The U.S. LHC Accelerator Research Program:

Accelerator Systems R&D Plan for FY'06-FY'10

V. Shiltsev, M. Syphers\
Fermi National Accelerator Laboratory\
Batavia, IL 60510

A. Ratti\
Lawrence Berkeley National Laboratory\
Berkeley, CA 94720

T. Markiewicz\
Stanford Linear Accelerator Center\
Stanford, CA 94309

September 2005

# 1. Accelerator Systems R&D Plan

The Accelerator Systems component of the U.S. LHC Accelerator Research
Program continues to address the goals of advancing High-Energy Physics
and advancing U.S. accelerator science and technology, while exploiting
and building on the strengths and interests of the National
Laboratories. Below we give an overview of the different program
elements which address these goals.

Accelerator Systems FY'06 budget is 3,960,000 USD.

Accelerator Systems Level 1 manager is Vladimir Shiltsev (FNAL)

## 1.1. R&D on LHC Instrumentation

In order to bring the LHC up to luminosity as soon as possible, some
specialized instrumentation and diagnostics beyond the usual set may be
required. All of the instruments in the initial suite will be strong
tools for efficient commissioning of the LHC. We have chosen to work on
these because, in addition to enhancing the LHC performance, they push
the state-of-the-art, and in some cases their development can also
contribute to the efficient operation of our own machines. It is decided
that the initial suite of instruments and diagnostics be operational for
LHC first beam, scheduled to be in 2007. Instrumentation projects
developed under LARP will help to commission LHC and will be in
operational use during LHC luminosity operation.

Instrumentation FY'06 budget is 1,530,000 USD

Instrumentation Level 2 manager is Alexander Ratti (LBL)

### Tune Feedback 

Tune, chromaticity and coupling feedback instruments and software are
being developed by LARP for the LHC. Such tools are crucial for
efficient operations with intense beams in superconducting accelerators
to help deal with dynamic effects, particularly during injection and at
the beginning of the ramp. These instruments would be very useful to the
operation of the Tevatron and RHIC, and even more important for the
operation of LHC. Automatic and robust measurement of the tune without
adverse side effects is a challenging problem and is the focus of the
R&D effort. With a reliable tune measurement, a feedback system can be
implemented in software and tested in a straightforward way. The goal is
to control the tune during the acceleration ramp to avoid resonance
crossing and beam loss. The Phase Locked Loop (PLL) method is to shake
the beam and observe the resonant beam transfer function when the
shaking frequency is at the fractional betatron tune. Once the
fractional tune is measured with the PLL, it is used in a feedback
system to regulate the quadrupole current and tune.

Encouraging results with PLL tune feedback system were obtained in RHIC
in 2005, many problems addressed and solved.

*Overall Plan:*

FY2006: Q1 -- make prototype PLL (4 planes) ready for RHIC beam

Q2 - deliver 2 planes to CERN for SPS testing

Q3 - Final Design Review, SPS testing, initial Controls integration
(FESA)

Q4 - finalize architecture

FY2007: Q1 -- make final system (4 planes) ready for RHIC beam

Q2 - deliver final system to CERN, system integration and testing

Q3 - system commissioning with beam

Tune Feedback FY'06 budget is 325,000 USD

Tune Feddback Level 3 manager is Peter Cameron (BNL)

### 1.1.2. Luminometer

    LARP is committed to delivering four ionization gas
luminosity monitors to the LHC, to go on either side of IP1 (ATLAS) and
IP5 (CMS). The devices are ionization gas monitors designed to withstand
the extreme radiation levels of these interaction points. Flowing gas is
needed to ensure that fresh medium is used to prevent radiation damage
effects. At this point there are no plans by anyone to place luminosity
monitors at IP2 (ALICE) and IP8 (LHCb), although experimenters are
petitioning LHC management to do so. (The LHC philosophy is to treat
luminosity monitors as standardized accelerator diagnostics, rather than
as devices belonging to the experiments which are made available to the
accelerator control room.) One possibility would be for CERN to
\"purchase\" 2 or 4 additional ionisation gas monitors from LARP, for
use at IP2 and/or IP8. Since there are no TAN neutral absorbers at IP2
and IP8, installation and integration there would have to be developed
on purpose and could not be the same as at IP1 and IP5.

