C. Adolphsen
A5076143653- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Gyrotron and Vacuum Electronics Research
- Superconducting Materials and Applications
- Particle physics theoretical and experimental studies
- Particle Detector Development and Performance
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Radiation Detection and Scintillator Technologies
- Magnetic confinement fusion research
- Dark Matter and Cosmic Phenomena
- Photocathodes and Microchannel Plates
- Advanced X-ray Imaging Techniques
- Microwave Engineering and Waveguides
- Muon and positron interactions and applications
- Nuclear Physics and Applications
- Distributed and Parallel Computing Systems
- Neutrino Physics Research
- Laser-Plasma Interactions and Diagnostics
- Plasma Diagnostics and Applications
- Electromagnetic Compatibility and Measurements
- Electrostatic Discharge in Electronics
- Radiation Effects in Electronics
- Photonic and Optical Devices
- Integrated Circuits and Semiconductor Failure Analysis
SLAC National Accelerator Laboratory
2013-2023
Stanford University
1995-2023
Linac Coherent Light Source
2002-2018
Menlo School
2007-2018
Fermi Research Alliance
2015
Chinese Academy of Sciences
2012
Institute of High Energy Physics
2012
Stanford Synchrotron Radiation Lightsource
1995-2008
Lawrence Berkeley National Laboratory
1988-2003
University of California, Santa Cruz
1986-2003
The physics programme and the design are described of a new collider for particle nuclear physics, Large Hadron Electron Collider (LHeC), in which newly built electron beam 60 GeV, up to possibly 140 energy collides with intense hadron beams LHC. Compared HERA, kinematic range covered is extended by factor twenty negative four-momentum squared, $Q^2$, inverse Bjorken $x$, while luminosity $10^{33}$ cm$^{-2}$s$^{-1}$ LHeC projected exceed integrated HERA two orders magnitude. devoted an...
We present the results of a study muon pairs with invariant masses greater than 4.05 GeV/${c}^{2}$ produced in high-energy pion-nucleon interactions. The production cross section together inferred pion and nucleon structure functions are reported compared other experiments QCD predictions. transverse-momentum distributions also presented. Finally, full angular distribution cos\ensuremath{\theta} \ensuremath{\varphi} is given as function mass, Feynman x, transverse momentum. Longitudinal...
We have measured the mass of Z boson to be 91.14±0.12 GeV/c2, and its width 2.42+0.45−0.35 GeV. If we constrain visible standard-model value, find partial invisible decay modes 0.46±0.10 GeV, corresponding 2.8±0.6 neutrino species, with a 95%-confidence-level upper limit 3.9.Received 12 October 1989DOI:https://doi.org/10.1103/PhysRevLett.63.2173©1989 American Physical Society
We have measured the mass of Z boson to be 91.11±0.23 GeV/c2, and its width 1.61+0.60−0.43 GeV. If we constrain visible standard-model value, find partial invisible decay modes 0.62±0.23 GeV, corresponding 3.8±1.4 neutrino species.Received 24 July 1989DOI:https://doi.org/10.1103/PhysRevLett.63.724©1989 American Physical Society
Multihadronic e+e− annihilation events at a center-of-mass energy of 29 GeV have been studied with both the original (PEP 5) Mark II and upgraded detectors. Detector-corrected distributions from global shape analyses such as aplanarity, Q2-Q1, sphericity, thrust, minor value, oblateness, jet masses, inclusive charged-particle including x, rapidity, p⊥, particle flow are presented. These compared predictions various multihadron event models which use leading-logarithmic shower evolution or...
We measured the differential jet-multiplicity distribution in ${e}^{+}$${e}^{\mathrm{\ensuremath{-}}}$ annihilation with Mark II detector. This is compared second-order QCD prediction and ${\ensuremath{\alpha}}_{s}$ determined to be 0.123\ifmmode\pm\else\textpm\fi{}0.009\ifmmode\pm\else\textpm\fi{}0.005 at \ensuremath{\surd}s\ensuremath{\approxeq}${\mathit{M}}_{\mathit{Z}}$ (at SLAC Linear Collider) 0.149\ifmmode\pm\else\textpm\fi{}0.002\ifmmode\pm\else\textpm\fi{}0.007...
Acceleration gradient is a critical parameter for the design of future TeV-scale linear colliders. The major obstacle to higher in room-temperature accelerators rf breakdown, which still very mysterious phenomenon that depends on geometry and material accelerator as well input power operating frequency. Pulsed heating has been associated with breakdown many years; however, there have no experiments clearly separate field effects rate. Recently, such performed at SLAC both standing-wave...
