122472626
Recent results from Fermilab E687 on charm spectroscopy
Recent analyses of charm spectroscopy from Fermilab fixed target experiment 687 [1] are summarized. Emphasis is placed on the phenomenology of Cabibbo suppression in the meson sector. Such transitions have been observed in the semileptonic modes and hadronic modes. While the former transitions give us an opportunity to observe the weak current and the CKM matrix, a systematic comparison of the latter transitions allow us to study strong interaction effects, and possibly, light quark spectroscopy.
33125511
Beam-Beam Effects in the Tevatron Run II
Electromagnetic long-range and head-on interactions of high intensity proton and antiproton beams are significant sources of beam loss and lifetime limitations in the Tevatron Collider Run II (2001-present). We present observations of the beam-beam phenomena in the Tevatron and results of relevant beam studies. We analyze the data and various methods employed in high energy physics (HEP) operation, predict the performance for planned luminosity upgrades and discuss ways to improve it.
16599712
Comparison of tracking codes for the International Linear Collider
In an effort to compare beam dynamics and create a "benchmark" for Dispersion Free Steering (DFS) a comparison was made between different International Linear Collider (ILC) simulation programs while performing DFS. This study consisted of three parts. Firstly, a simple betatron oscillation was tracked through each code. Secondly, a set of component misalignments and corrector settings generated from one program was read into the others to confirm similar emittance dilution. Thirdly, given the same set of component misalignments, DFS was performed independently in each program and the resulting emittance dilution was compared. Performance was found to agree exceptionally well in all three studies.
116622236
Beam simulation tools for GEANT4 (and neutrino source applications)
Geant4 is a tool kit developed by a collaboration of physicists and computer professionals in the High Energy Physics field for simulation of the passage of particles through matter. The motivation for the development of the Beam Tools is to extend the Geant4 applications to accelerator physics. Although there are many computer programs for beam physics simulations, Geant4 is ideal to model a beam going through material or a system with a beam line integrated to a complex detector. There are many examples in the current international High Energy Physics programs, such as studies related to a future Neutrino Factory, a Linear Collider, and a very Large Hadron Collider.
62352767
ASPECTS OF SCIENTIFIC VISUALIZATION FOR HEP ANALYSIS AT FERMILAB
1161525
Recent studies of dispersion matched steering for the ILC bunch compressor and main linac
The dispersion matched steering (DMS) method is studied in detail in the context of a curved main linac. In the absence of cavity tilts (rotations in the YZ plane), DMS provides a unique and stable solution with negligible emittance growth. If cavity tilts are about 300 murad, the algorithm is not very robust. The emittance growth through the entire linac for positrons is about 5 nm, if the system is strictly static and statistical averaging can be used to improve beam position measurements. This growth is mostly eliminated if the dispersion and its derivative at injection can be adjusted. If anticipated ground motion, beam and klystron jitter, beam position measurement resolution are introduced (i.e. dynamical case), the emittance preservation goal is currently not achieved by DMS alone. Mitigation strategies are outlined.
124923269
400-Meters of Flexible Cryogenic Helium Transfer Lines.
117713839
CONCEPTUAL STUDY OF THE SUPERFLUID HELIUM CRYOGENIC SYSTEM FOR THE CERN LARGE HADRON COLLIDER (LHC)
Studies are presently being made on the possibility of installing a Large Hadron Collider (LHC) in the existing underground tunnel of the LEP accelerator at CERN. The main element of the LHC would be a ring of 10 T superconducting magnets, distributed over the 26.7 km circumference of the machine. One of the current ideas is to use Nb-Ti magnets operated in superfluid helium. This paper presents possible solutions for a long distributed superfluid helium system within the constraints of an accelerator environment.
118953198
Design and construction of a superfluid helium cryostat for a ten-meter long high-field superconducting dipole magnet
55539240
Conceptual design of the cryogenic system for the Large Hadron Collider (LHC)
The high-field superconducting magnets to be installed on the 26.7 km circumference of the Large Hadron Collider at CERN will operate below 1.9 K in pressurised superfluid helium, thus requiring the development and implementation of a cryogenic system unprecedented in size, refrigeration capacity and complexity. After recalling the basic features of LHC cryogenics, which allow to make full use of the peculiar properties of superfluid helium as a technical coolant for accelerator devices, we present recent updates in performance requirements and changes in architecture of the system, discuss their technical impact, and review the status of development of the key technologies involved.
17967899
Summary of Session 2 : Beam Dynamics and Intensity Challenges
We summarize the Session 2 of the HHH-2004 workshop, which was devoted to beam dynamics and intensity challenges. The topics discussed included the extrapolation of collimation system, machine protection, beam dump, and rf systems to various LHC upgrade scenarios, spacecharge studies for the GSI complex, electron-cloud effects at RHIC and SNS, and a review of vacuum physics, which addressed, in particular, the possible interplay of ions and electron-cloud effests.