Channeling at Fermilab
History:
Channeling work at Fermilab started in 1974 with
the publication by
Dick Carrigan of "Possibility
of a Psi
Particle Beam Using Production Channeling" - Fermilab-FN‑0270
(see Phys.
Rev. Lett. 35, 206 (1975)). Originally the hope was that the
Angstrom feature size could be used to measure very short-lived
particle lifetimes. Soon the work shifted to
exploring the practical problems with channeling at multi-hundred GeV
(E-507). In the process, our collaborator, Edic
Tsyganov then of Dubna,
came up with the idea of bent
crystal channeling. That led to a low energy
demonstration at Dubna, use for extraction at Dubna and Serpukhov,
development of a theory of bent crystal channeling by our
collaborator, Jim
Ellison of the University of New Mexico, and extensive exploration
of that theory at Fermilab. The table on the right summarizes the
work in six major areas.
Hot Channeling Topics
Crystal collimation
This is now extremely interesting because of LHC requirements and channeling
fundamentals.
Volume reflection and capture
Relates to effects observed at PNPI, IHEP, CERN, RHIC and Fermilab that
may have
significant impact on channeling collimation.
Negative bending?
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A
team at Fermilab led by Nikolai Mokhov, Dean Still, and Vladimir
Shiltsev is now studying
this process as
an
advanced accelerator collimation technique in T-980.
[FERMILAB-CONF-09-173-APC
(2009)]
Using
channeling in E-853 a team led by Thornton Murphy and Gerry Jackson
extracted a 900 GeV beam from the
Fermilab
Tevatron. This was the highest energy beam ever extracted from an
accelerator. [Fermilab-pub-99-186-E.
Phys.Rev.ST Accel.Beams 5:043501 (2002)]
Teams led by Walter Gibson, Chih Ree Sun, and Jim Forster investigated
dechanneling, bent
crystal channeling, modulated nuclear interaction rates, crystal
properties, and other channeling effects in the Meson Lab at Fermilab
in experiments E-507, E-660, and E753.[Nuclear Physics B203,
40 (1982)].
Bent
crystal
channeling was used for a septum in the Fermilab Neutrino East area at
800
GeV. It has since been applied to secondary beams at Serpukhov and
CERN. [Fermilab-pub-86/20 Nucl.
Instr. Meth. A248 301 (1986)]
With
Harald Genz and Achim Richter we have used channeling radiation to
study the possibility for exotic
acceleration at the Fermilab International Linear Collider (ILC) A0
test
facility. [Phys.
Rev. A68:062901 (2003)]
At
a Fermilab Program Advisory Committee review of the E-660 channeling
proposal,
Lee Pondrum of the University of Wisconsin suggested
using bent crystals to measure short-lived particle magnetic moments.
(This
idea was proposed independently by Baryshevsky of Belarus.) With a
Leningrad team led by Vladimir Samsonov,
we demonstrated
that process with hyperons during E-761.[ Phys. Rev. Lett.
69, 3286 (1992).]
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