[Task Description]{.underline}

The Neutrino Factory and Muon Collider Collaboration (*MC)* comprises
three sponsoring national laboratories (BNL, FNAL, LBNL) along with
groups from other U.S. national laboratories and universities and
individual members from non-U.S. institutions. Its task is to define and
carry out R&D required to assess the technical feasibility of
constructing initially a muon storage ring that will provide intense
neutrino beams aimed at detectors located many thousands of kilometers
from the accelerator site, and ultimately a *μ*+*μ*-- collider that will
carry out fundamental experiments on the energy frontier in high-energy
physics. The *MC* stays in close contact with parallel efforts under way
in Europe (centered at CERN) and in Japan (centered at KEK). The
Collaboration is also the focal point for defining the needs of
muon-related R&D to the management of the sponsoring national
laboratories and to the funding agencies (both DOE and NSF). Through its
international members, the *MC* also fosters coordination of the
international muon-beam R&D effort. Two major initiatives, a Targetry
Experiment (E951) recently approved for operation at BNL and a Muon
Cooling R&D program (MUCOOL), have been launched by the *MC*. In
addition, the Collaboration coordinates substantial efforts in
accelerator physics and component R&D to define and assess parameters
for feasible designs of such facilities.

[Purpose]{.underline}

Successful construction of a muon storage ring to provide a copious
source of neutrinos requires many novel approaches to be developed and
demonstrated. To construct a high-luminosity muon collider is an even
greater extrapolation of the present state of accelerator design. The
breadth of R&D issues to be dealt with is beyond the resources available
at any single national laboratory or university. For this reason, the
interested members of the high-energy physics and accelerator physics
communities have formed the *MC* to coordinate the required R&D efforts
nationally. The Collaboration elects a Spokesperson (now Andrew Sessler
from LBNL) to be contact person for policy and planning with the funding
agencies, with the management of the sponsoring national laboratories
and universities, and with the Muon Collider Oversight Group (MCOG) and
its Technical Advisory Committee (MUTAC). A Project Manager (now Michael
Zisman from LBNL), appointed by MCOG, is responsible for overseeing the
implementation of the *MC* R&D program and for reporting on the budget,
schedule, and technical progress to MCOG and to the DOE. The
Collaboration, through its Executive Committee and Technical Committee,
reviews and approves funding for muon-related R&D activities. The
Project Manager, in consultation with the *MC* Spokesperson, advises the
sponsoring national laboratories about how best to use their
muon-related "base program" resources in a complementary manner.

[Approach]{.underline}

To coordinate the R&D program, the *MC* holds semiannual Collaboration
Meetings where summaries of ongoing work are presented and proposals and
plans for new activities are made. The Project Manager, with the help of
the Collaboration Spokesperson, is responsible for preparing budget
submissions to the DOE, and accounting for monies previously allocated.
*MC* R&D plans and progress are reviewed on a regular basis by MUTAC,
made up from experts in the field. MUTAC members are appointed by, and
report to, MCOG, which presently includes senior managers from the three
sponsoring national laboratories. MCOG provides oversight for the
Collaboration and, together with the Project Manager, represents the
Laboratory viewpoint to the funding agencies.

Each year, R&D plans will be submitted to and reviewed by the *MC*
Technical Committee. Budgets will be prepared by the R&D leaders and
reviewed prior to allocation of *MC* resources, and a schedule with
auditable milestones will be required. Prior to committing major funds
for component fabrication or consulting activities, there will be a
Final Design Review organized by the Project Manager to validate the
expenditure. The Project Manager will subsequently be responsible for
monitoring and reporting progress to the *MC*, MCOG, and the funding
agencies.

