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The transport line between the main ring and the energy doubler

Description: In this paper we describe the transport line between the main ring (MR) and the energy doubler (ED). The transport line is designed on the basis of the following three assumptions: (1) The ED is located at the apex of the same tunnel which encloses the MR. The relative locations of the two rings are shown in Fig. 1. The ED line is 3 feet to the inside and 4 feet above with respect to the MR line. Watching Fig. 1 the beam moves toward the page and the center of the rings is to the right. The continuous outer curve is the cross section of the tunnel in a typical long-straight section, the dashed inner curve is the cross section of the tunnel in the bent section. (2) The beam has to be extracted from one long-straight section of the MR (BO) and injected in the next medium-straight section of the ED (B17). The two rings are assumed to have the same identical lattice structure. (3) To keep the aisle-way in the tunnel as clear as we can it is advisable to extract the beam horizontally but displaced first vertically upward and second horizontally inward. The beam is then injected vertically. To avoid problems associated with trapped flux at low fields, it is advisable to inject at an energy substantially higher than 100 GeV. On the other hand, the last two assumptions limit the maximum energy to about 200 GeV. For higher energy one has, at the same time, to transfer the beam from one long-straight section to the next long-straight section and to obstruct a good fraction of the tunnel with Ragnets. Thus, the transport line we are going to describe here, has been designed for the transfer energy of 200 GeV. The transport line is divided in ...
Date: July 1, 1974
Creator: Ruggiero, A.G.
Partner: UNT Libraries Government Documents Department

Adiabatic capture and debunching

Description: In the study of beam preparation for the g-2 experiment, adiabatic debunching and adiabatic capture are revisited. The voltage programs for these adiabbatic processes are derived and their properties discussed. Comparison is made with some other form of adiabatic capture program. The muon g-2 experiment at Fermilab calls for intense proton bunches for the creation of muons. A booster batch of 84 bunches is injected into the Recycler Ring, where it is debunched and captured into 4 intense bunches with the 2.5-MHz rf. The experiment requires short bunches with total width less than 100 ns. The transport line from the Recycler to the muon-production target has a low momentum aperture of {approx} {+-}22 MeV. Thus each of the 4 intense proton bunches required to have an emittance less than {approx} 3.46 eVs. The incoming booster bunches have total emittance {approx} 8.4 eVs, or each one with an emittance {approx} 0.1 eVs. However, there is always emittance increase when the 84 booster bunches are debunched. There will be even larger emittance increase during adiabatic capture into the buckets of the 2.5-MHz rf. In addition, the incoming booster bunches may have emittances larger than 0.1 eVs. In this article, we will concentrate on the analysis of the adiabatic capture process with the intention of preserving the beam emittance as much as possible. At this moment, beam preparation experiment is being performed at the Main Injector. Since the Main Injector and the Recycler Ring have roughly the same lattice properties, we are referring to adiabatic capture in the Main Injector instead in our discussions.
Date: March 1, 2012
Creator: Ng, K. Y.
Partner: UNT Libraries Government Documents Department

A new approach to calculate the transport matrix in RF cavities

Description: A realistic approach to calculate the transport matrix in RF cavities is developed. It is based on joint solution of equations of longitudinal and transverse motion of a charged particle in an electromagnetic field of the linac. This field is a given by distribution (measured or calculated) of the component of the longitudinal electric field on the axis of the linac. New approach is compared with other matrix methods to solve the same problem. The comparison with code ASTRA has been carried out. Complete agreement for tracking results for a TESLA-type cavity is achieved. A corresponding algorithm will be implemented into the MARS15 code. A realistic approach to calculate the transport matrix in RF cavities is developed. Complete agreement for tracking results with existed code ASTRA is achieved. New algorithm will be implemented into MARS15 code.
Date: March 1, 2011
Creator: Eidelman, Yu.; /Novosibirsk, IYF; Mokhov, N.; Nagaitsev, S.; Solyak, N. & /Fermilab
Partner: UNT Libraries Government Documents Department

