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Determination of coupled-lattice properties using turn-by-turn data

Description: A formalism for extracting coupled betatron parameters from multiturn, shock excited, beam position monitor data is described. The most important results are nonperturbative in that they do not rely on the underlying ideal lattice model. Except for damping, which is assumed to be exponential and small enough to be removed empirically, the description is symplectic. As well as simplifying the description, this leads to self-consistency checks that are applied to the data. The most important of these is a {open_quotes}magic ratio{close_quotes} of Fourier coefficients that is required to be a lattice invariant, the same at every beam position monitor. All formulas are applied to both real and simulated data. The real data was acquired June, 1992 at LEP as part of decoupling studies, using the LEP beam orbit measurement system. Simulated data, obtained by numerical tracking (TEAPOT) in the same (except for unknown errors) lattice, agrees well with real data when subjected to identical analysis. For both datasets, deviations between extracted and design parameters and deviations from self-consistency can be accounted for by noise and signal processing limitations. This investigation demonstrates that the LEP beam position system yields reliable local coupling measurements. It can be conservatively assumed that systems of similar design at the SSC and LHC will provide the measurements needed for local decoupling.
Date: December 1, 1992
Creator: Bourianoff, G.; Hunt, S. & Mathieson, D.
Partner: UNT Libraries Government Documents Department

Heat leak performance of SSC collider dipole magnets

Description: The large number of superconducting dipoles in the SSC results in a stringent heat leak budget for each dipole. Ensuring that the dipoles meet this budget is vital to the successful operation or the collider. This work surveys heat leak measurements taken during 4 different magnet string tests. These tests involved both 40 mm and SO mm aperture dipoles. In these experiments the heat leak to the 80 K shield, 20 K shield and cold mass are measured. The results are compared to predictions from a computational thermal model of the dipole cryostat. Discrepancies are seen between the predicted and measured values. Possible explanations for these discrepancies are given.
Date: September 1, 1993
Creator: Weisend, J.G. II; Levin, M.; Franks, D.; Pletzer, R.; Augustynowicz, S.; McInturff, A.D. et al.
Partner: UNT Libraries Government Documents Department

Toward design of the Collider Beam Collimation System

Description: A multi-component beam collimation system for the Superconducting Super Collider is described. System choice justification and design requirements are presented. System consists of targets, scrapers, and collimators with appropriate cooling and radiation shielding. Each component has an independent control for positioning and aligning with respect to the beam. Results of beam loss distribution, energy deposition calculations, and thermal analyses, as well as cost estimate, are presented.
Date: February 1, 1994
Creator: Drozhdin, A.; Mokhov, N.; Soundranayagam, R. & Tompkins, J.
Partner: UNT Libraries Government Documents Department

A method of lines solution of the transient behavior of the helium cooled power leads for the SSC

Description: In this study, a detailed numerical thermal mode of a 6.5 kA power lead for the Superconducting Super Collider has been developed, which was adapted from the dynamic model developed by Schiesser. The transient behavior of the power leads was modeled using, a method of lines (MOL) approach. The model was developed to pmvide a tool for analyzing coolant control strategies as well as an understanding of the behavior of the leads under presumed system transients. Results for a current ramp up to 4970 amps are favorably compared with measurements. Also, a loss of cooling situation is predicted to determine the transient temperature distribution under an off-design condition.
Date: May 1, 1995
Creator: Demko, J.A.; Schiesser, W.E.; Carcagno, R. & McAshan, M.
Partner: UNT Libraries Government Documents Department

Vertex detectors

Description: The purpose of a vertex detector is to measure position and angles of charged particle tracks to sufficient precision so as to be able to separate tracks originating from decay vertices from those produced at the interaction vertex. Such measurements are interesting because they permit the detection of weakly decaying particles with lifetimes down to 10{sup {minus}13} s, among them the {tau} lepton and charm and beauty hadrons. These two lectures are intended to introduce the reader to the different techniques for the detection of secondary vertices that have been developed over the past decades. The first lecture includes a brief introduction to the methods used to detect secondary vertices and to estimate particle lifetimes. It describes the traditional technologies, based on photographic recording in emulsions and on film of bubble chambers, and introduces fast electronic registration of signals derived from scintillating fibers, drift chambers and gaseous micro-strip chambers. The second lecture is devoted to solid state detectors. It begins with a brief introduction into semiconductor devices, and then describes the application of large arrays of strip and pixel diodes for charged particle tracking. These lectures can only serve as an introduction the topic of vertex detectors. Time and space do not allow for an in-depth coverage of many of the interesting aspects of vertex detector design and operation.
Date: July 1, 1992
Creator: Lueth, V.
Partner: UNT Libraries Government Documents Department