A neutrino factory comprises the following major systems: Proton Driver,
Target and (Pion) Capture Section, (Pion-to-Muon) Decay and Phase
Rotation Section, Bunching and Matching Section, Cooling Section,
Acceleration Section, and Storage Ring. These same categories remain for
a muon collider, with the exception that the Storage Ring is replaced by
a Collider Ring having a low-beta interaction point and a local
detector. Parameters and requirements for these systems are generally
more severe in the case of the muon collider, so a neutrino factory can
properly be viewed as a scientifically productive first step toward the
eventual goal of a muon collider. With this in mind, the Collaboration
is concentrating most of its initial effort on the R&D activities that
will lead to a design for a neutrino factory. Longer-term activities
related primarily to the muon collider are also supported and
encouraged.

Each of the major systems has significant issues that must be addressed
by R&D activities, including a mix of theoretical, simulation, modeling,
and experimental studies, as appropriate. A brief summary of the key
physics and technology issues for each major system is given below.

Proton Driver:

• Production of intense, short proton bunches, e.g., with space-charge
compensation and/or high-gradient, low frequency RF systems

Target and Capture Section:

• Power dissipation in the target and beam dump (up to 4 MW of incident
protons)

• Performance and pion yield of a liquid-metal jet target

• Performance and pion yield of a solid target

• Verification of predicted pion yield in the Capture Section

• Optimization of target material and geometry (low-*Z* or high-*Z*) by
determination of production curves (number of particles vs. energy) for
various choices

• Design and performance of a high-field solenoid (≈20 T) in a very high
radiation environment

• Development of remote handling capability for target and capture
system components

Decay and Phase Rotation Section:

• Design, and performance in a high-radiation environment, of
high-gradient, low-frequency RF systems used in conjunction with an
external or internal solenoid channel

• Development of efficient and cost-effective high-power sources (e.g.,
klystrons, tetrodes) for low-frequency RF systems

• Design and performance of high-gradient induction linac modules having
an internal superconducting solenoid channel

• Identification and assessment of techniques for polarization
preservation

Bunching and Matching Section

• Design and development of efficient bunching system

• Design of transverse matching optics into downstream cooling section

Cooling Section

• Design of transverse emittance cooling channel to reduce emittance by
up to a factor of 10 in each plane

• Design and performance of high-gradient RF cavities at a frequency
near 200 MHz

• Design and performance of efficient high-power sources at a frequency
near 200 MHz

• Design of absorbers (e.g., liquid hydrogen or LiH) for muon cooling

• Design of large-aperture high-field solenoids compatible with 201-MHz
RF cavities

• Design of diagnostics to measure emittance and optimize cooling
channel performance

• Verification of multiple scattering and energy straggling predictions

• Demonstration of transverse emittance cooling (MUCOOL program)

• Design and demonstration of diagnostics needed for MUCOOL program

• Design of longitudinal emittance cooling channel ("emittance
exchange")

Acceleration Section

• Design and performance of high-gradient linac at a frequency near 200
MHz (both normal conducting and superconducting versions are needed)

• Design of rapid and efficient acceleration techniques to increase the
energy of a muon beam (with a large momentum spread) from a few GeV to a
few tens of GeV (e.g., recirculating linacs, rapid cycling synchrotrons,
fixed-field, alternating gradient rings) for a neutrino factory, or even
higher for a muon collider

• Design of accelerator lattices to accommodate a muon beam with large
momentum spread

• Development of high-gradient superconducting RF cavities at
frequencies near 200 MHz, along with efficient power sources (about 10
MW peak) to drive them

• Design and testing of components (RF cavities, magnets, diagnostics)
that will operate in the muon-decay radiation environment

Storage Ring

• Design of a storage ring with long straight sections aimed at suitable
detectors far from the accelerator site

• Design of large aperture, well shielded superconducting magnets that
will operate in the muon-decay radiation environment

• Design of superconducting RF cavities that will operate in the
muon-decay radiation environment

Collider

• Cooling of 6-D emittance (*x, px y, py, t, E*) by up to a factor of
105--106

• Acceleration systems to reach an eventual muon beam energy of about 2
TeV

• Design of a collider ring with very low beta (a few mm) at the
interaction point having sufficient dynamic aperture to maintain
luminosity for about 1000 turns