Bunch Coalescing in a Helical Channel

Description: A high-luminosity Muon Collider requires bunch recombination for optimal luminosity. In this paper, we take advantage of the large slip factor attainable in a helical transport channel (HTC) to coalesce bunches of muons into a single one over a shorter distance than can be achieved over a straight channel.
Date: May 1, 2012
Creator: Neuffer, D.V.; Yonehara, K.; /Fermilab; Ankenbrandt, C.M.; Yoshikawa, C.Y. & /MUONS Inc., Batavia
Partner: UNT Libraries Government Documents Department

Finding the Magnetic Center of a Quadrupole to High Resolution

Description: In a companion pro, collposal it is proposed to align quadrupoles of a transport line to within transverse tolerances of 5 to 10 micrometers. Such a proposal is meaningful only if the effective magnetic center of such lenses can in fact be repeatably located with respect to some external mechanical tooling to comparable accuracy. It is the purpose of this note to describe some new methods and procedures that will accomplish this aim. It will be shown that these methods are capable of yielding greater sensitivity than the more traditional methods used in the past. The notion of the ''nodal'' point is exploited.
Date: August 12, 2005
Creator: Fischer, G.E.; Cobb, J.K.; Jenson, D.R. & /SLAC
Partner: UNT Libraries Government Documents Department

LCLS Injector Drive Laser

Description: Requirements for the LCLS injector drive laser present significant challenges to the design of the system. While progress has been demonstrated in spatial shape, temporal shape, UV generation and rep-rate, a laser that meets all of the LCLS specifications simultaneously has yet to be demonstrated. These challenges are compounded by the stability and reliability requirements. The drive laser and transport system has been installed and tested. We will report on the current operational state of the laser and plans for future improvements.
Date: November 2, 2007
Creator: Dowell, D.H.; Castro, J.; Emma, P.; Frisch, J.; Gilevich, A.; Hays, G. et al.
Partner: UNT Libraries Government Documents Department

Transatlantic transport of Fermilab 3.9 GHz cryomodule for TTF/FLASH to DESY

Description: In an exchange of technology agreement, Fermilab built and will deliver a 3.9 GHz (3rd harmonic) cryomodule to DESY to be installed in the TTF/FLASH beamline. This cryomodule delivery will involve a combination of flatbed air ride truck and commercial aircraft transport to Hamburg Germany. A description of the isolation and damping systems that maintain alignment during transport and protect fragile components is provided. Initially, transport and corresponding alignment stability studies were performed in order to assess the risk associated with transatlantic travel of a fully assembled cryomodule. Shock loads were applied to the cryomodule by using a coldmass mockup to prevent subjecting actual critical components (such as the cavities and input couplers) to excessive forces. Accumulative and peak shock loads were applied through over-the-road testing and using a pendulum hammer apparatus, respectively. Finite Element Analysis (FEA) studies were implemented to define location of instrumentation for transport studies and provide modal frequencies and shapes. Shock and vibration measurement results of transport studies and stabilization techniques are discussed.
Date: June 1, 2008
Creator: McGee, M.W.; Vocean, V.; Grimm, C.; Schappert, W. & /Fermilab
Partner: UNT Libraries Government Documents Department

Muon cooling in a quadrupole magnet channel

Description: As discussed before,[1] a cooling channel using quadrupole magnets in a FODO transport channel can be used for initial cooling of muons. In the present note we discuss this possibility of a FODO focusing channel for cooling, and we present ICOOL simulations of muon cooling within a FODO channel. We explore a 1.5m cell-length cooling channel that could be used for the initial transverse cooling stage of a muon collider or neutrino factory.
Date: October 1, 2007
Creator: Neuffer, David; /Fermilab; Poklonskiy, A. & U., /Michigan State
Partner: UNT Libraries Government Documents Department

Study of effects of deformation in Nb3Sn multifilamentary strands

Description: In the process that leads a flawless Nb{sub 3}Sn round strand to become part of a Rutherford cable first, and of a coil next, the same cabling process affects strands of different kinds in different ways, from filament shearing to subelement merging to composite decoupling. Due to plastic deformation, after cabling the filament size distributions in a strand usually change. The average filament size typically increases, as does the width of the distribution. This is consistent with the low field transport current of strands in cables being typically lower and less reproducible than for round strands [1]. To better understand the role of filament size in instabilities and to simulate cabling deformations, strands to be used in cables can be tested by rolling them down to decreasing sizes to cover an ample range of relative deformations. A procedure is herein proposed that uses both microscopic analysis and macroscopic measurements of material properties to study the effects of deformation.
Date: August 1, 2006
Creator: Turrioni, D.; Barzi, E.; Bossert, R.; Kashikhin, V.V.; /Fermilab; Kikuchi, A. et al.
Partner: UNT Libraries Government Documents Department