     In 2005 the LBL group completed and formalized the system
integration document, describing the installation plan at CERN. A test
of the prototype luminosity monitor at the ALS (LBL) X-ray beam line was
very successful and demonstrated 40 MHz capability of the monitor, and
completed the feasibility studies planned for the device.

*Overall Plan:*

FY2006:       Design and build first unit of DAQ system

                      Final design of complete first unit

                      Test prototype at RHIC

FY2007:       Build all units

                     Install and  commission all units at CERN

           Luminometer FY'06 budget is 960,000 USD

           Instrumentation Level 3 manager is Alexander Ratti (LBL)

### 1.1.3. Schottky Monitors

4.7 GHz Schottky monitors will allow continuous and non-destructive
measurements of LHC beam sizes, tunes, and distributions on
bunch-by-bunch basis. Both narrow and wide band systems are potentially
useful. Original 1.7 GHz version of VHF Schottky monitors have
demonstrated their extreme operational usefulness at the Tevatron and
Recycler rings at FNAL, and 4.7GHz Schottky R&D will be a natural
continuation of the method for the LHC beam parameters. Under that task,
LARP will deliver: a complete design and analysis, a drawing package,
the analog signal processing electronics, analysis software,
installation and hardware commissioning support at CERN. CERN will
provide manufacturing and local installation, DAQ system and controls
system integration.

*Overall Plan:*

FY2006: S/N study of low intensity bunches in Tevatron

Design pick-up structure

Study PLL DAB board for DAQ

Design and build front-end electronics

FY2007: Adapt Fermilab analysis software

Hardware commissioning at CERN without beam

FY2008: Hardware commissioning at CERN with beam

FY2009: Beam studies of chromaticity measurements, ramp effects

Schottky Monitors FY'06 budget is 245,000 USD

Schottky Monitors Level 3 manager is Andreas Jansson (FNAL)

### New Instrumentation Initiatives

There are a number of instruments and diagnostics that will possibly be
very useful for the LHC, and for which the U.S. laboratories can supply
expertise, but which are not part of the initial work scope. Either they
are more technologically speculative, their need is not
well-established, or there is generally less interest in them at the
present time. Some of these systems can be productively developed using
the Tevatron or RHIC and be useful in improving the performance of both
the LHC and our domestic accelerators. Other advanced instruments may be
designed to help carry out fundamental accelerator physics
experiments. This work is a continuation beyond the initial suite of
instruments, and it is estimated as a level of effort in later years.

While we cannot firmly predict now what instrumentation we will develop
in the future, we list below some examples. This list is not intended to
be exhaustive. Decisions about whether to support R&D on these or other
devices will be made by the Program Leader with the advice of the
U.S.-CERN Committee at the appropriate time.

Four LHC instrumentation proposals are presently under consideration,
while others are still being developed:

*Zero Degree Calorimeters for Luminosity Monitoring*

  It is proposed to install three Zero Degree Calorimeter (ZDC) modules
on either side of IP1, primarily for use by the ATLAS experiment. This
makes such devices available to the accelerator also for luminosity
monitoring. These ZDCs are derived from those already used very
succesfully in routine operation as standard devices at RHIC. Their
installation at IP5 would \"double up\" luminosity monitors there,
allowing the cross calibration of ZDCs and ionization gas
devices. Sebastian White (BNL) is in the process of making a formal
request to ATLAS, seeking about \$140k in funds. The similarities
between ZDCs and ionization gas devices makes it possible for them to
share the readout electronics, which is already part of the effort
underway at LBL. It is proposed that LARP extend its effort to include
the readout electronics for the ZDCs.

In FY'06 the ZDC proposal will be evaluated and commitment decision will
be made. Sebastian White (BNL) is leading this proposal.

*Synchrotron Light-Based Diagnostics (SyncLight Collector)*

Synctrotron radiation light emitted by LHC protons can be collected and
transported via optical fiber without loss of intensity out of the
tunnel to an above ground signal processing setup. Sub-nanosecond fast
chopping of the light signal chopping can be done by commercially
available instruments and giving longitudinal beam density profiles.
Such a monitor will measure both the shape of individual bunches and the
presence of other beam in "unfilled" RF buckets or not-captured beam,
will be essential for LHC, given the unprecedented stored energy in the
beam. 