• Study of muon beam dynamics at high beam-beam tune shifts

• Study of longitudinal space-charge phenomena

Detector

• Simulation studies to define acceptable approaches for both near and
far detectors at a neutrino factory and for a collider detector
operating in a high-background environment

• Develop ability to detect electrons in detector environment

Future Accomplishments

Fiscal Year 2000

During this year, simulations of an initial version of the Front End of
a Neutrino Factory will be completed. The Front End simulations will
follow the muons from their production (via pion decay) downstream of
the target to the end of an example cooling channel comprising solenoid
focusing, high-gradient RF cavities (*f* ≈ 200 MHz), and absorbers of
liquid hydrogen. Work on understanding and optimizing the Front-End
design will continue throughout the year. Investigations of error
sensitivity will commence. Additional simulations will be carried out to
help define the MUCOOL demonstration. A three-week workshop focusing on
emittance exchange will be held at BNL toward the end of the year.
Understanding this topic is critical for an eventual muon collider and
even now offers promise to mitigate the effects of the large beam energy
spread in the neutrino factory cooling channel.

Work will continue on the targetry experiment, recently approved for
operation at BNL. This year the primary emphasis will be on getting the
A3 beam line at BNL ready for beam. Other effort will include
refurbishing a 70-MHz RF power source at LBNL. This unit will be sent to
BNL where it will power a 70 MHz RF cavity having a solenoid field, to
be tested ultimately as part of the initial phase rotation channel (for
polarization preservation). In addition to getting ready for
experimental tests with the refurbished equipment, engineering studies
of a 20-T pulsed solenoid magnet will begin. These will start to explore
the hardware implications of operating a high-field solenoid magnet in a
high-radiation area. Parallel studies will be carried out on the
development of a 5 MW power supply for the pulsed magnet. Simulation
studies of solid and liquid-metal targets will be continued to define an
initial configuration to test.

Preparations for a muon cooling demonstration (as part of the MUCOOL
effort) will continue. Work this year will focus on defining a
time-phased set of experimental goals and on developing and testing the
required hardware. To focus on the parameter regime appropriate for a
Neutrino Factory, the Collaboration will begin to concentrate mainly on
the initial portion of the cooling channel where the incoming beam
emittance is very large. Carrying out such experiments will require a
muon beam line somewhere in the world. Identifying a site for this beam
line will be an important goal, as the facility is clearly a long lead
time item. To prepare for the experimental program, the first step is to
develop components to test. For historical reasons, our initial
components will operate at 805 MHz, so they serve as scale models of the
actual components. Work is under way to prepare a facility at FNAL (Lab
G) for cooling experiment component tests (without beam). This includes
installation of refrigeration and power supplies for superconducting
solenoids, and power supplies for a high-power 805-MHz open-cell test
cavity being completed at FNAL. A 5-T solenoid that can operate in
either a standard solenoid or a gradient-solenoid mode (with two coils
of opposite polarity) will be completed at LBNL and shipped to FNAL for
the tests in Lab G. Initial work will aim at issues associated with
operating a high-gradient RF cavity in a strong solenoidal magnetic
field. Fabrication of a high-power 805-MHz cavity having beryllium
windows will also begin this year. Complementary studies at LBNL will
address the behavior of liquid-nitrogen-temperature 5-mil (125-*μ*m)
beryllium windows under low-power RF heating to look for deformation
effects and define a suitable operating regime. Work is under way at
University of Mississippi, Princeton University, UCLA, and elsewhere to
investigate suitable diagnostics devices for the experiments, including
Cerenkov detectors, fast-timing devices, TPCs and the like. Work is also
proceeding at ANL to examine the x-ray flux from high-gradient RF
cavities to evaluate this potentially significant source of backgrounds
for a cooling demonstration experiment. Absorber cell development work
will focus on development of strong, thin, low-*Z* containment windows.
Safety verification of the design will be an important initial task. A
test area, probably at FNAL, will be developed for this work, which will
be led by the Illinois Institute of Technology and Northern Illinois
University.

