proton ring. First, atoms are converted to ${\mathrm{H}}^{0}$ by Lorentz in strong magnetic field, then neutral hydrogen excited from the ground state upper levels laser, and remaining electron, now more weakly bound, is stripped field. The energy spread particles gives rise Doppler broadened absorption linewidth, which makes inefficient...
A new method of measuring the rms longitudinal Twiss parameters a beam in linear accelerators is presented. It based on using sum signals from position monitors sensitive to charge distribution bunch. The applicability demonstrated superconducting section Oak Ridge Spallation Neutron Source accelerator. results are compared direct measurement bunch profiles an interceptive shape monitor linac warm same Limitations discussed. fast and simple, can be used obtain initial for matching where...
A virtual accelerator (VA) concept and an implementation founded on TRACE3D PARMILA codes are presented. This is suitable for accelerators with a control system based EPICS consists of the portable channel access server (PCAS), client providing communication between simulation model PCAS, itself. The SNS linac experience in using these VAs discussed.
A new scheme with sequential resonant excitation for laser assisted charge exchange injection of ${\mathrm{H}}^{\ensuremath{-}}$ beams is proposed. In contrast the one step scheme, proposed requires significantly less power high efficiency stripping. It also provides greater flexibility in choice wavelength a given beam energy and extends range energies where stripping can be effectively applied. Calculations experimental plans 1.0 GeV 1.3 at Spallation Neutron Source are presented. Results...
Charge exchange injection is the standard mechanism used to accumulate short, intense pulses of proton beams from an ${\mathrm{H}}^{\ensuremath{-}}$ injector into a synchrotron. Historically, this process has relied on foils remove two electrons ${\mathrm{H}}^{\ensuremath{-}}$, technique that been successfully employed for beam powers up 1.4 MW. However, such are known sublimate beyond threshold power density, requiring development another stripping technology does not have same limitation....
The Spallation Neutron Source accelerator systems will deliver a 1.0 GeV, 1.4 MW proton beam to liquid mercury target for neutron scattering research. complex consists of an H-injector, capable producing one-ms-long pulses at 60 Hz repetition rate with 38 mA peak current, 1 GeV linear accelerator, accumulator ring and associated transport lines. 2.5 MeV from the Front End is accelerated 86 in Drift Tube Linac, then 185 Coupled-Cavity Linac finally Superconducting Linac. With completion...
The longitudinal acceptance of the Spallation Neutron Source superconducting linac is computed with a model. A beam current monitor and loss monitors are utilized in new measurement technique, measured results show close agreement Based on simulations measurements acceptance, we developed novel method to measure bunch shape, energy profile, emittance at entrance linac. experimental reveal that large halo exists injected linac, rms approximately twice nominal design. simple applicable other linacs.
Thin carbon foils are used as strippers for charge exchange injection into high intensity proton rings. However, the stripping become radioactive and produce uncontrolled beam loss, which is one of main factors limiting power in Recently, we presented a scheme laser an H <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-</sup> Spallation Neutron Source ring. First, atoms converted to xmlns:xlink="http://www.w3.org/1999/xlink">0</sup> by magnetic...
The use of stripping foils for charge exchange injection can cause a number operational problems in high intensity hadron accelerators. A recently proposed three-step method laser-assisted is capable overcoming these problems. This paper presents advances the physical model ${\mathrm{H}}^{\ensuremath{-}}$ beams and covers wide field atomic physics. allows calculation evolution an ${\mathrm{H}}^{0}$ beam taking into account spontaneous emission, ionization, external electromagnetic fields....