W. Fischer
A5085521261- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Magnetic confinement fusion research
- Particle Detector Development and Performance
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- European history and politics
- Gyrotron and Vacuum Electronics Research
- X-ray Spectroscopy and Fluorescence Analysis
- Electron and X-Ray Spectroscopy Techniques
- European Political History Analysis
- Laser-Plasma Interactions and Diagnostics
- Advanced Data Storage Technologies
- Photocathodes and Microchannel Plates
- Quantum Chromodynamics and Particle Interactions
- Atomic and Molecular Physics
- Flexible and Reconfigurable Manufacturing Systems
- Advancements in Photolithography Techniques
- Atomic and Subatomic Physics Research
- Plasma Diagnostics and Applications
- German Social Sciences and History
- Advanced X-ray Imaging Techniques
- Reformation and Early Modern Christianity
- Ion-surface interactions and analysis
Brookhaven National Laboratory
2013-2023
Fermi National Accelerator Laboratory
2009-2017
Brookhaven College
2013-2014
RIKEN BNL Research Center
1999-2010
National Library of Luxembourg
2007
Institute on Taxation and Economic Policy
2006
Klinikum Sindelfingen-Böblingen
1997-2004
GSI Helmholtz Centre for Heavy Ion Research
2004
Lawrence Berkeley National Laboratory
2002
European Organization for Nuclear Research
1995-2002
A new experiment is described to detect a permanent electric dipole moment of the proton with sensitivity $10^{-29}e\cdot$cm by using polarized "magic" momentum $0.7$~GeV/c protons in an all-electric storage ring. Systematic errors relevant are discussed and techniques address them presented. The measurement sensitive physics beyond Standard Model at scale 3000~TeV.
Abstract Die Frage, ob und wie der technische Fortschritt gesteuert gebremst werden könne, wird heute von vielen Skeptikern des Fortschrittsglaubens gestellt. Hier zunächst die Frage ausführlich untersucht, weshalb gerade Europa seit Ausgang Mittelalters an Spitze Entwicklung Technik Naturwissenschaft getreten ist, obwohl in anderen Erdteilen schon früher viele Voraussetzungen dafür bestanden. „offene Gesellschaft”︁ Mitteleuropas erweist sich als ausschlaggebende Vorbedingung. Seit Beginn...
Static electric dipole moments of nondegenerate systems probe mass scales for physics beyond the Standard Model well those reached directly at high energy colliders. Discrimination between different models, however, requires complementary searches in atomic-molecular-and-optical, nuclear and particle physics. In this report, we discuss current status prospects near future a compelling suite such experiments, along with developments needed encompassing theoretical framework.
Since 2001, the Relativistic Heavy Ion Collider has experienced electron cloud effects, some of which have limited beam intensity. These include dynamic pressure rises (including instabilities), tune shifts, a reduction instability threshold for bunches crossing transition energy, and possibly incoherent emittance growth. We summarize main observations in operation dedicated experiments as well countermeasures including baking, nonevaporable getter coated warm pipes, solenoids, bunch...
Cooling of beams gold ions using electron bunches accelerated with radio-frequency systems was recently experimentally demonstrated in the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. Such an approach is new and opens possibility this technique higher energies than possible electrostatic acceleration beams. The challenges include generation suitable for cooling, delivery required quality to cooling sections without degradation beam angular divergence energy spread,...
Recently, resonance driving terms were successfully measured in the CERN SPS and BNL RHIC from Fourier spectrum of beam position monitor (BPM) data. Based on these measurements a new analysis has been derived to extract truly local observables BPM These are called since they share some similarities with global terms. In this paper we derive analytically present experimental sextupolar RHIC. Nondestructive using ac dipoles also presented.
We report the first observations of beam losses due to bound-free pair production at interaction point a heavy-ion collider. This process is expected be major luminosity limit for CERN Large Hadron Collider when it operates with (208)Pb(82+) ions because localized energy deposition by lost may quench superconducting magnet coils. Measurements were performed BNL Relativistic Heavy Ion (RHIC) during operation 100 GeV/nucleon (63)Cu(29+) ions. At RHIC, rate, and magnetic field are low enough so...
Head-on beam-beam compensation has been implemented in the Relativistic Heavy Ion Collider order to increase luminosity delivered experiments. We discuss principle of combining a lattice for resonance driving term and an electron lens tune spread compensation. describe technology its operational use. To date, scheme approximately doubled peak average luminosities.
To compensate the beam-beam tune spread and resonance driving terms in polarized proton operation Relativistic Heavy Ion Collider (RHIC), we will introduce a low energy DC electron beam into each ring to collide head-on with opposing beam. The device provide is called an lens. In this article, using 6D weak-strong interaction simulation model, investigate effects of compensation lenses on dynamics for RHIC 250 GeV operation. Frequency maps, dynamic apertures, loss rates are calculated study....