Conceptual development of the SLC monitor as well as cost estimate and
schedule planning will take place in FY'06. Max Zolotorev (LBL) is
leading this proposal.

*AC Dipole*

The installation of AC dipoles potentially aids the LHC to
non-destructivelymeasure the linear, near-linear, and non-linear
properties of the beam, by exciting coherent betatron oscillations of
the beam at frequencies very close to the betatron frequency. Perhaps
most important is the potential ability of AC dipoles to rapidly and
efficiently measure the optical beta-functions at the suite of
collimators that are necessary to protect the LHC. Early operating
experience has already been gained with AC dipoles at RHIC in the linear
mode, generating preliminary beta-function measurements of varying
quality. AC dipole experience at RHIC - in design, construction, and in
operation - will be directly relevant to the potential installation of
AC dipoles at the LHC.

In FY'06 we will evaluate effectiveness of the AC dipole for the LHC
measurements, make cost estimates and schedule. S.Peggs (BNL) is leading
this proposal.

*Head-Tail Monitor*

The head-tail chromaticity monitor. originally proposed at CERN, has
been developed at FNAL and is now routinely used for chromaticity
measurements in the Tevatron. In the LHC the large swing in chromaticity
(\> 50 units) at the start of ramp and the short decoherence time will
pose additional challenges. A collaboration between V. Ranjbar (FNAL)
and R.Jones (CERN) has begun to look at improvements to the method. This
method also allows to measure tunes, coupling, lattice functions and has
promise to measure second order chromaticities with better precision
than traditional methods.

In 2006 we will carry out collaborative machine studies in the Tevatron
and SPS to measure chromaticity with reduced emittance blow up and
explore possible extensions to measure higher order chromaticites and
wakefields. Vahid Ranjbar (FNAL) is leading this proposal.

     New Instrumentation Initiatives FY'06 budget is 0,000 USD

          New Instrumentation Initiatives Level 3 manager is Alexander
Ratti (LBL)

## 1.2. LHC Commissioning

There is an overall benefit to the U.S. high-energy physics program if
the LHC turns on rapidly and successfully. Our experimental physics
groups have invested heavily in the LHC project, and the science
produced there thus represents a return on the U.S. investment. A
healthy and strong HEP activity at LHC will surely be necessary to
secure future accelerator-based HEP projects in the U.S. The information
gained during the commissioning will be available in a timely manner and
will have maximum positive effect on U.S. plans for LHC upgrades.

Commissioning FY'06 budget is 1,140,000 USD

Commissioning Level 2 manager is Michael Syphers (FNAL)

### 1.2.1. Beam Commissioning

The Beam Commissioning task consists of :

*Commissioning of LARP Deliverables***:** This includes the
commissioning and exploitation of beam instrumentation developed with
LARP funds, such as luminometers, tune feedback, and phase 2
collimators.

*Generic Beam Commissioning***:** This includes participation in beam
startup, various beam studies, and exploitation of beam instrumentation
other than that developed with LARP funds. Some 30 topics for possible
U.S. contributions were listed by CERN Beam Commissioning leaders and
presented at the LARP collaboration meetings in 2005.

The LHC is scheduled to have first beam in mid-2007. The beam
commissioning activity will begin at least one year before that, in
order to prepare and be sure that our scientists are fully integrated
with the team at CERN. The LHC will be a very difficult machine to
operate, and it is expected to take several years for it to approach its
design performance. Thus we expect commissioning work to extend for
about two years after first beam. By that time, the LHC should be
nearing peak luminosity, and the effort will segue into analysis and
fundamental accelerator physics, using the LHC as an experimental
instrument.