We present the first measurement of left-right cross section asymmetry (${\mathit{A}}_{\mathit{L}\mathit{R}}$) for Z boson production by ${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{\ensuremath{-}}}$ collisions. The was performed at a center-of-mass energy 91.55 GeV with SLD detector SLAC Linear Collider which utilized longitudinally polarized electron beam. average beam polarization (22.4\ifmmode\pm\else\textpm\fi{}0.6)%. Using sample 10 224 decays, we measure...
The distributions of quarks in the pion and nucleon are extracted from measurements reaction ${\ensuremath{\pi}}^{\ensuremath{-}}N\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}X$ at 253 GeV/c a naive Drell-Yan analysis, as well QCD-corrected analyses leading-log next-to-leading-log order. As ${x}_{\ensuremath{\pi}}\ensuremath{\rightarrow}1$ structure function shows term that varies $\frac{1}{{m}_{\ensuremath{\mu}\ensuremath{\mu}}^{4}}$, which we interpret...
For the Linac Coherent Light Source II (LCLS-II) project at SLAC, a 1.3 GHz superconducting rf (SRF) linac is being constructed that will generate 4 GeV electron bunches high repetition rate to drive x-ray free lasers. The LCLS-II source, which comprises first three meters of injector, includes two normal-conducting, continuous-wave cavities: one-cell, 185.7 MHz gun and two-cell, buncher. It also load-lock system allows photocathodes be changed under vacuum. components in this beam-line...
We have measured inclusive distributions for charged particles in hadronic decays of the Z boson. The variables chosen study were charged-particle multiplicity, scaled momentum, and momenta transverse to sphericity axes. been corrected detector effects are compared with data from e+e− annihilation at lower energies predictions several QCD-based models. reasonable agreement expectations.Received 18 December 1989DOI:https://doi.org/10.1103/PhysRevLett.64.1334©1990 American Physical Society
The designs for a next-generation linear collider based on normal-conducting rf structures require operation at gradients much higher than those in existing linacs. For the NLC/JLC 11.4-GHz structures, design unloaded gradient is 65 MV/m, which about four times that of 2.9-GHz SLAC Linac. CLIC proposal using 30-GHz requires an even gradient, 170 MV/m. Both and groups are aggressively pursuing programs to develop operate reliably these also have acceptable efficiencies transverse wakefields....
Building more compact accelerators to deliver high brightness electron beams for the generation of flux, highly coherent radiation is a priority photon science community. A relatively straightforward reduction in footprint can be achieved by using high-gradient X-band (11.4 GHz) rf technology. To this end, an injector consisting 5.5 cell gun and 1-m long linac has been commissioned at SLAC. It delivers 85 MeV beam with peak somewhat better than that S-band photoinjectors, such as one...
An eight-cavity, 1.3 GHz, SLAC linac coherent light source II High Energy cryomodule was assembled and tested at Fermilab to verify performance before the start of production. Its cavities were processed with a novel nitrogen doping treatment improve gradient performance. The modified protocol process sporadic quenches, which observed in Linac Coherent Light Source production cryomodules are attributed multipacting. Dedicated vertical test experiments support attribution verification...
During the past five years, there has been an concerted program at SLAC and KEK to develop accelerator structures that meet high gradient (65 MV/m) performance requirements for Next Linear Collider (NLC) Global (GLC) initiatives. The design resulted is a 60-cm-long, traveling-wave structure with low group velocity 150 degree per cell phase advance. It average iris size produces acceptable short-range wakefield, dipole mode damping detuning adequately suppresses long-range wakefield. More...
As a by-product to the study of muon pairs produced by 255-Ge V/c pions, data from Fermilab yield upper limits on decay ${D}^{0}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ and ${D}^{0}\ensuremath{-}{\overline{D}}^{0}$ mixing. An unrestricted sample 122 630 unlike-sign allows 90%-C.L. (confidence level) limit 1.1\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}5}$ be placed branching ratio charm-changing neutral-current...
The production of ${\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ pairs with large longitudinal momentum has been studied in ${\ensuremath{\pi}}^{\ensuremath{-}}N$ collisions. data confirm an earlier result that most the pair takes place via longitudinally polarized virtual photons as ${x}_{\mathrm{F}}\ensuremath{\rightarrow}1$. transverse-momentum distribution muon shows a marked narrowing same limit. valence quarks pion is extracted, and indicates nonzero probability having...
The spin alignment of 2.2\ifmmode\times\else\texttimes\fi{}${10}^{6}$ J/\ensuremath{\psi} particles produced in 252-GeV \ensuremath{\pi}N interactions has been measured via their decay to ${\ensuremath{\mu}}^{+}$${\ensuremath{\mu}}^{\mathrm{\ensuremath{-}}}$ an experiment at Fermilab. Whereas J/\ensuremath{\psi}'s are unpolarized over most the kinematic range, they found become longitudinally polarized as ${x}_{F}$\ensuremath{\rightarrow}1.