Compendation of SSC lattice optics in the presence of dipole field errors: Report of the Correction Element Working Group

Description: The assignment of the Correction Element Working Group (CEWG) is to advance the designs of various candidate correction schemes to a point where they can be compared and distilled down to a single plan. Choosing among, the options often involves consideration of incommensurate factors such as cost, practicality, and theoretical performance. Except for minor issues, the CEWG purpose is to gather and array the facts in a form from which these decisions can be rationally made, but not to make the decisions. The present report analyses various schemes for compensating nonlinear multipole errors in the main arc dipoles of the Superconducting Super Collider. Emphasis is on comparing lumped and distributed compensation, on minimizing the total number of correction elements, and on reducing the sensitivity to closed-orbit errors.
Date: February 1, 1989
Creator: Bintinger, D.; Chao, A. & Forest, E.
Partner: UNT Libraries Government Documents Department

Accidental beam loss in superconducting accelerators: Simulations, consequences of accidents and protective measures

Description: The consequences of an accidental beam loss in superconducting accelerators and colliders of the next generation range from the mundane to rather dramatic, i.e., from superconducting magnet quench, to overheating of critical components, to a total destruction of some units via explosion. Specific measures are required to minimize and eliminate such events as much as practical. In this paper we study such accidents taking the Superconducting Supercollider complex as an example. Particle tracking, beam loss and energy deposition calculations were done using the realistic machine simulation with the Monte-Carlo codes MARS 12 and STRUCT. Protective measures for minimizing the damaging effects of prefire and misfire of injection and extraction kicker magnets are proposed here.
Date: February 1, 1994
Creator: Drozhdin, A.; Mokhov, N. & Parker, B.
Partner: UNT Libraries Government Documents Department

Superconducting Super Collider site environmental report for calendar year 1991. Pre-operational

Description: This is the first annual SER prepared for the SSC project. It is a pre-operational report, intended primarily to describe the baseline characterization of the Ellis County, Texas site that has been developed subsequent to the Environmental Impact Statement (EIS) and the Supplemental Environmental impact Statement (SEIS). As such, the emphasis will be on environmental compliance efforts, including monitoring and mitigation programs. The SER also reports on the measures taken to meet the commitments made in the EIS and SEIS. These measures are detailed in the Mitigation Action Plan (MAP) (Department of Energy (DOE), 1991), which was prepared following the signing of the Record of Decision (ROD) to construct the SSC in Texas. The SER will continue to be preoperational until the first high-energy (20 trillion electron volt or TeV) protons collisions are observed, at which point the SSC will become operational. At that time, the SER will place more emphasis on the radiological monitoring program. This SER will report on actions taken in 1991 or earlier and briefly mention some of those planned for calendar year 1992. AU actions completed in 1992 will be addressed in the SER for calendar year 1992.
Date: May 1, 1995
Partner: UNT Libraries Government Documents Department

Status of superconducting magnets for the Superconducting Super Collider

Description: The arc sections of the High Energy Booster and the two Collider Rings will need more than 10,000, very large, superconducting dipole and quadrupole magnets. Development work on these magnets was carried out at US/DOE laboratories in a program that began in the mid 1980`s. In 1991-1992, the technology was transferred to industry and twenty, full-length, Collider dipoles were successfully fabricated and tested. This program, along with HERA and Tevatron experience, has provided industry a data base to use in formulating detailed designs for the prototypes of the accelerator magnets, with an eye to reducing cost and enhancing producibility. Several model magnets from this latest phase of the industrial program have already been tested. The excessive ramp-rate sensitivity of the magnets is understood and solutions are under investigation.
Date: September 1, 1993
Creator: Schermer, R.I.
Partner: UNT Libraries Government Documents Department

Averaging in the presence of sliding errors

Description: In many cases the precision with which an experiment can measure a physical quantity depends on the value of that quantity. Not having access to the true value, experimental groups are forced to assign their errors based on their own measured value. Procedures which attempt to derive an improved estimate of the true value by a suitable average of such measurements usually weight each experiment`s measurement according to the reported variance. However, one is in a position to derive improved error estimates for each experiment from the average itself, provided an approximate idea of the functional dependence of the error on the central value is known. Failing to do so can lead to substantial biases. Techniques which avoid these biases without loss of precision are proposed and their performance is analyzed with examples. These techniques are quite general and can bring about an improvement even when the behavior of the errors is not well understood. Perhaps the most important application of the technique is in fitting curves to histograms.
Date: August 1, 1991
Creator: Yost, G.P.
Partner: UNT Libraries Government Documents Department

