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The Longitudinal Stability of Intense Non-Relativistic Particle Bunches in Resistive Structures

Description: The longitudinal stability of intense particle bunches is investigated theoretically in the limit of small wall resistivity compared to total reactance. It is shown that both in the absence of resistivity and to lowest order in the resistance that an intense bunch is stable against longitudinal collective modes. An expression is derived for the lowest order instability rate. Application of these results are made to drivers for heavy ion inertial fusion.
Date: February 1, 1981
Creator: Channell, P. J.; Sessler, A. M. & Wurtele, J. S.
Partner: UNT Libraries Government Documents Department

Sensor Development and Readout Prototyping for the STAR Pixel Detector

Description: The STAR experiment at the Relativistic Heavy Ion Collider (RHIC) is designing a new vertex detector. The purpose of this upgrade detector is to provide high resolution pointing to allow for the direct topological reconstruction of heavy flavor decays such as the D{sup 0} by finding vertices displaced from the collision vertex by greater than 60 microns. We are using Monolithic Active Pixel Sensor (MAPS) as the sensor technology and have a coupled sensor development and readout system plan that leads to a final detector with a <200 {micro}s integration time, 400 M pixels and a coverage of -1 < {eta} < 1. We present our coupled sensor and readout development plan and the status of the prototyping work that has been accomplished.
Date: January 14, 2009
Creator: Greiner, L.; Anderssen, E.; Matis, H.S.; Ritter, H.G.; Stezelberger, T.; Szelezniak, M. et al.
Partner: UNT Libraries Government Documents Department

Exposing the non-collectivity in elliptic flow

Description: We show that backward-forward elliptic asymmetry correlations provide an experimentally accessible observable which distinguishes between collective and non-collective contributions to the observed elliptic asymmetry v2 in relativistic heavy ion collisions. The measurement of this observable will reveal the momentum scale at which collective expansion seizes and where the elliptic asymmetry is dominated by (semi)-hard processes. In addition, the knowledge of the actual magnitude of the collective component of the elliptic asymmetry will be essential for the extraction of the viscosity of the matter created in these collisions.
Date: February 13, 2009
Creator: Liao, Jinfeng & Koch, Volker
Partner: UNT Libraries Government Documents Department

Exact Relativistic Ideal Hydrodynamical Solutions in (1+3)D with Longitudinal and Transverse Flows

Description: A new method for solving relativistic ideal hydrodynamics in (1+3)D is developed. Longitudinal and transverse radial flows are explicitly embedded into the ansatz for velocity field and the hydrodynamic equations are reduced to a single equation for the transverse velocity field only, which is analytically more tractable as compared with the full hydrodynamic equations. As an application we use the method to find analytically all possible solutions whose transverse velocity fields have power dependence on proper time and transverse radius. Possible application to the Relativistic Heavy Ion Collisions and possible generalizations of the method are discussed.
Date: May 20, 2009
Creator: Liao, Jinfeng & Koch, Volker
Partner: UNT Libraries Government Documents Department

Longitudinal Resistive Stability of an Intense Charge Bunch in a Linear Accelerator

Description: A simple, but realistic, model is used to theoretically investigate the longitudinal stability of a non-relativistic bunch in the limit of small wall resistivity compared to self-reactance. It is shown that to lowest order--and in contrast with an infinitely long beam--that an intense bunch is stable against longitudinal collective modes. It is concluded that an induction linac remains a viable option as a driver for heavy ion inertial fusion.
Date: July 1, 1980
Creator: Channell, P.J.; Wurtele, J.S. & Sessler, A.M.
Partner: UNT Libraries Government Documents Department

Planning for an integrated research experiment

Description: We describe the goals and research program leading to the Heavy Ion Integrated Research Experiment (IRE). We review the basic constraints which lead to a design and give examples of parameters and capabilities of an IRE. We also show design tradeoffs generated by the systems code IBEAM.
Date: March 25, 2001
Creator: Barnard, J.J.; Ahle, L.E.; Bangerter, R.O.; Bieniosek, F.M.; Celata, C.M.; Faltens, A. et al.
Partner: UNT Libraries Government Documents Department

