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Space-charge effects of the proposed high-intensity Fermilab booster

Description: Space-charge effects on beam stabilities are studied for the proposed two-ring high-intensity Fermilab booster destined for the muon collider. This includes microwave instabilities and rf potential-well distortions. For the first ring, ferrite insertion is suggested to cancel the space-charge distortion of the rf wave form. To control the inductance of the ferrite during ramping and to minimize resistive loss, perpendicular biasing to saturation is proposed.
Date: April 1, 1998
Creator: Ng, K.-Y. & Qian, Z.
Partner: UNT Libraries Government Documents Department

Survey data of Booster magnet misalignments

Description: As a part of the ongoing Booster improvement project, all the available data on booster magnets are collected and tabulated. Data include not only the survey results available at present (July 2003) but the magnet moves as well. The main purpose of this exercise is not to provide a basis for the future magnet moves. Rather, the goal is to present the present knowledge on where magnets are and incorporate it into, for example, the MAD lattice file so that one can see the impact of misaligned magnets on the closed orbit in the absence of any corrections.
Date: August 18, 2003
Creator: Ohnuma, Sho
Partner: UNT Libraries Government Documents Department

Fermilab Main Injector commissioning status

Description: The Fermilab Main Injector construction project is nearing completion. The commissioning of the Main Injector began in late 1998. The status of the beam studies and fulfillment of the project commissioning milestones is presented.
Date: April 8, 1999
Creator: Mishra, P.S. Martin and C.S.
Partner: UNT Libraries Government Documents Department

High intensity performance and upgrades at the Brookhaven AGS

Description: The high intensity proton beam of the AGS is used both for the slow-extracted-beam (SEB) area with many target station to produce secondary beams and the fast-extracted-beam (FEB) line used for the production of muons for the g-2 experiment and for high intensity target testing for the spallation neutron sources and muon production targets for the muon collider. The same FEB line will also be used for the transfer of beam to RHIC. The proton beam intensity in the AGS has increased steadily over the 35 year existence of the AGS, but the most dramatic increase occurred over the last couple of years with the addition of the new AGS Booster. All modifications associated with this are discussed.
Date: December 1, 1998
Creator: Roser, T.
Partner: UNT Libraries Government Documents Department

Measurement of {gamma}{sub T} with the {gamma}{sub T} quads on and off

Description: An experimental procedure for measuring {gamma}{sub T} has been developed and tested in two different measurements, with the {gamma}{sub T} quads on and off. The results were compared to MAD calculations. The discrepancy between the measured {gamma}{sub T} and the calculated {gamma}{sub T} is less than 5%.
Date: May 24, 2004
Creator: Xi Yang, James MacLachlan and Charles M. Ankenbrandt
Partner: UNT Libraries Government Documents Department

Beam-based determination of the offset of Booster {gamma}{sub T} quads

Description: Twelve pulsed {gamma}{sub T} quads have been installed in the Booster to provide fast transition crossing. The less time the beam stays in the non-adiabatic period near transition, the less the longitudinal emittance grows. From the past experience, the {gamma}{sub T} quads are not well aligned relative to the usual closed orbit. Quad steering can cause beam loss and a dispersion wave after transition. To make the {gamma}{sub T} quads routinely operational, procedures for finding the center of the beam relative to the quads and centering the beam through all of them are very important. A program, which uses the difference in the closed orbits when {gamma}{sub T} quads are on and off and calculates the offsets of the beam relative to {gamma}{sub T} quads, has been developed and tested. A radial orbit offset (ROF) of about 3 mm has been experimentally determined to be nearly the optimal radial position for centering the beam through all the {gamma}{sub T} quads, thereby eliminating the immediate need for repositioning the quads.
Date: June 23, 2004
Creator: Xi Yang, Charles M. Ankenbrandt and James MacLachlan
Partner: UNT Libraries Government Documents Department