Design work on a 201-MHz high-power normal conducting (NC) RF cavity
will begin, as will design of a solenoid magnet to fit around it. After
fabrication, these devices will be tested, first in Lab G and ultimately
with a muon beam. As a follow-up to the first Feasibility Study (see
below), design work will begin at Cornell (funded by NSF) for
low-frequency superconducting RF cavities. There are a number of
technical issues to be addressed in the development of high gradient
SCRF cavities at frequencies as low as 200 MHz. The niobium sputtering
process must be well controlled over a large surface area, the
mechanical structure must be free of low-frequency resonances, and the
cavity shell manufacturing process must be efficient and reliable for
cost reasons. Initial design work will focus on a single-cell cavity
with input coupler port. ANSYS calculations will be done to determine
the parameters (shape and wall thickness) necessary to ensure that
mechanical resonances will be pushed to high frequencies. Alternative
cavity fabrication techniques will also be studied. One approach will
use a copper cavity spun as two half-cells and electron-beam welded,
then sputtered with niobium, as was done for CERN cavities. A second
approach will aim at a single-piece spinning from one sheet or perhaps a
tube, thus avoiding the welding process. This will involve collaboration
with INFN in Italy and industry. The goal of this effort is to
understand and improve the performance of SCRF cavities in this
frequency regime to reach the required operating parameters.

The Collaboration is also working with FNAL staff in carrying out a
Feasibility Study for an entry-level Neutrino Factory. This study will
serve to flesh out many of the possible design options and will identify
potential cost drivers of such a facility. From this study will come the
next round of design alternatives and some of the directions that the
R&D program will need to take to aim for a proposal to construct such a
facility at some future date. A second study of this type, focusing on a
"high-end" facility, carried out jointly by BNL and the Collaboration,
will commence toward the end of the year.

Fiscal Year 2001

Simulation studies this year will emphasize further optimization of the
front-end design. Analytic work that aids in understanding better the
key design principles will also be done. Both efforts will feed into the
second feasibility study, which will be completed during this year.
Hardware constraints and limitations defined by the component R&D
efforts will be incorporated into the simulations as they become
available, in order to ensure that the design uses practically
realizable components. Estimates will be made of polarization, to assess
whether an initial phase rotation is able to significantly enhance the
beam polarization and/or the *μ*/p (muon per incident proton) ratio
delivered to the downstream acceleration section. Studies of emittance
exchange techniques will continue, following up ideas generated at the
Emittance Exchange Workshop. This year, the Front End simulation study
will be extended to include the downstream portions of a Neutrino
Factory---the acceleration chain and the storage ring itself. When
completed, these extended simulation efforts will define a strawman
design for a complete facility. Simulation studies for the specific
parameters of a possible MUCOOL demonstration will also continue.
Finally, simulations this year will focus more heavily on the downstream
portions of the facility, the acceleration chain and the storage ring,
paying particular attention to the "transition region" where the
focusing changes from solenoidal to quadrupole. This will include
detailed modeling of the accelerator magnets including multipole and
strength errors and fringe field effects, using tools such as COSY.
During this year the results of the feasibility studies and the R&D
program will be summarized for the HEP community as part of the
preparations for the anticipated Snowmass '01 meeting that will serve to
define future directions for HEP nationally and perhaps internationally.