Fragmentation cross sections of 28Si at beam energies from 290AMeV to 1200A MeV

Description: In planning for long-duration spaceflight, it will beimportant to accurately model the exposure of astronauts to heavy ions inthe Galactic Cosmic Rays (GCR). As part of an ongoing effort to improveheavy-ion transport codes that will be used in designing futurespacecraft and habitats, fragmentation cross sections of 28Si have beenmeasured using beams with extracted energies from 290A MeV to 1200A MeV,spanning most of the peak region of the energy distribution of siliconions in the GCR. Results were obtained for six elemental targets:hydrogen, carbon, aluminum, copper, tin, and lead. The charge-changingcross sections are found to be energy-independent within the experimentaluncertainties, except for those on the hydrogen target. Cross sectionsfor the heaviest fragments are found to decrease slightly with increasingenergy for lighter targets, but increase with energy for tin and leadtargets. The cross sections are compared to previous measurements atsimilar energies, and to predictions of the NUCFRG2 model used by NASA toevaluate radiation exposures in flight. For charge-changing crosssections, reasonable agreement is found between the present experimentand those of Webber, et al. and Flesch, et al., and NUCFRG2 agrees withthe data to within 3 percent in most cases. Fragment cross sections showless agreement between experiments, and there are substantial differencesbetween NUCFRG2 predictions andthe data.
Date: August 25, 2006
Creator: Zeitlin, C.; Fukumura, A.; Guetersloh, S.B.; Heilbronn, L.H; Iwata, Y.; Miller, J. et al.
Partner: UNT Libraries Government Documents Department

Highly-charged heavy-ion production with short pulse lasers

Description: This MathCAD document describes a possible approach using a PW -class short pulse laser to form a useful number (10{sup 12}) of high and uniform charge state ions with low ion temperature (<< 100 eV) and low momentum spread ({delta}p{sub z}/p, < 10{sup -4} ) for injection into heavy-ion fusion accelerators. As a specific example, we consider here Xenon{sup +26}, which has an ionization energy E{sub i} {approximately} 860 eV for the 26th electron, and a significantly higher ionization potential of 1500 eV for the 27th electron because of the M-shell jump. The approach considered here may be used for other ion species as well. The challenge is not simply to produce high charge states with a laser (the ITEP group [Sharkov] have used long pulse CO{sub 2} lasers to create many charge states of chromium up to helium-like Cr{sup +25} by collisional ionization at high Te), nor just to create such high charge states more selectively by field (tunneling) ionization at higher intensities and shorter pulses. Rather, the challenge is to create a selected uniform high charge state, in useful numbers, while keeping the ion temperature and momentum spread small, and avoiding subsequent loss of ion charge state due to recombination and charge-exchange with background gas atoms during extraction into a useful low emittance beam.
Date: January 27, 1998
Creator: Logan, G.; Bitmire, T.; Perry, M.; Anderson, O. & Kuehl, T.
Partner: UNT Libraries Government Documents Department

Hadronic Correlations and Fluctuations

Description: We will provide a review of some of the physics which can be addressed by studying fluctuations and correlations in heavy ion collisions. We will discuss Lattice QCD results on fluctuations and correlations and will put them into context with observables which have been measured in heavy-ion collisions. Special attention will be given to the QCD critical point and the first order co-existence region, and we will discuss how the measurement of fluctuations and correlations can help in an experimental search for non-trivial structures in the QCD phase diagram.
Date: October 9, 2008
Creator: Koch, Volker
Partner: UNT Libraries Government Documents Department

Strangelet Search at the BNL Relativistic Heavy Ion Collider

Description: We have searched for strangelets in a triggered sample of 61 million central (top 4percent) Au+Au collisions at sqrt sNN = 200 GeV near beam rapidities at the STAR solenoidal tracker detector at the BNL Relativistic Heavy Ion Collider. We have sensitivity to metastable strangelets with lifetimes of order&gt;_0.1 ns, in contrast to limits over ten times longer in BNL Alternating Gradient Synchrotron (AGS) studies and longer still at the CERN Super Proton Synchrotron (SPS). Upper limits of a few 10-6 to 10-7 per central Au+Au collision are set for strangelets with mass&gt;~;;30 GeV/c2.
Date: November 27, 2005
Creator: Ritter, Ha
Partner: UNT Libraries Government Documents Department

Correlations and Fluctuations: Status and Perspectives

Description: We will provide an overview of the physics which can be addressed by studying fluctuations and correlations in heavy ion collisions. Observables, which have been discussed in the literature will be briefly reviewed and put in context with experiment and information from Lattice QCD. Special attention will be given to the QCD critical point and the first order co-existence region.
Date: April 15, 2008
Creator: Koch, Volker & Koch, Volker
Partner: UNT Libraries Government Documents Department

Compact High-Current Heavy-Ion Injector

Description: To provide a compact high-brightness heavy-ion beam source for Heavy Ion Fusion (HIF), we have been experimenting with merging multi-beamlets in an injector which uses an RF plasma source. An array of converging beamlets was used to produce a beam with the envelope radius, convergence, and ellipticity matched to an electrostatic quadrupole (ESQ) channel. Experimental results were in good quantitative agreement with simulation and have demonstrated the feasibility of this concept. The size of a driver-scale injector system using this approach will be several times smaller than one designed using traditional single large-aperture beams. The success of this experiment has possible significant economical and technical impacts on the architecture of HIF drivers.
Date: October 5, 2005
Creator: Westenskow, G. A.; Grote, D. P.; Kwan, J. W. & Bieniosek, F.
Partner: UNT Libraries Government Documents Department