Recycler ring conceptual design study

Description: The Tevatron Collider provides the highest center of mass energy collisions in the world. To fully exploit this unique tool, Fermilab is committed to a program of accelerator upgrades for the purpose of increasing the Collider luminosity. Over the past 7 years the luminosity has been increased from a peak of 1.6{times}10{sup 30}cm{sup {minus}2}sec{sup {minus}1} in 1989 to over 3{times}10{sup 31}cm{sup {minus}2}sec{sup {minus}1} during 1995. The Main Injector will supply a larger flux of protons for antiproton production and more intense proton bunches for use in the Collider, and this is expected to increase the peak luminosity to close to 1{times}10{sup 32}cm{sup {minus}2}sec{sup {minus}1}. Further increases in luminosity will require additional upgrades to the Fermilab accelerator complex. This report documents the design of a new fixed-energy storage ring to be placed in the Main Injector tunnel which will provide an initial factor of 2 increase to 2{times}10{sup 32}cm{sup {minus}2}sec{sup {minus}1}, and ultimately provide the basis for an additional order of magnitude luminosity increase up to 1{times}10{sup 33}cm{sup {minus}2}sec{sup {minus}1}.
Date: July 18, 1995
Creator: Jackson, G.
Partner: UNT Libraries Government Documents Department

Beam loading effects in the APS booster

Description: Beam loading of the radio-frequency (rf) accelerating cavities is an important consideration in the design and operation of high-current circular particle accelerators and storage rings. The steady-state and transient perturbations of the rf cavity system by the circulating beam can be harmful to the beam and limit the accelerator performance. Transient beam loading effects have been observed soon after injection of the beam into the booster synchrotron of the Advanced Photon Source (APS). Data are presented quantifying the responses of both the beam and the rf cavities to beam loading under various conditions. A preliminary discussion addresses the compensation of these beam loading effects. 3 refs., 3 figs., 1 tab.
Date: June 1, 1996
Creator: Harkay, K.; Lumpkin, A.; Milton, S.; Nassiri, A.; Song, J. & Yang, B.
Partner: UNT Libraries Government Documents Department

Characterization of beam dynamics in the APS injector rings using time-resolved imaging techniques

Description: Images taken with streak cameras and gated intensified cameras with both time (longitudinal) and spatial (transverse) resolution reveal a wealth of information about circular accelerators. The authors illustrate a novel technique by a sequence of dual-sweep streak camera images taken at a high dispersion location in the booster synchrotron, where the horizontal coordinate is strongly correlated with the particle energy and the {open_quotes}top-view{close_quotes} of the beam gives a good approximation to the particle density distribution in the longitudinal phase space. A sequence of top-view images taken fight after injection clearly shows the beam dynamics in the phase space. We report another example from the positron accumulator ring for the characterization of its beam compression bunching with the 12th harmonic rf.
Date: June 1, 1997
Creator: Yang, B.X.; Lumpkin, A.H. & Borland, M.
Partner: UNT Libraries Government Documents Department

AGS performance and upgrades; A possible proton driver for a muon collider

Description: After the successful completion of the AGS Booster and several upgrades of the AGS, a new intensity record of 6.3 x 10{sup 13} protons per pulse accelerated to 24GeV was achieved. Further intensity upgrades are being discussed that could increase the average delivered beam intensity by up to a factor of six. The total beam power then reaches almost 1 MW and the AGS can then be considered as a proton driver for a muon collider.
Date: December 31, 1995
Creator: Roser, T.
Partner: UNT Libraries Government Documents Department

A multi-wire beam profile monitor in the AGS

Description: A multi-wire beam profile monitor which can be used to directly monitor and control the optical matching between the Booster and AGS rings has been installed and tested in the AGS. Placement of a multi-wire monitor directly in the AGS provides profile measurements taken upon injection and the first two or more revolutions of the beam. The data from such measurements can be used to determine the optical properties of the beam transport line leading into the AGS.
Date: July 1, 1997
Creator: Huang, H.; Buxton, W.; Castillo, V. & Glenn, J.W.
Partner: UNT Libraries Government Documents Department

Anomolous, intensity dependent losses in Au(32+) beams

Description: The AGS Booster is a rapid cycling proton and heavy ion synchrotron. Anomolous, intensity dependent losses in Au(32+) beams have been observed in the AGS Booster. No collective signal is expected, or observed, but increasing the number of injected ions decreases the beam lifetime. The loss rates for Au(32+) are compared with those for Au(15+).
Date: July 1, 1997
Creator: Blaskiewicz, M.; Ahrens, L. & Calvani, H.
Partner: UNT Libraries Government Documents Department