The targetry experiment A3 line at BNL will see first beam this year.
After commissioning, it is expected that initial target tests will take
about 6 weeks of (parasitic) beam time. Tests of a liquid-metal jet
target in a high magnetic field will get under way at the National High
Magnetic Field Laboratory in Florida. This work is a precursor to actual
beam tests at BNL. Initial work on solid target R&D will also begin this
year. Target geometries and cooling will be examined via simulations to
evaluate steady-state and peak thermal stresses, the latter being
important in the context of fatigue failure. The primary short-term goal
is to determine the survivability of a passively cooled graphite target
under the thermal and radiation conditions expected at a Neutrino
Factory. This will involve the following activities: *i*) evaluation of
the properties of different grades of graphite, including carbon-carbon
composites; *ii*) thermal tests to determine bending-creep and
axial-creep effects on full-scale target rods for various support
schemes; *iii*) investigation of non-uniform power distribution on
full-scale rods to determine temperature and stress effects; *iv*)
thermal shock tests on small scale samples; *v*) neutron irradiation
tests to determine target survivability; *vi*) designing and testing of
one or more water cooling schemes for the target support tube. Other
activities will include investigation (by calculation and tests) of the
impact of pressure shock-wave effects due to the very short duration
beam spill, development of a design for a water-cooled graphite target
if tests on the passively cooled target are unsuccessful (i.e.,
fabricate small-scale samples of graphite with cooling tubes and test
them for thermal and radiation survivability), and evaluation of safety
and environmental requirements and assessment of their impact on the
target system design and operation. To provide a suitable test beam from
the AGS, work will begin to upgrade the extraction kicker system. This
year will see the beginning of fabrication of a 20-T test solenoid, its
5-MW pulsed power supply, and a test target for the A3 line. Diagnostics
for studying the pion yield from the target will be fabricated. Results
from the HARP experiment at CERN will be folded into our design and
simulation effort as they become available; we will monitor the progress
of this experiment and provide support if needed. Tests on radiation
hardness of materials for the target station and its solenoid magnet
will begin, with the ultimate goal of defining suitable materials and
fabrication techniques for these components. This year's work will focus
on structural tests of candidate materials to ensure suitable mechanical
properties for magnet fabrication. This work, by MSU staff, will be
supported by NSF.

Systems issues related to safe handling of the irradiated targets in the
final facility will begin this year. Over the next several years, we
will develop full-scale mock-ups (using simulated components and
substitute materials where possible) to demonstrate remote handling of
key components. A partial mock up of the target region, complete with
utility interfaces (electrical, cooling, instrumentation) will be
fabricated. This setup will be used to demonstrate replacement of the
target module, replacement of the Bitter coil, and replacement of the
proton beam window. Finally, consequences of possible failure modes,
e.g., of the beam isolation window, will be investigated to make sure
the design is robust against such occurrences. We expect to benefit in
this area from close collaboration with groups at existing facilities
(or those now under construction) that have similar requirements for
beam power on target.

Fabrication of components suitable for a cooling channel will begin this
year. Design of a 201-MHz high-power NCRF cavity will be completed. R&D
on the corresponding superconducting solenoid will begin this year. This
may involve scale models initially to explore the parameter regime of
interest quickly. Achieving the required solenoid field strength on axis
is reasonably straightforward technically, but will require substantial
R&D to achieve it at reasonable cost. Moreover, achieving the exact
field shape considering engineering constraints on current densities, on
field on the coils, and on forces on the coils and supports, generally
requires a number of iterations. Each coil configuration studied should
have a maximum field on the coil below about 9 T. Common rules on the
allowable hoop stress will be developed by the experts, to provide
guidance to the simulation and design groups on what configurations are
acceptable. Mechanical stability analysis for the magnets of the cooling
channel, development of a mechanical scheme for the channel, and design
of a mechanical support for coils and magnets in the cooling channel
will be carried out. The design will be optimized to reduce the
mechanical stress on the coil. Detailed analysis of quench behavior,
including the mechanical stresses induced on the magnet coils, is also
important. Another issue to evaluate is that of field quality. Based on
engineering estimates of coil placement accuracy, we will assess the
effects on the beam cooling and transport of the field imperfections
that result from coil displacements and from edge-field effects. A
prototype absorber will be fabricated. After completing safety tests, it
will ultimately be tested in a proton or electron beam to verify its
thermal design.