Laser ion source for low charge heavy ion beams

Description: For heavy ion inertial fusion application, a combination of a laser ion source and direct plasma injection scheme into an RFQ is proposed. The combination might provide more than 100 mA of singly charged heavy ion beam from a single laser shot. A planned feasibility test with moderate current is also discussed.
Date: August 3, 2008
Creator: Okamura, M.; Pikin, A.; Zajic, V.; Kanesue, T. & Tamura, J.
Partner: UNT Libraries Government Documents Department

A LOW GAMMA_T INJECTION LATTICE FOR POLARIZED PROTONS IN RHIC

Description: Polarized protons are injected into the Relativistic Heavy Jon Collider (RHIC) just above transition energy. When installation of a cold partial Siberian snake in the AGS required lowering the injection energy by {Delta}{gamma} = 0.56, the transition energy in RHIC had to be lowered accordingly to ensure proper longitudinal matching. This paper presents lattice modifications implemented to lower the transition energy by {Delta}{gamma}{sub t} = 0.8.
Date: June 25, 2007
Creator: MONTAG,C.
Partner: UNT Libraries Government Documents Department

The Ridge, the Glasma and Flow

Description: I discuss the ridge phenomena observed in heavy ion collisions at RHIC. I argue that the ridge may be due to flux tubes formed from the Color Glass Condensate in the early Glasma phase of matter produced in such collisions.
Date: September 15, 2008
Creator: McLerran,L.
Partner: UNT Libraries Government Documents Department

OBSERVATION OF EXPERIMENTAL BACKGROUND IN RHIC POLARIZED PROTON RUN 2006.

Description: The beam-gas has affected STAR background in RHIC proton Run 2005, but not in Run 2006. With higher beam intensity in Run 2008, the beam-gas effect at STAR may be of concern. The ratio of ZDC background and coincident rate seems to be useful in proton runs in evaluating the experimental background.
Date: June 25, 2007
Creator: ZHANG,S. & TRBOJEVIC, D.
Partner: UNT Libraries Government Documents Department

T.D. LEE: RELATIVISTIC HEAVY ION COLLISIONS AND THE RIKEN BROOKHAVEN CENTER.

Description: This paper presents the history of Professor T. D. Lee's seminal work on the theory of relativistic heavy ion collisions, and the founding and development of the Riken Brookhaven Center. A number of anecdotes are given about Prof. Lee, and his strong positive effect on his colleagues, particularly young physicists.
Date: November 24, 2006
Creator: MCLERRAN,L. & SAMIOS, N.
Partner: UNT Libraries Government Documents Department

Feedback damper system for quadrupole oscillations after transition at RHIC.

Description: The heavy ion beam at RHIC undergoes strong quadrupole oscillations just after it crosses transition, which leads to an increase in bunch length making rebucketing less effective. A feedback system was built to damp these quadrupole oscillations and in this paper the characteristics of the system and the results obtained are presented and discussed.
Date: June 23, 2008
Creator: Abreu,N.; Blaskiewicz, M.; Brennan, J.M. & Schultheiss, C.
Partner: UNT Libraries Government Documents Department

Complete fabrication of target experimental chamber and implement initial target diagnostics to be used for the first target experiments in NDCX-1

Description: The Heavy Ion Fusion Science Virtual National Laboratory (HIFS-VNL) has completed the fabrication of a new experimental target chamber facility for future Warm Dense Matter (WDM) experiments, and implemented initial target diagnostics to be used for the first target experiments in NDCX-1. The target chamber has been installed on the NDCX-I beamline. This achievement provides to the HIFS-VNL unique and state-of-the-art experimental capabilities in preparation for the planned target heating experiments using intense heavy ion beams.
Date: June 9, 2008
Creator: Bieniosek, F.M.; Bieniosek, F.M.; Dickinson, M.R.; Henestroza, E.; Katayanagi, T.; Jung, J.Y. et al.
Partner: UNT Libraries Government Documents Department

Ultra-Relativistic Heavy Ion Nuclear Physics

Description: This report describes an on-going research initiative for the University of Arkansas at Little Rock (UALR): investigating the physics of ultra-relativistic heavy ions, i.e. collisions between massive nuclei which have been accelerated to kinetic energies so large that the rest mass of the ions is a negligible fraction of their total mass-energy. This progress report is being submitted in conjunction with a 3-year grant-renewal proposal, containing additional materials. Three main categories drive the UALRGultra-relativistic heavy ion research. (1) investigations of multi-particle Hanbury-Brown-Twiss (HBT) correlations in the CERN and RHIC energy domains strongly influence the URHI experimental effort, (2) participation in the NA49 Experiment to study 33 TeV (160 GeV/nucleon) Pb on Pb collisions using the SPS facili& at CERN, and (3) participation in the STAR collaboration which is developing a major detector for use with the STAR Experiment at the Relativistic Heavy Ion Collider (RHIC), being built at BNL.
Date: May 31, 1995
Creator: Braithwaite, W. J.
Partner: UNT Libraries Government Documents Department