Automated tuning of the advanced photon source booster synchrotron

Description: The acceleration cycle of the Advanced Photon Source (APS) booster synchrotron is completed within 223 ms and is repeated at 2 Hz. Unless properly corrected, transverse and longitudinal injection errors can lead to inefficient booster performance. In order to simplify daily operation, automated tuning methods have been developed. Through the use of beam position monitor (BPM) reading, transfer line corrector magnets, magnet ramp timing, and empirically determined response functions, the injection process is optimized by correcting the first turn trajectory to the measured closed orbit. These tuning algorithms and their implementation are described here along with an evaluation of their performance.
Date: August 1, 1997
Creator: Biedron, S.G. & Milton, S.V.
Partner: UNT Libraries Government Documents Department

An overview of the APS 352-MHz rf systems

Description: The Advanced Photon Source (APS) is a 7-GeV full energy positron storage ring for generating synchrotron radiation with an injector. The booster synchrotron rf system consists o a single 1-MW klystron which drives four five-cell cavities at 352 MHz. The storage ring cavities consist of four groups of four single cells powered by two 1-MW klystrons for 100-mA operation. An overview of the operation of the APS 352-MHz rf systems is presented.
Date: August 1, 1997
Creator: Nassiri, A.; Cours, A.; Grelick, A.; Horan, D.; Kang, Y.W.; Kustom, R.L. et al.
Partner: UNT Libraries Government Documents Department

Tune control in the Fermilab Main Injector

Description: We describe methods used to measure and control tunes in the Fermilab Main Injector (FMI). Emphasis is given to software implementation of the operator interface, to the front-end embedded computer system, and handling of hysteresis of main dipole and quadrupole magnets. Techniques are developed to permit control of tune of the Main Injector through several acceleration cycles: from 8.9 GeV/c to 120 GeV/c, from 8.9 GeV/c to 150 GeV/c, and from 150 GeV/c to 8.9 GeV/c. Systems which automate the complex interactions between tune measurement and the variety of ramping options are described. Some results of tune measurements and their comparison with the design model are presented.
Date: April 16, 1999
Creator: Wu, G.; Brown, B. C.; Capista, D. P.; Flora, R. H.; Johnson, D. E. & Martin, K. S.
Partner: UNT Libraries Government Documents Department

Niobium quarter-wave cavity for the New Delhi booster linac

Description: This paper reports the completion of development of a 97 Mhz niobium coaxial quarter-wave cavity to be used in a booster linac for the New Delhi 16UD pellatron electrostatic accelerator. A prototype cavity, which incorporates a niobium-bellows tuning device, has been completed and operated at 4.2 K at accelerating gradients above 4 MV/m for extended periods of time.
Date: September 1, 1997
Creator: Shepard, K.W.; Roy, A. & Potukuchi, P.N.
Partner: UNT Libraries Government Documents Department

Design of the NLC positron source

Description: The design of the positron source for the Next Linear Collider (NLC) is presented. The key features of this design include accelerating positrons at an L-band frequency (1428 MHz) and using a rotating positron target with multi-stage differential pumping. Positron yield simulations show that the L-band design yields at the source 2.5 times the beam intensity required at the interaction point and is easily upgrade to higher intensities required for the 1 TeV NLC upgrade. Multi-bunch beam loading compensation schemes in the positron capture and booster accelerators and the optics design of the positron booster accelerator are described. For improved source efficiency, the design boasts two parallel positron vaults adequately shielded from each other such that one serves as an on-line spare.
Date: August 1, 1996
Creator: Tang, H.; Emma, P.; Gross, G.; Kulikov, A.; Li, Z.; Miller, R. et al.
Partner: UNT Libraries Government Documents Department

Strength and shape of the magnetic field of the Fermilab Main Injector dipoles

Description: Measurements of 230 6-meter and 136 4-meter dipoles constructed for the Fermilab Main Injector were carried out as part of the magnet production effort. An automated measurement system provided data on magnetic field strength and shape using several partially redundant systems. Results of these measurements are available for each individual magnet for use in accelerator modelling. In this report we will summarise the results on all of the magnets to characterise the properties which will govern accelerator operation.
Date: April 8, 1999
Creator: al., D.J. Harding et
Partner: UNT Libraries Government Documents Department