*Overall Plan:*

FY 2006: first visits for commissioning of LARP deliverables organized
and started;

Long term plan (LTP) of general beam commissioning formulated, reviewed
and approved

FY 2007: first year of full involvement of LARP in the LHC beam
commissioning

FY2008-2009: the commissioning effort continues according to the LTP

Beam Commissioning FY'06 budget is 400,000 USD

Beam Commissioning Level 3 manager is Elvin Harms (FNAL)

### 1.2.2. IR and Hardware Commissioning

This task consists of :

*Interaction Region Commissioning***:** This relatively modest and well
defined Task refers to non-beam commissioning of hardware built in the
U.S.-LHC Construction Program, such as interaction region magnets, and
feed boxes. LARP will support 2-3 1-year long visits for that purpose in
FY06-07. The names are identified, the visits are scheduled.

*Hardware Commissioning***:** Strong verbal support has been expressed
by the DOE and U.S. lab directorates for additional hardware
commissioning assistance to CERN, and for the idea that LARP is a
natural vehicle through which this activity could be organized. Any
additional hardware commissioning scope inside LARP would go beyond
"following through on U.S.-built deliverables," to participation, mainly
by engineers, with more general commissioning. In 2005, LARP
Commissioning Task Force identified possibilities to send some 5-7 US
engineers to CERN for general hardware commissioning work -- in addition
to the IR commissioning. Effort required for this new activity is not
included in the current LARP funding envelope.

The entire IR and Hardware commissioning effort will take place in FY'06
and FY'07 -- until the end of the LHC installation and machine
commissioning.

*Overall Plan:*

FY 2006: funding issues to be cleared out and general Hardware
Commissioning to be organized in the first half of FY'06; IR
Commissioning participation started

FY 2007: IR and general Hardware Commissioning efforts continue

IR&Hardware Commissioning FY'06 budget is 540,000 USD

IR&Hardware Commissioning Level 3 manager is Michael Lamm (FNAL)

### 1.2.3. Toohig Fellowships

It is critical that U.S. accelerator physicists and engineers make use
of this relatively rare opportunity to train younger staff members on
the LHC machine. In 2005, the LHC Accelerator Research Program announced
Toohig Fellowships - postdoctoral research positions in accelerator
science for recent PhDs in physics or engineering. These positions are
explicitly for studies and activities concerning CERN\'s Large Hadron
Collider. The term of the Toohig Fellowship is two years extendable to
three, approximately half of which will be spent at CERN and the
remainder at a U.S. DOE laboratory involved in the LARP collaboration.
LARP could support up to two fellowships per year for remaining years of
the Program.

The Fellows are expected to study and improve the operation of the LHC
by helping with commissioning activities, by actively participating in
accelerator research on the collider, beam physics calculations and
simulations, and by pursuing R&D on instruments, magnets, and other
equipment to facilitate a luminosity upgrade.

*Overall Plan:*

FY 2006-2010: up to 2 Toohig Fellows will be selected each year

Toohig Fellowship FY'06 budget is 200,000 USD

Level 3 manager (Toohig Fellowship Committee Chair) is Peter Limon
(FNAL)

### 1.2.4. New Commissioning Initiatives

LARP is currently considering participation in the CMS/LHC Remote Access
Center at Fermilab -- which will support several types of LARP
activities :

-   Participate in LHC hardware & beam commissioning and operations

-   Monitor LHC accelerator components (e.g. systems built in the U.S.)

-   Analyze the monitoring data for LHC

-   Develop software for the LHC

-   Provide access to monitoring data and analysis results

-   Provide training and data-analysis facility for members of US/LARP

-   Provide a rapid response call center to get experts located in North
    America connected to CERN (data access, operational status, etc.)

The ability to participate in experiments remotely from the U.S. may
greatly reduce the travel strain and cost of Accelerator Physics and LHC
beam commissioning activities.

*Overall Plan:*

FY 2006: we will take part in initial discussions on that subject within
framework of the LHC@FNAL Task Force initiated by FNAL Director in April
2005 and led by Eric Gottschalk (FNAL).

