56333052
Benchmarking/Crosschecking DFS in the ILC Main Linac
In an effort to compare beam dynamics and create a ''benchmark'' for Dispersion Free Steering (DFS) a comparison was made between different ILC simulation programs while performing DFS. This study consisted of three parts. First, 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.
125706131
The Single Field Flip Cooling Channel for a Neutrino Factory
116611232
B Physics working group summary
Calculations of the B{sub c} spectrum of energy levels, transitions between levels, and weak decays of the ground state, as well as their production and observation at hadron colliders, are summarized. Also, recent experimental B Physics results from the CDF and D0 Tevatron experiments are reviewed and future prospects are discussed.
23121089
A comparison and benchmark of two electron cloud packages
We present results from precision simulations of the electron cloud (EC) problem in the Fermilab Main Injector using two distinct codes. These two codes are (i)POSINST, a F90 2D+ code, and (ii)VORPAL, a 2D/3D electrostatic and electromagnetic code used for self-consistent simulations of plasma and particle beam problems. A specific benchmark has been designed to demonstrate the strengths of both codes that are relevant to the EC problem in the Main Injector. As differences between results obtained from these two codes were bigger than the anticipated model uncertainties, a set of changes to the POSINST code were implemented. These changes are documented in this note. This new version of POSINST now gives EC densities that agree with those predicted by VORPAL, within {approx}20%, in the beam region. The root cause of remaining differences are most likely due to differences in the electrostatic Poisson solvers. From a software engineering perspective, these two codes are very different. We comment on the pros and cons of both approaches. The design(s) for a new EC package are briefly discussed.
122259234
A bottom collider vertex detector design, Monte-Carlo simulation and analysis package
A detailed simulation of the BCD vertex detector is underway. Specifications and global design issues are briefly reviewed. The BCD design based on double sided strip detector is described in more detail. The GEANT3-based Monte-Carlo program and the analysis package used to estimate detector performance are discussed in detail. The current status of the expected resolution and signal to noise ratio for the golden'' CP violating mode B{sub d} {yields} {pi}{sup +}{pi}{sup {minus}} is presented. These calculations have been done at FNAL energy ({radical}s = 2.0 TeV). Emphasis is placed on design issues, analysis techniques and related software rather than physics potentials. 20 refs., 46 figs.
59802398
Open inventor and virtual reality at Fermilab
We discuss our experiences with Open Inventor and with basic tools and techniques of Virtual Reality, including some preliminary results from an immersive system.
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.
118424090
The CLIC Programme: Towards a Staged e+e- Linear Collider Exploring the Terascale : CLIC Conceptual Design Report
This report describes the exploration of fundamental questions in particle physics at the energy frontier with a future TeV-scale e+e- linear collider based on the Compact Linear Collider (CLIC) two-beam acceleration technology. A high-luminosity high-energy e+e- collider allows for the exploration of Standard Model physics, such as precise measurements of the Higgs, top and gauge sectors, as well as for a multitude of searches for New Physics, either through direct discovery or indirectly, via high-precision observables. Given the current state of knowledge, following the observation of a 125 GeV Higgs-like particle at the LHC, and pending further LHC results at 8 TeV and 14 TeV, a linear e+e- collider built and operated in centre-of-mass energy stages from a few-hundred GeV up to a few TeV will be an ideal physics exploration tool, complementing the LHC. In this document, an overview of the physics potential of CLIC is given. Two example scenarios are presented for a CLIC accelerator built in three main stages of 500 GeV, 1.4 (1.5) TeV, and 3 TeV, together with operating schemes that will make full use of the machine capacity to explore the physics. The accelerator design, construction, and performance are presented, as well as the layout and performance of the experiments. The proposed staging example is accompanied by cost estimates of the accelerator and detectors and by estimates of operating parameters, such as power consumption. The resulting physics potential and measurement precisions are illustrated through detector simulations under realistic beam conditions.
121924363
Design and construction of a static magnetic refrigerator operatingbetween 1.8 K and 4.5 K
Abstract Following pioneer work a decade ago at CEA/CEN-Grenoble, France we have designed and constructed a static magnetic refrigerator with a capacity of about 20 W, operating on a quasi-Carnot cycle between 1.8 and 4.5 K. The active core, which contains 10.1 kg of single-crystal gadolinium-gallium garnet (GGG), is magnetized and demagnetized by a 3.5 T pulsed-field, low-loss superconducting magnet operating at 4.5 K. Thermal switching to the cold and warm sources is produced by alternatively flushing the core with liquid helium from the 1.8 and 4.5 K baths, by means of alumina-piston and -cylinder displacer pumps. Precise modelling of thermodynamic properties of GGG, as well as detailed analysis of the different sources of irreversibility, allow to estimate the available refrigeration power and optimize the operating cycle.
118096470
Helium cryogenic systems for the LEP2 and LHC projects at CERN
CERN is presently operating a large distributed 4.5 K helium cryo kW@4.5 K equivalent) for cooling the superconducting acceleration c km circumference LEP2 lepton collider. This also constitutes the fi cryogenic system (about 150 kW@4.5 K equivalent) for the future Collider (LHC), the high-field superconducting magnets of which superfluid helium. We briefly describe the main features of each sy progress of their development, construction and operation. INTRODUCTION Particle physics has volens nolens become a prime user of large cryogenics, through the generalized use of superconducting device guiding and focusing high-energy particles in recent accelerators an specific requirements, both qualitative and quantitative, set by a represented a strong driving force to stimulate technological develo push helium cryogenics out of the laboratory into industrial-scal operating with high reliability and high efficiency. At CERN, the E for Particle Physics, this evolution took place in the last d superconducting quadrupoles of the LEP high-luminosity insertions upgrade (LEP2) using superconducting acceleration cavities in larg Large Hadron Collider (LHC) project based on high-field superconduc superfluid helium cryogenics on an unprecedented scale (Figure 1).
108030818
Helium Cryogenics at the Lep Experimental Areas
LEP, the large electron-positron collider built at CERN, is now starting to operate. Its four experimental areas, installed in large caverns down to 150 m below ground, are equipped with two types of superconducting magnet, namely large detector solenoids and “low-beta” focusing quadrupoles, operated from common ancillary cryogenic systems. The large size, geographical dispersion, underground implantation and operating environment of LEP have set unusual constraints and dictated specific choices for the four helium cryogenic plants, distribution systems, magnet cryostats, and process operation, particularly as concerns operational flexibility, reliability, safety, remote control and automation. After describing the main design features of the cryogenic systems, we report on their installation, commissioning and first experience of operation.