Voltage spikes in Nb3Sn and NbTi strands

Description: As part of the High Field Magnet program at Fermilab several NbTi and Nb{sub 3}Sn strands were tested with particular emphasis on the study of voltage spikes and their relationship to superconductor instabilities. The voltage spikes were detected under various experimental conditions using voltage-current (V-I) and voltage-field (V-H) methods. Two types of spikes, designated ''magnetization'' and ''transport current'' spikes, have been identified. Their origin is most likely related to magnetization flux jump and transport current redistribution, respectively. Many of the signals observed appear to be a combination of these two types of spikes; the combination of these two instability mechanisms should play a dominant role in determining the minimum quench current.
Date: September 1, 2005
Creator: Bordini, B.; Ambrosio, G.; Barzi, E.; Carcagno, R.; Feher, S.; Kashikhin, V.V. et al.
Partner: UNT Libraries Government Documents Department

Design of Extraction Line Optics for the ILCInteraction Regions with 20 mrad and 2 mrad Crossing Angles

Description: The studies of the ILC extraction line design have been carried out by the SLAC-BNL-UK-France task force collaboration. In this paper, we describe two options of the extraction optics for the 20 mrad horizontal crossing angle in the Interaction Region (IR), and one option of the 2 mrad extraction optics. The main functions of the extraction line are to transport the primary beam and beamstrahlung photons to dumps with acceptable beam loss, and to provide the necessary optics for beam diagnostics. The presented 20 mrad and 2 mrad optics are designed for up to 1 TeV and 0.5 TeV Center of Mass (CM) energy, respectively. The upgrade of this 2 mrad design to 1 TeV CM and a separate version of the 2 mrad design are presented in a separate report [1].
Date: July 27, 2005
Creator: Nosochkov, Y.; Moffeit, K.; Seryi, A.; Spencer, C.; Wood, M.; /SLAC et al.
Partner: UNT Libraries Government Documents Department

Use of Helical Transport Channels for Bunch Recombination

Description: Cooling scenarios for a high-luminosity Muon Collider require bunch recombination for optimal luminosity. In this report we note that the tunable chronicity property of a helical transport channel (HTC) makes it a desirable component of a bunch recombiner. A large chronicity HTC is desirable for the bunch recombining transport, while more isochronous transport may be preferred for rf manipulations. Scenarios for bunch recombination are presented, with initial 1-D simulations, in order to set the stage for future 3-D simulation and optimization. HTC transports may enable a very compact bunch recombiner.
Date: March 1, 2010
Creator: Neuffer, David; Yonehara, Katsuya; /Fermilab; Yoshikawa, Cary & /MUONS Inc., Batavia
Partner: UNT Libraries Government Documents Department

Anomalous Diffusion Near Resonances

Description: Synchro-betatron resonances can lead to emittance growth and the loss of luminosity. We consider the detailed dynamics of a bunch near such a low order resonance driven by crossing angles at the collision points. We characterize the nature of diffusion and find that it is anomalous and sub-diffusive. This affects both the shape of the beam distribution and the time scales for growth. Predictions of a simplified anomalous diffusion model are compared with direct simulations. Transport of particles near resonances is still not a well understood phenomenon. Often, without justification, phase space motion is assumed to be a normal diffusion process although at least one case of anomalous diffusion in beam dynamics has been reported [1]. Here we will focus on the motion near synchro-betatron resonances which can be excited by several means, including beams crossing at an angle at the collision points as in the LHC. We will consider low order resonances which couple the horizontal and longitudinal planes, both for simplicity and to observe large effects over short time scales. While the tunes we consider are not practical for a collider, nonetheless the transport mechanisms we uncover are also likely to operate at higher order resonances.
Date: May 1, 2010
Creator: Sen, Tanaji
Partner: UNT Libraries Government Documents Department

