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Johnson, D. E.

Paper Title Page
MOPAS008 A Wide Aperture Quadrupole for the Fermilab Main Injector Synchrotron 455
 
  • D. J. Harding, C. L. Bartelson, B. C. Brown, J. A. Carson, W. Chou, J. DiMarco, H. D. Glass, D. E. Johnson, V. S. Kashikhin, I. Kourbanis, W. F. Robotham, M. Tartaglia
    Fermilab, Batavia, Illinois
  
  Funding: Work supported by the U. S. Department of Energy under Contract No. DE-AC02-76CH03000.

During the design of the Fermilab Main Injector synchrotron it was recognized that the aperture was limited at the beam transfer and extraction points by the combination of the Lambertson magnets and the reused Main Ring quadrupoles located between the Lambertsons. Increased intensity demands on the Main Injector from antiproton production for the collider program, slow spill to the meson fixed target program, and high intensity beam to the high energy neutrino program have led us to replace the aperture-limiting quadrupoles with newly built magnets that have the same physical length but a larger aperture. The magnets run on the main quadrupole bus, and must therefore have the same excitation profile as the magnets they replaced. We present here the design of the magnets, their magnetic performance, and the accelerator performance.

 
TUPAS010 Studies of Beam Properties and Main Injector Loss Control using Collimators in the Fermilab Booster to Main Injector Transfer Line 1670
 
  • B. C. Brown, P. Adamson, D. Capista, D. E. Johnson, I. Kourbanis, D. K. Morris, M.-J. Yang
    Fermilab, Batavia, Illinois
  
  Funding: Work supported by the U. S. Department of Energy under Contract No. DE-AC02-76CH03000.

High intensity operation of the Fermilab Main Injector has resulted in increased activation of machine components. Efforts to permit operation at high power include creation of collimation systems to localize losses away from locations which require maintenance. As a first step, a collimation system to remove halo from the incoming beam was installed in the Spring 2006 Facility Shutdown*. We report on commissioning studies and operational experience including observations of Booster beam properties, effects on Main Injector loss and activation, and operational results.

* B. C. Brown, et al., "Collimation System for the Fermilab Booster to Main Injector Transfer Line", this conference.

 
TUPAS012 Start-to-End Simulations for the Proposed Fermilab High Intensity Proton Source 1676
 
  • J.-P. Carneiro, D. E. Johnson
    Fermilab, Batavia, Illinois
  
  A High Intensity Proton Source consisting in an 8 GeV superconducting H-minus linac and transfer line to the Main Injector has been proposed. The primary mission is to increase the intensity of the Fermilab Main Injector for the production of neutrino superbeams. Start-to-end simulations from the RFQ to the stripping foil using the simulation code TRACK (ANL) will be presented in this paper. In particular, we will study the impact of errors (jitters and alignments) on the H- phase space at the entrance of the stripping foil.  
TUPAS016 Collimation System Design for Beam Loss Localization with Slipstacking Injection in the Fermilab Main Injector 1688
 
  • A. I. Drozhdin, B. C. Brown, D. E. Johnson, I. Kourbanis, N. V. Mokhov, I. Rakhno, V. Sidorov
    Fermilab, Batavia, Illinois
  • K. Koba
    KEK, Ibaraki
  
  Results of modeling with the STRUCT and MARS15 codes of beam loss localization and related radiation effects are presented for the slipstacking injection to the Fermilab Main Injector. Simulations of proton beam loss are done using multi-turn tracking with realistic accelerator apertures, nonlinear fields in the accelerator magnets and time function of the RF manipulations to explain the results of beam loss measurements. The collimation system consists of one primary and four secondary collimators. It intercepts a beam power of 1.6 kW at a total scraping rate of 5%, with a beam loss rate in the ring outside the collimation region of 1 W/m or less. Based on thorough energy deposition and radiation modeling, a corresponding collimator design was developed that satisfies all the radiation and engineering constraints.  
TUPAS018 A Conceptual Design of an Internal Injection Absorber of 8 GeV H- Injection into the Fermilab Main Injector 1694
 
  • D. E. Johnson, A. Z. Chen, I. Rakhno
    Fermilab, Batavia, Illinois
  
  Funding: Work supported by Universities Research Association, Inc. under contract No. DE-AC02-76CH03000 with the U. S. Dept. of Energy.

A 8 GeV H- superconducting linac has been proposed as an alternative injector for the Main Injector to support a 2 MW Neutrino program. An injection absorber is required to accept protons generated after the secondary stripping foil which will intercept the un-stripped H- and H0 particles after the MI primary foil injection point. The motivations underlying the choice of a compact internal absorber over an external absorber will be discussed. We show that using a high-Z material (tungsten) for the inner shielding allows the construction a compact absorber that can take a very intense beam and fits within the existing enclosure. The absorber requirements and a shielding design and the results of energy deposition calculations are presented.