New Commissioning Initiatives FY'06 budget is 0,000 USD

New Commissioning Initiatives Level 3 manager is Michael Syphers (FNAL)

## 1.3. LHC Collimation R&D

The LHC cleaning system must have exceptional efficiency to meet its
design parameters, significantly beyond the state-of-the-art that is
achieved in existing colliders. It is crucial for the success of the LHC
that different paths are explored in order to optimize the design,
hardware and operational procedures for the LHC collimation system. In
view of the exceptional difficulty for the LHC it is essential to pursue
parallel R&D studies in- and outside of CERN. The phased approach for
the LHC collimation system will allow to test various proposals and to
implement the best solutions in an already defined upgrade path to
nominal performance. The LHC Collimator R&D will complement the work at
CERN and will be performed in close collaboration.

LHC Collimation R&D FY'06 budget is 850,000 USD

LHC Collimation R&D Level 2 manager is Thomas Markiewicz (SLAC)

### 1.3.1. Cleaning Efficiency Studies

We plan to install and implement at BNL accelerator tracking code
identical with the one used at CERN (K2, SIXTRACK with Collimators, i.e.
SIXTRACKwColl) and perform detailed simulations. SIXTRACK needs to be
adjusted to specific RHIC conditions (single sided collimators); this
effort is currently in progress. Simulations should include apertures
and result in predicted collimation efficiencies and loss maps which
will then be compared to simulation results from earlier studies done at
RHIC with other codes (Teapot, K2, ACCSIM) and with data. Various data
sets at two energies are available.

During the RHIC proton run collimator setup procedures should be
implemented into the RHIC control system and tested with beam under real
operating conditions.

The ultimate goal of this sub program is to bench mark code(s), in
particular SIXTRACKwColl, in a variety of aspects with RHIC beams. Once
the simulation code is installed and cross checked between the labs more
studies can be performed easily ( such as HI scattering, loss maps and
collimator efficiencies).

*Overall Plan:*

FY 2005: code installed, compiled, debugging started

FY 2006: compare with other simulation and data, test setup procedures,
finish reports

Cleaning Efficiency Studies FY'06 budget is 50,000 USD

Cleaning Efficiency Studies Level 3 manager is Angelika Drees (BNL)

### 1.3.2. Rotating Collimators R&D

The ultimate goal of this sub-program is a successful design for low
impedance, high efficiency LHC secondary collimators. The design will be
validated with a sufficient but small (1-3) number of prototypes and
beam tests. The design specifications and the prototypes are the primary
deliverables. The time scale is set by the desirability of testing the
prototypes with LHC beam in 2008/09. Based on the design study,
prototype performance and overall experience with the Phase I
collimation system in actual LHC running conditions, CERN will decide
whether or not to proceed with the rotating collimator design. If a
decision is made to proceed, this sub-project will provide an
engineering drawing package to CERN and will support the effort to
commission the collimators once they are manufactured and installed by
CERN.

*Overall Plan:*

FY 2005: Rotating Collimator mechanical design (RC1) complete

FY 2006: Tests of RC0, Design and construction of functional collimator
(RC1)

FY 2007: Tests of RC1 (two rounds), design and construction of RC2

FY 2008: Non-Beam Tests of RC2

FY 2009: RC2 beam tests & final drawing package for CERN

FY 2010: Await production & installation by CERN

FY 2011: Commissioning support

Rotating Collimator R&D FY'06 budget is 720,000 USD

Rotating Collimator R&D Level 3 manager is Thomas Markiewicz (SLAC)

### 1.3.3. Tertiary Collimator Studies

The Tevatron and HERA experience says, that the backgrounds in the
detectors and protection of expensive detector components is the most
demanding issue to the collimation system performance and efficiency,
and that the tertiary collimators in high-luminosity insertions is an
absolutely necessary component here. Therefore, we plan full tracking --
with the STRUCT code - of secondary halo particles up to the limiting
apertures in the IP1 and IP5 insertions and farther to the CMS and ATLAS
detector inner detectors followed by realistic energy deposition
modeling with the MARS15 code with and without tertiary collimators.

Minimization of machine-related backgrounds and protection of the final
focus and collider detector components at normal operation and
accidental beam losses is to be added to the collimation system
specifications. This is to be done with the appropriate simulation
tools, thorough benchmarked and further developed if needed, in a close
collaboration with the CERN LHC collimation team, with all the necessary
iterations on the LHC lattice, detector and collimator models. The
ultimate goal is a successful design for high efficient robust tertiary
collimators in all the LHC experimental insertions. The design
specifications are the primary deliverables.