Studies of muon-beam instrumentation will commence at Northwestern
University and University of Chicago this year, supported by NSF.
Although measurements of muon beams have been done for years, the issues
associated with the cooling channel will make the required measurements
difficult. Measurement requirements include: *i*) initial matching of
the cooling optics to the beam parameters, *ii*) maintaining this match
down the length of the cooling channel, *iii*) producing and maintaining
the physical alignment of beam components, *iv*) identifying and
minimizing transverse and longitudinal loss mechanisms, and *v*)
measurement of the emittance at various stages of cooling. Ideally, we
wish to have high-precision measurements of the six-dimensional muon
phase space at a variety of locations along the cooling channel and
acceleration system, although the only experimentally available
quantities are the transverse and longitudinal bunch profiles.
Measurement of the muon emittance from a beam profile is complicated by
possible mismatches in the cooling optics that could produce errors in
the beta function and the calculated emittance. Measurements could also
be complicated by pion and other backgrounds, particularly at the
upstream end of the cooling channel. While many conventional accelerator
diagnostics may be appropriate for some applications, it seems desirable
to look carefully at secondary emission monitors (SEMs) and Faraday
cups. The intense muon beams expected would produce large signals
without amplification, and the short range of low-energy muons would
permit the option of stopping the beam in a transmission line and
looking at the electrical pulse directly.

Proton driver R&D will get under way this year. Included will be studies
of the microwave instability below transition, prototyping and testing
of high-gradient RF structures, and the design of inductive inserts for
space-charge compensation. Such inserts will later be tested with beams
at FNAL, BNL, and/or LANL. Studies and development of techniques for
high-intensity bunch compression will begin. Much of this work is
motivated and supported by other interests, so the benefits to the *MC*
are highly leveraged in this case.

Investigations on suitable high-efficiency and high-power RF sources
will be done. An engineering design for an induction linac module,
including an internal superconducting solenoid, will be made in
preparation for fabricating a complete prototype cell. Fabrication of a
201-MHz SCRF cavity will be completed this year and processing will
begin at Cornell.

Fiscal Year 2002

For the targetry experiment, fabrication of a pulsed 20-T solenoid and
its 5-MW power supply will be completed. A selected target will be
tested with beam this year, with the choice based on the studies carried
out the previous year. An upgrade of the AGS extraction kicker to permit
fast extraction of the entire beam will be done. Fabrication of a
high-power, 70-MHz RF cavity will continue in preparation for beam
testing, as will fabrication of instrumentation for pion detection. Late
in the year, pion yield measurements will begin, to verify the MARS
predictions on which the Neutrino Factory design is being based.
Simulations in support of this measurement effort will continue.
Radiation tests on selected coil materials will begin this year, to
verify behavior prior to actual magnet fabrication. As part of this
work, we will launch an effort to measure neutron yields from the
target, to compare with predictions of the MARS code. Systems studies of
the target facility will continue to identify and test key issues
related to handling and remote maintenance.

Fabrication of all cooling channel components required for the initial
phase of testing, including a high-power 201 MHz NCRF cavity, a test
solenoid, and diagnostics that will be used for the experiment, will be
completed. Simulation efforts in support of a cooling demonstration
program will continue. Plans for beam testing will be finalized. Thermal
tests of the absorber with a suitable electron or proton beam will
commence.

Proton driver R&D this year will involve beam tests to produce the short
bunches and high intensities needed for a Neutrino Factory. A test of
inductive inserts to compensate for space-charge effects will be carried
out at FNAL and/or BNL.

A prototype induction linac cell, operating at 2 MV/m and including an
internal superconducting solenoid with suitable dimensions and field
strength will begin fabrication. A prototype superconducting 201-MHz RF
cavity will be tested. At high gradients, the input power coupler design
will need to be tested and validated. Detuning issues associated with
the pulsed RF system must be evaluated. Finally, because of the large
stored energy in a 201 MHz SCRF cavity, a reliable quench protection
system must be designed and tested. Fabrication of prototype high-power
RF sources will begin, based on the R&D studies carried out previously.