Unexpected matching insensitivity in DTL of GTA accelerator

Description: The Intertank Matching Section (IMS) of the Ground Test Accelerator (GTA) contains four variable-field quadrupoles (VFQs) and is designed to match beam exiting the Radio-Frequency Quadrupole to the first tank of the Drift-tube LINAC (DTL-1). By varying the VFQ field strengths to create a range of beam mismatches at the entrance to DTL-1, one can test the sensitivity of the DTL-1 output beam to variations in the DTL-1 input beam. Experimental studies made during commissioning of the GTA indicate an unexpected result: the beam exiting DTL-1 shows little variation for a range of mismatches produced at the entrance. Results of the experiment and simulation studies are presented.
Date: May 1995
Creator: Yuan, V. W.; Gilpatrick, J. D.; Johnson, K. F.; Lysenko, W. P.; Rusthoi, D. P.; Sander, O. R. et al.
Partner: UNT Libraries Government Documents Department

Hysteresis study techniques and results for accelerator magnets with unipolar current excitation

Description: Using an automated magnet measurement system employing a variety of current excitation ramps, extensive studies of the hysteretic behavior of magnet strength have been carried out. An analytic description which is accurate at better than 0.1% has been achieved. Prescriptions for setting field strength using these formulas will be adequate for multi-energy operation of the Fermilab Main Injector, for deceleration in the Main Injector and Accumulator and for multi-energy operation of various beamline magnets. An overview of this work is provided. Important regularities of the magnet behavior are identified.
Date: April 23, 1999
Creator: Brown, Bruce C.
Partner: UNT Libraries Government Documents Department

Four quadrant 250KW switchmode power supply for Fermilab Main Injector

Description: A +/-700 volt,+/-350 amp switchmode power supply has been developed for Fermilab Main Injector Sextupole Correction System. The four quadrant operation is accomplished by using four IGBTs in an H-bridge configuration with a switching frequency of 10 KHz. Current regulation bandwidth of 300 Hz is achieved with stability better than 250 ppm of rated current by using a high precision current transducer. The H-bridge outputs are filtered resulting in a maximum output voltage ripple of 2.5 volts peak to peak. The power supply has power conversion efficiency better than 80% and works at near unity power factor throughout its operation. The critical considerations involved in this power supply are low inductance bus plate and snubber design, selection and thermal management of IGBTs, IGBT gate drive, PWM output filtering, and fiber optic controls. The paper will discuss the design and performance of the power supply.
Date: April 8, 1999
Creator: Si Fang, George Krafczyk, Howie Pfeffer and Dan Wolff
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

A study of the HEB longitudinal dynamics

Description: A study of the High Energy Booster (HEB) longitudinal dynamics is presented. Full derivations of ramp dependent longitudinal variables are given. The formulas assume that the input magnetic field and beam longitudinal emittance are known as a function of time, and that either the rf voltage or the rf bucket area are known as a function of time. Once these three inputs are specified, the formulas can be used to calculate values for all other longitudinal dynamics variables. The formulas have been incorporated into a single computer code named ELVIRA: Evaluation of Longitudinal Variables in Relativistic Accelerators. The ELVIRA code is documented here in detail. The ELVIRA code is used under two initial longitudinal emittance assumptions to plot ramp functions for the longitudinal dynamics design of the HEB as of May 5, 1992.
Date: December 1, 1993
Creator: Larson, D.J.
Partner: UNT Libraries Government Documents Department

Status of the Proton Driver Study at Fermilab

Description: In order to enhance Fermilab hadron research program and to provide a proton source to a future muon storage ring or a muon collider, the study of a new high intensity proton ma-chine called the Proton Driver is being pursued at Fermilab. It would replace the present linac and 8 GeV Booster and produce 20 times the proton intensity as the Booster. This paper gives a status report on a number of design issues of this machine.
Date: May 17, 1999
Creator: Chou, Weiren
Partner: UNT Libraries Government Documents Department