Report of the task force on radioactivation

Description: Estimates have been made of the residual radioactivation of the components of the SSC accelerator and detector complex. Such activation is caused by the loss of a small fraction of the proton beams being transported in the SSC accelerator system, by deliberate removal (dumping) of the beams and by particles created in the proton-proton collisions in the SSC storage rings. Existing methodology that has been successfully used to determine activation levels at other accelerator facilities has also been used to estimate the activation of SSC components in those cases where calculational methods may be applied. In addition, we have used measurements from existing accelerators, primarily the Fermilab and CERN accelerators, to provide the means to estimate activation for those cases in which calculational methods, such as Monte Carlo shower codes, are difficult to apply. We have also used these measurements to check the calculations from the shower codes where possible. We have estimated activation levels and dose rates, where possible, for the following components of the SSC: The abort dumps for both the storage rings and the elements of the injector system; beam Collimators and scrapers; magnets and other apparatus in the region of injection/extraction from one accelerator to another, target stations used to create test beams from the high energy booster; superconducting magnets in the high energy booster and the storage rings; and representative detector elements. We also briefly discuss aspects of handling or dismantling the components most significantly activated and the relevance to decommissioning of the SSC complex. A short description of the decommissioning of the Intersecting Storage Rings at CERN, the only pp collider that has been decommissioned, is included in this report.
Date: October 1, 1987
Partner: UNT Libraries Government Documents Department

Computer simulation of the emittance growth due to noise in large hadron colliders

Description: The problem of emittance growth due to random fluctuations of the magnetic field in a hadron collider is considered. The results of computer simulations are compared with the analytical theory developed earlier. A good agreement was found between the analytical theory predictions and the computer simulations for the collider tunes located far enough from high order betatron resonances. The dependencies of the emittance growth rate on noise spectral density, beam separation at the Interaction Point (IP) and value of beam separation at long range collisions are studied. The results are applicable to the Superconducting Super Collider (SSC).
Date: March 1, 1993
Creator: Lebedev, V.
Partner: UNT Libraries Government Documents Department

The status of detectors at the SSC

Description: The announcement of the location of the SSC at the site near Waxahachie, Texas was made in January, 1989. Since then a great many important steps have been taken toward the start of the new Laboratory. Some 900 people have been brought to the site as the starting nucleus of the staff that will ultimate number about 2200. A design baseline has been completed that includes a conceptual design for the accelerator, and the detectors. Also, the process has begun to determine the configuration of detectors that will be built for the SSC. This process has several steps, and now the first of these has been taken: The detector collaborations have submitted the Expression of Interest to the Laboratory. These were reviewed by Laboratory management and the Physics Advisory Committee in July, 1990 and recommendations were made to the collaborations. Decisions were deferred for all of the detectors. But perhaps the most significant recommendation was the request to reduce the size and cost of the general purpose detectors. The detector collaborations are now reviewing their initial designs to prepare for the Letters of Intent, the next step in the detector planning process. This is clearly a difficult and crucial step in that the redesign of the detectors must be done with minimal reduction in detector quality. It is an interesting time in the development of the new laboratory, and a crucial time for the ultimate physics that will be done at the SSC.
Date: September 1, 1990
Creator: Stefanski, R.
Partner: UNT Libraries Government Documents Department

Collider scenario implications of ASST Operation

Description: After the achievement of the SSCL`s Congressionally Mandated milestone, the Accelerator System String Test (ASST) half cell under went a series of power tests. These tests involved quenches induced in various configurations and in power levels up to the maximum operation point. These tests have produced data which has defined various parameters and requirements for the individual elements and system.
Date: May 1, 1993
Creator: McInturff, A.D.; Burgett, W. & Christianson, M.
Partner: UNT Libraries Government Documents Department

Object-oriented simulation for the Superconducting Super Collider

Description: This paper describes the design and implementation of an object-oriented simulation environment called OZ for the Superconducting Super Collider (SSC). The design applies object-oriented technology to data visualization, behavior modelling, dynamic simulation and version control. A meta class structure is proposed to model different types of objects in large systems by their functionality. OZ provides a direct-manipulation user interface which allows the user to visualize the data as an object in the database and interactively model the component of the system. Modelling can be exercised at different levels of the class hierarchy and then can be dynamically bound into a system for simulation. Inheritance is used to derive new configurations of the system or subsystem from the existing one, and specify an object`s behavior. Delegation is used to construct a system by instantiating existing objects and ``stealing`` their methods by delegators.
Date: October 1, 1992
Creator: Zhou, Jiasheng & Chung, Moon-Jung
Partner: UNT Libraries Government Documents Department