Design of an 8 GeV h transport and multi-turn injection system

Description: An 8 GeV superconducting linear accelerator (SCL) has been proposed as a single stage H{sup -} injector into the Main Injector (MI) synchrotron. This could be a multi-use facility which would, among other things, support a 2 MW Neutrino program at Fermi National Accelerator Lab (FNAL) [1,2,3,4]. This paper describes a solution for a transport line which is capable of low loss transmission of an H{sup -} beam from the linac to the MI, transverse and momentum collimation, and provides for flexible matching into the MI lattice. The required modifications to the MI accelerator complex to accommodate the transfer line and multi-turn injection utilizing carbon foil stripping (and/or potentially laser stripping) and the injection layout are discussed.
Date: August 1, 2006
Creator: Johnson, D.E.
Partner: UNT Libraries Government Documents Department

High energy H- ion transport and stripping

Description: During the Proton Driver design study based on an 8 GeV superconducting RF H{sup -} linac, a major concern is the feasibility of transport and injection of high energy H{sup -} ions because the energy of H{sup -} beam would be an order of magnitude higher than the existing ones. This paper will focus on two key technical issues: (1) stripping losses during transport (including stripping by blackbody radiation, magnetic field and residual gases); (2) stripping efficiency of carbon foil during injection.
Date: May 1, 2005
Creator: Chou, W.
Partner: UNT Libraries Government Documents Department

NuMI proton beam diagnostics and control: achieving 2 megawatt capability

Description: The NuMI proton beam at Fermilab currently delivers 120 GeV protons to the neutrino production target with design beam power capability to 400 kW. Upgrade capability to 700 kW is being prepared, with planning toward delivering 2.3 MW beam provided by the Project X accelerator upgrade plan. We report on the system of beam diagnostics and control used in operation of the NuMI beam. Also considered are the steps to provide a robust system for transport and targeting beam of 2 MW and beyond.
Date: October 1, 2008
Creator: Childress, S.
Partner: UNT Libraries Government Documents Department

The conceptual design of a new transfer line from booster to recycler for the Fermilab Proton plan phase 2 campaign

Description: Upon the termination of the Fermilab Collider program, the current Recycler anti-proton storage ring (RR) will be converted to a proton pre-injector for the Main Injector (MI) synchrotron. This is scheduled to increase the beam power for the 120 GeV Neutrino program to upwards of 700KW. A transport line that can provide direct injection from the Booster to the Recycler while preserving direct injection from the Booster into the Main Injector and the 8 GeV Booster Neutrino program will be discussed, and its concept design will be presented.
Date: June 1, 2007
Creator: Johnson, D. E. & Xiao, M.
Partner: UNT Libraries Government Documents Department

Cylindric electron envelope for relativistic electron cooling

Description: Electron cooling requires small angles between the electrons and the cooled particles. In other words, the electron beam has to be of a cylindrical shape in the cooling section. How to satisfy this requirement for a specific case of a relativistic electron beam transport for the Fermilab electron cooling project? In fact, the requirement splits into two parts: for the beam centroid and its envelope. A straight centroid motion means a good field quality and zero initial conditions; this issue is not a subject of this paper. The cylindrical envelope requires proper initial conditions of the envelope at the entrance of the cooler, it is a problem of matching. A specific complex of measurements and calculations aimed at solving this problem is described here.
Date: February 1, 2005
Creator: Burov, A.; Lebedev, V. & /Fermilab
Partner: UNT Libraries Government Documents Department

Magnetic instabilities in Nb3Sn strands and cables

Description: This paper describes a model for calculation of magnetic instabilities in superconducting wires with transport current and reports results of instability simulations in Nb{sub 3}Sn strands from different manufactures. The effect of magnetic instabilities on the strand and cable performance is presented and a criterion for the maximum effective sub-element size of strands for high field magnets is formulated.
Date: November 1, 2004
Creator: Kashikhim, Vadim V.; Zlobin, Alexander V. & /Fermilab
Partner: UNT Libraries Government Documents Department