*Overall Plan:*

FY 2005: Calculational model built

FY 2006: First studies and ptimization of the tertiary collimator
performance

FY 2007: Engineering design, extension to heavy-ion mode of operation

FY 2008: Studies towards luminosity upgrade

FY 2009: Studies towards luminosity upgrade

FY 2010: Engineering design and production

FY 2011: Commissioning

Tertiary Collimator Studies FY'06 budget is 30,000 USD

Tertiary Collimator Studies Level 3 manager is Nikolai Mokhov (FNAL)

### 1.3.4. Material Irradiation Studies

Material irradiation studies will provide indicators of how prone LHC
collimator materials are to changing physical and mechanical properties,
important to the beam collimating function, with the onset of
irradiation. Behavior of wide range of materials from low to high Z
under irradiation and post-irradiation to be studied at BNL. The main
phase of the irradiation study uses the 200 MeV beam of the BNL BLIP (\~
70μA average current). It is expected to induce approximately 0.25 dpa
on the materials and will provide initial screening.

To address potential issues with materials considered for Phase 2
collimators, the effects of irradiation on the driving design parameters
must be established early on and thus guide the final selection and the
design. Specifically, materials that are being discussed are Beryllium,
Copper, Aluminum, Inconel, Tungsten, Titanium alloys and AlBeMet (alloy
of Beryllium and Aluminum). Understanding of how irradiation primarily
degrades thermal conductivity (as well as other physical and mechanical
properties such as ductility, strength, fracture temperature, etc.) is
of paramount importance in the Phase II study which is exploring a
number of options.

*Overall Plan:*

FY 2005: Irradiation of LHC samples with 200 MeV protons at BNL BLIP
/Hot Cell facility and with high energy protons at either BNL AGS or
FNAL

FY 2006: Continuation BLIP studies, start of irradiation studies with
high energy protons at either BNL AGS or FNAL

FY 2007: Post irradiation analysis of material properties

Material Irradiation Studies FY'06 budget is 50,000 USD

Material Irradiation Studies Level 3 manager is Nikolaos Simos (FNAL)

## 1.4. Accelerator Physics R&D

LHC, as a frontier machine, pushes the parameters to the limit where one
can learn the most. Accelerator physics activities will require a mix of
calculation, simulation and experimentation. Some of these activities
can be done at home institutions in the U.S. Others will require
presence at CERN because some experiments important for future colliders
can be done only at the LHC, where the average and peak currents are
high, and where synchrotron radiation is a significant effect. The
results of these calculations, simulations and experiments will give us
the knowledge to design and build with confidence the next generation
hadron collider.

Accelerator Physics FY'06 budget is 640,000 USD

Acting Accelerator Physics Level 2 manager is Vladimir Shiltsev (FNAL)

### 

### 1.4.1. Electron Cloud Simulations

The electron cloud effect is a significant problem in many of the
current generation of high intensity electron-positron and hadron
colliders. In the LHC, the electron cloud effect, if uncontrolled, is
expected to cause excess power deposition on the cryogenic beam screen
and an increase in beam emittance. LBL was an early participant in
studying the electron cloud effect, developing one of the first
simulations during the design and construction of PEPII, and then
applying it the LHC. Electron clouds have been detected in SPS, RHIC,
and in the Tevatron. RHIC and the Tevatron are cryogenic test beds
similar to the LHC. Measurements, simulations, and analytical work will
contribute to a better understanding of the electron cloud effect.
Conversely, the ongoing efforts at CERN to describe and model electron
cloud effect will benefit current and future U.S. Collider performance.

Experimental data on electron cloud effects during recent SPS run had
been acquired and they will be used for EC codes calibration. In
addition, we intend to better understand the ECE in the cold sections of
RHIC.

