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Title: Fermilab recycler diagnostics


The Fermilab Recycler Ring is a permanent magnet storage ring for the storage and cooling of antiprotons. The following note describes the diagnostic tools currently available for commissioning, as well as the improvements and upgrades planned for the near future.

Publication Date:
Research Org.:
Fermi National Accelerator Lab., Batavia, IL (US)
Sponsoring Org.:
USDOE Office of Energy Research (ER) (US)
OSTI Identifier:
Report Number(s):
TRN: US0103770
DOE Contract Number:
Resource Type:
Resource Relation:
Conference: Particle Accelerator Conference 2001, Chicago, IL (US), 06/18/2001--06/22/2001; Other Information: PBD: 24 Jul 2001
Country of Publication:
United States

Citation Formats

Martin Hu. Fermilab recycler diagnostics. United States: N. p., 2001. Web.
Martin Hu. Fermilab recycler diagnostics. United States.
Martin Hu. 2001. "Fermilab recycler diagnostics". United States. doi:.
title = {Fermilab recycler diagnostics},
author = {Martin Hu},
abstractNote = {The Fermilab Recycler Ring is a permanent magnet storage ring for the storage and cooling of antiprotons. The following note describes the diagnostic tools currently available for commissioning, as well as the improvements and upgrades planned for the near future.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2001,
month = 7

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  • Fermilab has nearly completed an upgrade to its accelerator complex which is called the Fermilab Main Injector @MI). In addition to the FM1 ring itself, which is built of standard electromagnets, there are additional components. Two of these components, a beamline used for transporting 8 GeV protons from the existing Booster to the new FM1 ring, and a new storage ring for antiprotons, are made using permanent magnets. The storage ring has been named the Recycler because its function is to store leftover p-bars from the previous Tevatron Collider cycle after they have been decelerated to 8 GeV. Both themore » Recycler and the 8 GeV transfer line use magnets of similar technology. The magnetic material is strontium ferrite, chosen for reasons of economy and high H,. The temperature dependence of the ferrite is compensated by a Ni(30%)Fe(70%) alloy operating near its Curie temperature. Field quality is provided by steel pole pieces and custom shims. The Recycler Ring requires about 360 gradient magnets, 110 quadrupole magnets, and small numbers of Lambertson and special magnets. Nearly all of the magnets have been built. We present details of magnet design, manufacturing, and testing.« less
  • Design theory of hybrid (permanent magnet plus iron) accelerator magnets with application to the proposed permanent magnet recycler and stacker rings at the Fermi National Laboratory is presented. Field stability in such devices requires that changes in the strength of the permanent magnet material with temperature be compensated. Field tuning techniques, including those employing variable capacitance between energized pole and magnet yoke and those employing variable energization of magnet pole pieces, are described. Mechanical configurations capable of achieving temperature compensation passively, including use of expanding liquids/gases and bimetallic springs are outlined. Active configurations, relying on a actuator, in addition tomore » temperature compensation, have the additional benefit of enabling magnet tuning about a nominal operating field level.« less
  • Hybrid permanent magnets provide the magnetic fields for an anti- proton storage ring which is under construction at Fermilab. Using a combined function lattice, gradient magnets provide the bending, focusing and sextupole correction for the regular cells. Shorter magnets without sextupole are used in dispersion suppressor cells. These magnets use a 4.7 m ( 3 m) long iron shell for flux return, bricks of 25.4 mm thick strontium ferrite supply the flux and transversely tapered iron poles separated by aluminum spacers set the shape of the magnetic field. Central fields of 0.14 T with gradients of {approx}6%/inch ({approx}13%/inch) are required.more » Field errors are expected to be less than 10{sup -4} of the bend field over an aperture of {+-}40 mm (horizontal) {times} {+-}20 mm (vertical). Design, procurement, fabrication, pole potential adjustment, field shape trimming and measured fields will be reported.« less
  • Hybrid Permanent Magnet Quadrupoles are used in several applications for the Fermilab Recycler Ring and associated beam transfer lines. Most of these magnets use a 0.6096 m long iron shell and provide integrated gradients up to 1.4 T-m/m with an iron pole tip radius of 41.6 mm. A 58.4 mm pole radius design is also required. Bricks of 25. 4 mm thick strontium ferrite supply the flux to the back of the pole to produce the desired gradients (0.6 to 2.75 T/m). For temperature compensation, Ni-Fe alloy strips are interspersed between ferrite bricks to subtract flux in a temperature dependentmore » fashion. Adjustments of the permeance of each pole using iron between the pole and the flux return shell permits the matching of pole potentials. Magnetic potentials of the poles are adjusted to the desired value to achieve the prescribed strength and field uniformity based on rotating coil harmonic measurements. Procurement, fabrication, pole potential adjustment, and measured fields will be reported.« less