Muon capture for the front end of a muon collider

Description: We discuss the design of the muon capture front end for a {mu}{sup +}-{mu}{sup -} Collider. In the front end, a proton bunch on a target creates secondary pions that drift into a capture transport channel, decaying into muons. A sequence of rf cavities forms the resulting muon beams into strings of bunches of differing energies, aligns the bunches to (nearly) equal central energies, and initiates ionization cooling. The muons are then cooled and accelerated to high energy into a storage ring for high-energy high luminosity collisions. Our initial design is based on the somewhat similar front end of the International Design Study (IDS) neutrino factory.
Date: March 1, 2011
Creator: Neuffer, D.; /Fermilab; Yoshikawa, C. & /MUONS Inc., Batavia
Partner: UNT Libraries Government Documents Department

Focusing solenoids for the HINS Linac front end

Description: The low energy part of a linac for the High Intensity Neutrino Source (HINS) project at Fermilab will use superconducting solenoids as beam focusing elements (lenses). While the lenses for the conventional DTL-type accelerating section of the front end require individual cryostats, in the superconducting accelerating sections solenoids will be installed inside RF cryomodules. Some of the lenses in the conventional and in the superconducting sections are equipped with horizontal and vertical steering dipoles. Lenses for the DTL section are in the stage of production with certification activities ongoing at Fermilab. For the superconducting sections of the linac, a prototype lens has been built and tested. Each lens will be installed in the transport channel of the accelerator so that its magnetic axis is on the beamline. Corresponding technique has been developed at Fermilab and is used during the certification process. This report summarizes design features, parameters, and test results of the focusing lenses.
Date: October 1, 2008
Creator: Terechkine, I.; Appollinari, G.; Di-Marco, J.; Huang, Y.; Orris, D.; Page, T. et al.
Partner: UNT Libraries Government Documents Department

Initial Search for 9-keV XTR from a 28-GeV Beam at SPPS

Description: The potential to use x-ray transition radiation (XTR) as a beam diagnostic and coherent XTR (CXTR) as a gain diagnostic in an x-ray FEL was proposed previously. At that time we noted that the unique configuration of the SLAC Sub-picosecond Photon Source (SPPS) with its known x-ray wiggler source, a special three-element x-ray monochromator, x-ray transport line, and experimental end station with x-ray detectors made it an ideal location for an XTR feasibility experiment. Estimates of the XTR compared to the SPPS source strength were done, and initial experiments were performed in September 2005. Complementary measurements on optical transition radiation (OTR) far-field images from a 7-GeV beam are also discussed.
Date: April 16, 2007
Creator: Lumpkin, A.H.; /Argonne; Hastings, J.B.; /SLAC; Rule, D.W. & Ctr., /Naval Surface Warfare
Partner: UNT Libraries Government Documents Department

SABER Optical Design

Description: SABER, the South Arc Beam Experimental Region, is a proposed new beam line facility designed to replace the Final Focus Test Beam at SLAC. In this paper, we outline the optical design features and beam parameters now envisioned for SABER. A magnetic chicane to compress positron bunches for SABER and a bypass line that could transport electrons or positrons from the two-thirds point of the linac to SABER, bypassing the LCLS systems, are also discussed.
Date: July 7, 2006
Creator: Erickson, R.; Bane, K.; Emma, P.; Nosochkov, y. & /SLAC
Partner: UNT Libraries Government Documents Department

Isochronous pion decay channel for enhanced muon capture

Description: Intense muon beams have many potential applications, including neutrino factories and muon colliders. However, muons are produced in tertiary beams into a diffuse phase space. To make useful beams, the muons must be rapidly cooled before they decay. A promising new concept for the collection and cooling of muon beams is being investigated, namely, the use of a nearly Isochronous Helical Transport Channel (IHTC) to facilitate capture of muons into RF bunches. Such a distribution could be cooled quickly and coalesced into a single bunch to optimize the luminosity of a muon collider. We describe the IHTC and provide simulations demonstrating isochronicity, even in the absence of RF and absorber.
Date: June 1, 2008
Creator: Yoshikawa, C.; Ankenbrandt, C.; Neuffer, D.; Popovic, M.; Yonehara, K.; /Fermilab et al.
Partner: UNT Libraries Government Documents Department