Office Of High Energy Physics Research Articles

Design of the cryostat for High Field Vertical Magnet Testing Facility at Fermilab

High Field Vertical Magnet Test Facility (HFVMTF) is a joint project between the Office of High Energy Physics (HEP) and the Office of Fusion Energy Sciences (FES). Its construction is currently under way at Fermi National Accelerator Laboratory (Fermilab). As a part of the project a new double bath superfluid helium cryostat has been designed. The cryostat can accommodate magnets with up to 20 tonne weight and 1.3 m diameter. This paper discusses challenges and solutions for cryostat, lambda plate and heat exchanger design, and presents results of performance analysis.

Magnetic and Mechanical Analysis of a Large Aperture 15 T Cable Test Facility Dipole Magnet

The US Department of Energy (DOE) Office of Science (SC), is funding a large bore “Cable Test Facility Magnet” for testing advanced cables and inserts in high transverse field. This is a joint effort between the Office of High Energy Physics (HEP) and the Office of Fusion Energy Sciences (FES). The background field magnet for this facility is being developed at Lawrence Berkeley National Laboratory (LBNL) while the cryostat and test facility will be located and operated by Fermi National Accelerator Laboratory (FNAL). The Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3 </sub> Sn dipole magnet, which will provide the transverse background field, is designed to generate a field of 15 T in a 100 × 150 mm bore at 1.9 K. The conceptual design of a block-type dipole with flared ends and a structure based on key-and-bladder technology will be introduced. The results of the magnetic and mechanical analysis will be presented.

RHIC’s future looks bright

Bertram Schwarzschild’s Issues and Events piece on the National Research Council’s report Revealing the Hidden Nature of Space and Time (Physics Today, June 2006, page 26) states, “Fermilab’s Tevatron is unlikely to outlive the decade. Neither is the PEP-II asymmetric electron–positron collider at SLAC nor the Relativistic Heavy Ion Collider at Brookhaven National Laboratory.”Placing RHIC in this context is odd since the NRC report nowhere mentions it. RHIC is funded by the Office of Nuclear Physics in the US Department of Energy’s Office of Science, not by the Office of High Energy Physics, for which the NRC committee was charged with recommending priorities for the next 15 years.More important, the notion that RHIC is “unlikely to outlive the decade” is misbegotten. The scientific impact of RHIC has been outstanding; its discovery of the “perfect liquid” of quarks and gluons was named the number-one physics story of 2005 by the American Institute of Physics publication Physics News Update and garnered media coverage around the world.Brookhaven National Laboratory is currently working with the Office of Nuclear Physics to implement for RHIC a strategy for the period 2006–11 aimed at a 10-fold luminosity upgrade and detector upgrades. This strategy will place RHIC at the forefront of research in high-temperature quantum chromodynamics (QCD) for at least another 10 years. Furthermore, RHIC is the first and only hadron collider with the ability to accelerate, store, and collide polarized protons at energies up to 500 GeV in the center-of-mass frame. It therefore provides unique opportunities to study the spin content of the nucleon—a program that also will extend into the next decade.Beyond that is the prospect of using RHIC as the basis for a polarized electron-ion collider, an option for an international next-generation facility for the study of QCD. That option will be discussed by the Nuclear Science Advisory Committee in 2007 as it develops its long-range plan for the field. If longevity is based on compelling science to be done, such a QCD facility—with ion–ion, proton–ion, polarized proton–proton, polarized electron–proton, and electron–ion collisions at high energy—would likely outlive the next decade.© 2006 American Institute of Physics.

Towards the petascale in electromagnetic modeling of plasma-based accelerators for high-energy physics

Plasma-based lepton acceleration concepts are a key element of the long-term R&D portfolio for the U.S. Office of High Energy Physics. There are many such concepts, but we consider only the laser (LWFA) and plasma (PWFA) wakefield accelerators. We present a summary of electromagnetic particle-in-cell (PIC) simulations for recent LWFA and PWFA experiments. These simulations, including both time explicit algorithms and reduced models, have effectively used terascale computing resources to support and guide experiments in this rapidly developing field. We briefly discuss the challenges and opportunities posed by the near-term availability of petascale computing hardware.

Impact of SciDAC on accelerator projects across the office of science through electromagnetic modeling

Electromagnetic Modelling led by SLAC is a principal component of the "Advanced Computing for 21st Century Accelerator Science and Technology" SciDAC project funded through the Office of High Energy Physics. This large team effort comprises three other national laboratories (LBNL, LLNL, SNL) and six universities (CMU, Columbia, RPI, Stanford, UC Davis and U of Wisconsin) with the goal to develop a set of parallel electromagnetic codes based on unstructured grids to target challenging problems in accelerators, and solve them to unprecedented realism and accuracy. Essential to the code development are the collaborations with the ISICs/SAPP in eigensolvers, meshing, adaptive refinement, shape optimization and visualization (see "Achievements in ISICs/SAPP Collaborations for Electromagnetic Modelling of Accelerators"). Supported by these advances in computational science, we have successfully performed the large-scale simulations that have impacted important accelerator projects across the Office of Science (SC) including the Positron Electron Project (PEP) -II, Next Linear Collider (NLC) and the International Linear Collider (ILC) in High Energy Physics (HEP), the Rare Isotope Accelerator (RIA) in Nuclear Physics (NP) and the Linac Coherent Light Source (LCLS) in Basic Energy Science (BES).