Fiscal Year 2003

For the targetry experiment, high intensity beam tests (≈1 × 1014
particles per pulse) will take place using a selected target and the
20-T capture solenoid; about six weeks of parasitic AGS beam time are
envisioned. A second round of high-intensity tests, now including the
high-gradient 70-MHz RF cavity, will be carried out later in the year,
again needing about six weeks of parasitic beam time. Measurements of
pion yield will be made using the diagnostics built last year. These
will use a much lower beam intensity (≈1 × 106 particles per pulse),
also for 6 weeks of parasitic beam time. The tests of radiation hard
materials will be completed and selected candidate materials will be
used to begin manufacture of an actual (warm) solenoid coil for testing
in a high-radiation environment. Target facility studies will progress
to prototypes or full-size models of key components as needed to verify
the design concepts.

A full cooling cell will be assembled and bench tested. After testing,
it is anticipated that these components will be installed in a muon beam
line and tested with beam. Upon completion of the integration tests,
fabrication of additional components will begin; these will be added to
the beam test line as available to demonstrate a more realistic segment
of cooling channel with appreciable resultant cooling.

Magnet designs suitable for the arcs of the recirculating linacs (RLAs)
and the muon storage ring will be examined this year. Both conventional
and superconducting designs will be compared where either is possible.
With SC magnets, radiation heating becomes an issue and must be assessed
and dealt with. Assessment of field error effects on the beam transport
must be determined to define acceptance criteria for the magnets. This
will require use of sophisticated tracking codes like COSY that permit
rigorous treatment of field errors and fringe-field effects. Because the
beam circulates in each RLA for only a few turns, the sensitivity to
magnet errors should not be extreme, though the large energy spread will
serve to enhance it. Optimization of the RLAs in terms of the number of
passes in each must be done. This depends on the details of the splitter
and recombiner magnet designs and also on the beam energy spread coming
from the cooling channel. Designs for these magnets must be developed
and---depending on how nonstandard they are---prototypes will be
developed. Work on finalizing the optics design for the arcs must be
done. Tests of a low-frequency superconducting RF cavity (201-MHz) will
continue this year, including study of the ability to shield nearby
magnetic fields in a realistic lattice configuration.

The simulation effort this year will focus on understanding experimental
results from the targetry experiment. Additional effort will be given to
beam dynamics studies in the RLAs and storage ring, including realistic
errors. In many ways, the storage ring is one of the most
straightforward portions of a Neutrino Factory complex. However, beam
dynamics is an issue here as the muon beam must circulate for many
hundreds of turns. Use of a tracking code such as COSY is required to
assess fringe field and large aperture effects. As with the RLAs, the
relatively large emittance and large energy spread enhance the
sensitivity to magnetic field and magnet placement errors. Suitable
magnet designs are needed, with the main technical issue being the
relatively high radiation environment. The storage ring optimization
favors long straight sections and short arcs. However, it is advisable
to leave some room in the arcs ("utility" straight sections) for
presently unspecified elements; a lattice design that preserves this
flexibility will be developed and tracked. Another lattice issue that
must be studied is polarization preservation. In the initial
implementation of a Neutrino Factory it is expected that polarization
will not be considered, but it may be important in later phases.
Investigation of what is involved in transporting a polarized beam
through the entire accelerator chain will be completed.

The proton driver group will test a high-gradient, low frequency RF
cavity in a ring, either at BNL or FNAL.

Fiscal Year 2004

For the targetry experiment, the work this year will focus on completing
systems studies of the final target station, including issues of
radiation handling and safety. A (normal conducting) test solenoid coil
based on the materials tests in prior years will be completed and tested
in a radiation environment.

The MUCOOL demonstration will proceed incrementally, adding cells to the
beam line as dictated by financial resources and programmatic
considerations. This process will continue until we have demonstrated
the efficacy of cooling, possibly reaching an emittance reduction of
50%. Simulations in support of this effort will continue.