 
TUPAS019 A Dynamic Dispersion Insert for the Fermilab Main Injector for Momentum Collimation 1697
 
  • D. E. Johnson
    Fermilab, Batavia, Illinois
  
  The Fermilab Main Injector accelerator is designed as a FODO lattice with zero dispersion straight sections. A scheme will be presented that can dynamically alter the dispersion of one of the long straight sections to create a non-zero dispersion straight section suitable for momentum collimation. During the process of slip stacking DC beam is generated which is lost during the first few milliseconds of the ramp. A stationary massive primary collimator/absorber with optional secondary masks could be utilized to isolate beam loss due to uncaptured beam.  
TUPAS020 An 8 GeV H- Multi-turn Injection System for the Fermilab Main Injector 1700
 
  • D. E. Johnson
    Fermilab, Batavia, Illinois
  • J. Beebe-Wang, C. J. Liaw, D. Raparia
    BNL, Upton, Long Island, New York
  
  Funding: Work supported by Universities Research Association, Inc. under contract No. DE-AC02-76CH03000 with the U. S. Dept. of Energy.

The technique for H- charge exchange for multi-turn injection utilizing stripping foils in the energy range of a few hundred MeV has been used at many labs for decades and most recently up to 1 GeV at the SNS. Utilization the beam from the proposed Proton Driver* would permit the extension of this technique up to 8 GeV. The injection layout and required accelerator modifications are discussed. Results from transverse and longitudinal simulations are presented.

* W. G. Foster and J. A. MacLachlan, "A Multi-mission 8 GeV Injector Linac as a Fermilab Booster Replacement", Proc. Of LINAC-2002, Gyeongju, Korea, p.86.

 
TUPAS038 The Concept Design of a New Transfer Line from Booster to Recycler for the Fermilab Proton Plan Phase 2 Campaign 1727
 
  • D. E. Johnson, M. Xiao
    Fermilab, Batavia, Illinois
  
  Funding: Work supported by URA under contract No. DEAC02-76CH03000 with the U. S.Dept. of Energy.

Upon the termination of the Fermilab Collider program, the current Recycler anti-proton storage ring will be converted to a proton pre-injector for the Main Injector 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.

 
TUPAS039 The Concept Design of a Transfer Line from the Recycler to the Main Injector for the Fermilab Nova Project 1730
 
  • M. Xiao, D. E. Johnson
    Fermilab, Batavia, Illinois
  
  Funding: Work supported by URA under contract No. DEAC02-76CH03000 with the U. S.Dept. of Energy.

Upon the termination of the Fermilab Collider program, the current Recycler anti-proton storage ring will be converted to a proton pre-injector for the Main Injector synchrotron. This is scheduled to increase the beam power for the 120 GeV Neutrino program to upwards of 700KW. Due to momentum aperture restriction, a new transport line that extracts the beam from the Recycler at a dispersion free region to the main injector will be discussed, and its concept design will be presented.

 
TUPAS015 Operational Aspects of the Main Injector Large Aperture Quadrupole 1685
 
  • W. Chou, C. L. Bartelson, B. C. Brown, D. Capista, J. L. Crisp, J. DiMarco, J. Fitzgerald, H. D. Glass, D. J. Harding, B. Hendricks, D. E. Johnson, V. S. Kashikhin, I. Kourbanis, W. F. Robotham, T. Sager, M. Tartaglia, L. Valerio, R. C. Webber, M. Wendt, D. Wolff, M.-J. Yang
    Fermilab, Batavia, Illinois
  
  Funding: Work supported by Universities Research Association, Inc. under contract No. DE-AC02-76CH03000 with the U. S. Dept. of Energy.

A two-year Large Aperture Quadrupole (WQB) Project was completed in the summer of 2006 at Fermilab.* Nine WQBs were designed, fabricated and bench-tested by the Technical Division. Seven of them were installed in the Main Injector and the other two for spares. They perform well. The aperture increase meets the design goal and the perturbation to the lattice is minimal. The machine acceptance in the injection and extraction regions is increased from 40π to 60π mm-mrad. This paper gives a brief report of the operation and performance of these magnets. Details can be found in Ref**.

* D. Harding et al, "A Wide Aperture Quadrupole for the Fermilab Main Injector," this conference.
** W. Chou, Fermilab Beams-doc-#2479, http://beamdocs.fnal.gov/AD-public/DocDB/DocumentDatabase