The application of the SXF lattice description and the UAL software environment to the analysis of the LHC

A software environment for accelerator modeling has been developed which includes the UAL (Unified Accelerator Library), a collection of accelerator physics libraries with a Perl interface for scripting, and the SXF (Standard eX-change Format), a format for accelerator description which extends the MAD sequence by including deviations from design values. SXF interfaces have been written for several programs, including MAD9 and MAD8 via the doom database, Cosy, TevLat and UAL itself, which includes Teapot++. After an overview of the software we describe the application of the tools to the analysis of the LHC lattice stability, in the presence of alignment and coupling errors, and to the correction of the first turn and closed orbit in the machine. (7 refs)

Beam Based Measurements of Field Multipoles in the RHIC Low Beta Insertions and Extrapolation of the Method to the LHC

The multipolar content of the dipoles and quadrupoles is known to limit the stability of the beam dynamics in super-conducting machines like RHIC and even more in LHC. The low-beta quadrupoles are thus equipped with correcting coils up to the dodecapole order. The correction is planned to rely on magnetic measurements. We show that a relatively simple method allows an accurate measurement of the multipolar field aberrations using the beam. The principle is to displace the beam in the non-linear fields by local closed orbit bumps and to measure the variation of sensitive beam observable. The resolution and robustness of the method are found appropriate. Experimentation at RHIC showed clearly the presence of normal and skew sextupolar field components in addition to a skew quadrupolar component in the interaction regions. Higher-order components up to decapole order appear as well

RHIC heavy ion operations performance

The Relativistic Heavy Ion Collider (RHIC) completed its fifth year of operation in 2005, colliding copper ion beams with ps=200 GeV/u and 62.4 GeV/u[1]. Previous heavy ion runs have collided gold ions at ps=130 GeV/u, 200 GeV/u, and 62.4 GeV/u[2], and deuterons and gold ions at ps=200 GeV/u[3]. This paper discusses operational performance statistics of this facility, including Cu- Cu delivered luminosity, availability, calendar time spent in physics stores, and time between physics stores. We summarize the major factors affecting operations efficiency, and characterize machine activities between physics stores

The roots of terrorism: A reassessment after September 11th

The brutal terrorist attacks of September 11th, the anthrax attacks that followed and growing knowledge of al Qaeda's pursuit of nuclear, biological and chemical weapons have not only intensified concerns about terrorism but also created doubts about our understanding of terrorism. These attacks were in many ways unprecedented, and ultimately raise the question of the roots or causes of terrorism. Historically and today, there have been divergent views on this question, which reflect philosophical, religious, political and other differences. These differences are not merely academic, as they can affect our understanding of both the threat and of responses to terrorism in the aftermath of September 1 1 th. Terrorism is too complex and diverse a phenomenon to speak easily of causes. But we may be able to discern the causes of specific acts. Our response to 9/11 and other acts of terrorism will be affected by our understanding of their causes, as well as by possible political requirements to address widespread perceptions of causes. If 9/11 was caused by Islamic radicalism, the near-term response must be to ensure the terrorists are defeated and pose no fiuther danger. In the longer term, education is critical. If the attacks were caused by US Middle East policies, the response should involve a review of those policies. This may or may not result in changes to policy, public diplomacy, etc. If the attacks were a backlash against globalization, the response must address the realities underlying anti-globalization sentiments. Addressing causes (real and perceived) will not in any case end terrorism, and addressing the wrong causes can be counterproductive. Actions to reduce those conditions that create support for terrorism and aid its recruitment effort are critical to any counterterrorism strategy. For this reason alone, we must do everything possible to understand the reasons terrorism may be undertaken, including the attacks of September 1 1 th. This paper will look at the question of the roots of terrorism and then look to the specific case of 9/11 and its aftermath, with a special view to the impact of globalization

Extrasolar Trojan Planets close to Habitable Zones

We investigate the stability regions of hypothetical terrestrial planets around the Lagrangian equilibrium points L4 and L5 in some specific extrasolar planetary systems. The problem of their stability can be treated in the framework of the restricted three body problem where the host star and a massive Jupiter-like planet are the primary bodies and the terrestrial planet is regarded as being massless. From these theoretical investigations one cannot determine the extension of the stable zones around the equilibrium points. Using numerical experiments we determined their largeness for three test systems chosen from the table of the know extrasolar planets, where a giant planet is moving close to the so-called habitable zone around the host star in low eccentric orbits. The results show the dependence of the size and structure of this region, which shrinks significantly with the eccentricity of the known gas giant.Comment: 4 pages, 4 figures, submitted to A&

A study of the stability regions in the planetary system HD 74156 - Can it host earthlike planets in habitable zones?

Using numerical methods we thoroughly investigate the dynamical stability in the region between the two planets found in HD 74156. The two planets with minimum masses 1.56 M_JUP (HD 74156b) and 7.5 M_JUP (HD 74156c), semimajor axes 0.276 AU and 3.47 AU move on quite eccentric orbits (e=0.649 and 0.395). There is a region between 0.7 and 1.4 AU which may host additional planets which we checked via numerical integrations using different dynamical models. Besides the orbital evolution of several thousands of massless regarded planets in a three-dimensional restricted 4-body problem (host star, two planets + massless bodies) we also have undertaken test computation for the orbital evolution for fictive planets with masses of 0.1, 0.3 and 1 M_JUP in the region between HD74156b and HD74156c. For direct numerical integrations up to 10^7 years we used the Lie-integrator, a method with adaptive stepsize; additionally we used the Fast Lyapunov Indicators as tool for detecting chaotic motion in this region. We emphasize the important role of the inner resonances (with the outer planet) and the outer resonances (with the inner planet) with test bodies located inside the resonances. In these two "resonance" regions almost no orbits survive. The region between the 1:5 outer resonance (0.8 AU) and the 5:1 inner resonance (1.3 AU), just in the right position for habitability, is also very unstable probably due to three-body-resonances acting there. Our results do not strictly "forbid" planets to move there, but the existence of a planet on a stable orbit between 0.8 and 1.3 AU is unlikely.Comment: submitted to A&A, 4 pages, 5 figure

Comparing and Defining Magnetic Multipoles: I. MAD and TEAPOT And II. RHIC Measurements and TEAPOT

The definitions of the magnetic field in MAD and in the standard multipole expansion (SME) used internally by Teapot are different. This note, perhaps for the umpTeenth time, defines the relationship between the two field definitions, assuming that they are in fact referring to the same physical quantity. After this discussion we define the relationship between RHIC's measured multipole coefficients and those of Teapot