Overview of radiation protection at the Superconducting Super Collider Laboratory

Description: The radiation protection program at the Superconducting Super Collider Laboratory is described. After establishing a set of stringent design guidelines for radiation protection, both normal and accidental beam losses for each accelerator were estimated. From these parameters, shielding requirements were specified using Monte-Carlo radiation transport codes. A groundwater activation model was developed to demonstrate compliance with federal drinking water standards. Finally, the environmental radiation monitoring program was implemented to determine the effect of the facility operation on the radiation environment.
Date: March 1, 1994
Creator: Baker, S.; Britvich, G.; Bull, J.; Coulson, L.; Coyne, J.; Mokhov, N. et al.
Partner: UNT Libraries Government Documents Department

The low energy booster project status

Description: In order to achieve the required injection momentum, the Superconducting Super Collider (SSC) has an accelerator chain comprised of a Linear Accelerator and three synchrotrons. The Low Energy Booster (LEB) is the first synchrotron in this chain. The LEB project has made significant progress in the development of major subsystems and conventional construction. This paper briefly reviews the performance requirements of the LEB and describes significant achievements in each of the major subsystem areas. Highlighted among these achievements are the LEB foreign collaborations with the Budker Institute of Nuclear Physics (BINP) located in Novosibirsk, Russia.
Date: May 1, 1993
Creator: Tuttle, G. W.
Partner: UNT Libraries Government Documents Department

Synchrotron radiation from protons

Description: Synchrotron radiation from protons, though described by the same equations as the radiation from electrons, exhibits a number of interesting features on account of the parameters reached in praxis. In this presentation, we shall point out some of the features relating to (i) normal synchrotron radiation from dipoles in proton machines such as the High Energy Booster and the Superconducting Super Collider; (ii) synchrotron radiation from short dipoles, and its application to light monitors for proton machines, and (iii) synchrotron radiation from undulators in the limit when, the deflection parameter is much smaller than unity. The material for this presentation is taken largely from the work of Hofmann, Coisson, Bossart, and their collaborators, and from a paper by Kim. We shall emphasize the qualitative aspects of synchrotron radiation in the cases mentioned above, making, when possible, simple arguments for estimating the spectral and angular properties of the radiation. Detailed analyses can be found in the literature.
Date: December 1, 1992
Creator: Dutt, S.K.
Partner: UNT Libraries Government Documents Department

Trigger and DAQ issues in low-mass Higgs searches

Description: Results from ongoing trigger and DAQ studies at the Superconducting Super Collider Laboratory are presented. Specific Higgs decay modes are identified, calorimetric triggering algorithms are examined, and implications for data acquisition are discussed.
Date: October 1, 1992
Creator: Wang, E.M.; Botlo, M.; Dorenbosch, J. & Walbran, S.
Partner: UNT Libraries Government Documents Department

A 40 GByte/s read-out system for GEM

Description: The preliminary design of the read-out system for the GEM (Gammas, Electrons, Muons) detector at the Superconducting Super Collider is presented. The system reads all digitized data from the detector data sources at a Level 1 trigger rate of up to 100 kHz. A total read-out bandwidth of 40 GBytes/s is available. Data are stored in buffers that are accessible for further event filtering by an on-line, processor farm. Data are transported to the farm only as they are needed by the higher-level trigger algorithms, leading to a reduced bandwidth requirement in the Data Acquisition System.
Date: April 1994
Creator: Bowden, M.; Carrel, J.; Dorenbosch, J. & Kapoor, V.
Partner: UNT Libraries Government Documents Department

Perturbation approach and the constant of motion for on-dimensional dynamical systems

Description: A perturbation technic is used to find the constant of motion of a one-dimensional autonomous system. The convergence of the method is discussed through some examples. In addition, the approach is extended to one-dimensional non-autonomous systems where some examples are given.
Date: November 1, 1991
Creator: Lopez, G.
Partner: UNT Libraries Government Documents Department

Computer protection plan for the Superconducing Super Collider Laboratory

Description: The purpose of this document is to describe the current unclassified computer security program practices, Policies and procedures for the Superconducting Super Collider Laboratory (SSCL). This document includes or references all related policies and procedures currently implemented throughout the SSCL. The document includes security practices which are planned when the facility is fully operational.
Date: April 15, 1992
Creator: Hunter, S.
Partner: UNT Libraries Government Documents Department