The Brookhaven Relativistic Heavy Ion Collider (RHIC) has been providing collisions of polarized protons at a beam energy 100 GeV since 2001. Equipped with two full Siberian snakes in each ring, polarization is preserved during acceleration from injection to GeV. However, the intrinsic spin resonances beyond are about factor 2 stronger than those below making it important examine impact these strong on survival and tolerance for vertical orbit distortions. Polarized were first accelerated...
The dynamic aperture experiment at the CERN Super Proton Synchrotron (SPS) was aimed finding relevant effects that limit single-particle stability in hadron storage rings. These were studied SPS and compared with long-term particle tracking to determine what extent computer simulations can predict under well-known conditions. Such investigations are very important for future colliders such as Large Hadron Collider design of these machines relies heavily on simulations. Besides this practical...
Intense ion beams in the Brookhaven Relativistic Ion Collider lead to a rise vacuum pressure. Electron clouds can contribute such process. To measure electron cloud densities coherent tune shift along bunch train was observed with different spacings and intensities. From measured shifts, are computed compared obtained simulations.
We have studied the time evolution of heavy-ion luminosity and bunch intensities in Relativistic Heavy Ion Collider (RHIC) at BNL, Large Hadron (LHC) CERN. First, we present measurements from a large number RHIC stores (from run-7), colliding $100\text{ }\text{ }\mathrm{GeV}/\mathrm{nucleon}$ $^{197}\mathrm{Au}^{79+}$ beams without stochastic cooling. These are compared with two different calculation methods. The first is simulation based on multiparticle tracking taking into account...
A hollow electron beam has been proposed as an active control tool to remove the halo from high-energy, high-current hadron or ion machines (such High-Luminosity Large Hadron Collider). To study removal rate and assess effect on core, one of two lenses in Relativistic Heavy Ion Collider was changed a Gaussian profile profile. We describe design verification parameters well methods minimize distortions, which can result emittance increase. The alignment with by using backscattered detector...
Two electron lenses ($e$-lenses) have been in operation during the 2015 RHIC physics run as part of a head-on beam-beam compensation scheme. While lattice was chosen to reduce beam-beam-induced resonance-driving terms, reduced tune spread. This has demonstrated for first time. The scheme allows higher parameters and therefore intensities luminosity. In this paper, we detail design considerations verification beam $e$-lenses. Longitudinal transverse alignments with ion beams transfer function...
The Low Energy RHIC electron Cooling (LEReC) project at Brookhaven National Laboratory recently demonstrated for the first time cooling of hadron bunches with radio-frequency (rf) accelerated bunches. LEReC uses a high-voltage photoemission gun stringent requirements beam current, quality, and stability. has photocathode high-power fiber laser, novel cathode production, transport, exchange system. It been that can continually produce high-current quality suitable cooling. We describe...
A high-current high-brightness electron accelerator for low-energy RHIC cooling (LEReC) was successfully commissioned at Brookhaven National Laboratory. The LEReC includes a dc photoemission gun, laser system, photocathode delivery magnets, beam diagnostics, superconducting rf booster cavity, and set of normal conducting cavities to provide enough flexibility tune the in longitudinal phase space. Cooling with nonmagnetized accelerated beams requires corrections obtain small momentum spread...
Trapping by resonances or scattering off induced space charge (SC) electron cloud (EC) in conjunction with synchrotron motion can explain observations of slow beam loss and emittance growth, which are often accompanied changes the longitudinal profile. In this paper we review recent progress understanding modeling underlying mechanisms, highlight differences similarities between cloud, discuss simulation results light experimental observations, e.g., at GSI, CERN, BNL. particular, address...
The Low Energy Relativistic Heavy Ion Collider (RHIC) Electron Cooler (LEReC) is the world's first electron cooler using rf-accelerated bunches. Recently, cooling of gold ion beams in RHIC by 1.6 and 2.0 MeV electrons was successfully achieved. Along with velocity spread alignment beam, space-charge force between ions also plays an important role process. In order to investigate dynamics bunched provide guidance for LEReC operation, a simulation code developed, which includes nonmagnetized...
We describe a proposal to search for an intrinsic electric dipole moment (EDM) of the proton with sensitivity \targetsens, based on vertical rotation polarization stored beam. The New Physics reach is order $10^~3$TeV mass scale. Observation EDM provides best probe CP-violation in Higgs sector, at level that may be inaccessible electron-EDM experiments. improvement $\theta_{QCD}$, parameter crucial axion and dark matter physics, about three orders magnitude.