*Overall Plan:*

FY2006: Complete the analysis of June 2004 SPS run

> Additional SPS studies including bunchlength dependence
>
> Finish LHC heat-load estimate and POSINST-ECLOUD benchmarking

Define optimal LHC conditioning scenario and fill pattern during first
two years of beam operations

FY2007: Perform 3D simulations bunch trains, beam instability for LHC
arcs

> Report on applicability of Iriso-Peggs maps to LHC
>
> Report on e-cloud simulations for RHIC detectors, predict BBB tune
> shift

FY2008: Report on e-cloud simulations for LHC IR4 "pilot diagnostic
bench"

Electron Cloud Simulations FY'06 budget is 200,000 USD

Electron Cloud Simulations Level 3 manager is Miguel Furman (LBL)

### 1.4.2. IR Design and Beam Beam Simulations

The nominal beam parameters of the LHC take it into beam-beam territory
beyond current hadron colliders. The beams will have a finite crossing
angle, and thus the closely spaced bunches will also undergo multiple
long-range parasitic collisions at each interaction region. The Tevatron
experience has shown importance long-range beam-beam interactions that
are likely to limit the luminosity in the LHC. Experimental observations
at Tevatron and RHIC to be backed up by simulations using
\"strong-strong\" beam-beam codes that are under development at LBL,
which is the site for both the NERSC supercomputing center and the
Sci-DAC supported Accelerator Modeling and Advanced Computing group. The
results of these studies can help guide the strategies at LHC for
dealing with beam-beam effects, and will help guide the design of a
second generation IR for a luminosity upgrade. As the LHC comes into
operation, it will become the direct focus of the experimental and
theoretical programs on beam-beam effects within the LARP.

All LHC upgrade scenarios require integrated analysis and development by
accelerator physicists and magnet builders, in both the U.S. and in
Europe, and the development of the Interaction Region optics is central
to this integration. For example, the \"dipole first\" and \"dipole
last\" scenarios depend on whether the beam is split into two beam pipes
before or after the quadrupole triplet. Placing the dipole first is
effective in reducing the deleterious effects of the bean-beam,
interaction, but incurs a significant heat load from luminosity
radiation products. Accelerator Physicists in LARP will work closely
with magnet designers to generate an upgraded IR design, consistent with
the timescale on which CERN is ready and able to down select from the
many upgrade scenarios currently on the table.

*Overall Plan:*

FY2006: Design concepts for the IR upgrade will be explored in greater
detail. Develop matched designs that can be used from injection to
collision.

Develop non-linear correction schemes for both Dipole-first (DF) and
Quadrupole-first (QF) designs

Energy deposition and magnet protection considerations for both designs

Study interference of TOTEM and ZDCs with IR systems

Benchmark code against Tevatron and RHIC beam-beam observations and
CERN's fast-multipole code

FY2007: Application of BEAMBEAM3D to halo formation, luminosity monitor
(swept beams).

Explore in simulations long-term emittance growth and working point
dependencies

FY2008: Plans to be determined after obtaining previous years results.

IR Design And Beam-Beam Simulations FY'06 budget is 260,000 USD

IR Design and Beam-Beam Simulations Level 3 manager is Tanaji Sen (FNAL)

### Wire Beam-Beam Compensation R&D

It was recently proposed to compensate LHC long-range interaction
effects by placing several current carrying wires in vicinity of the
beams close to main IPs. Beam experiments with wires in SPS showed that
one wire can compensate detrimental effects caused by another wire. LARP
is supporting an experimental test of the wire compensation at RHIC
which provides unique environment to study experimentally long-range
beam-beam akin to LHC operation. The experiment assumes installation of
a wire compensator on a movable stand in one of the RHIC rings.

*Overall Plan:*

FY2006: Design and construct a wire compensator

Install wire compensator in RHIC in summer 2006, downstream of Q3 in IR6

> Perform theoretical studies to test the compensation and robustness

FY2007: Study the wire compensation in RHIC with 1 proton bunch in each
beam and nominal conditions at flat top and 1 parasitic interaction.

Beam studies to test tolerances on: beam-wire separation compared to
beam- beam separation, wire current accuracy and current ripple

FY2008: Decide on scope of work for the LHC wire compensation

Wire Beam-Beam Compensation FY'06 budget is 180,000 USD

Wire Beam-Beam Compensation Level 3 manager is Tanaji Sen (FNAL)

### 1.4.4 New Accelerator Physics Initaitives

*Field fluctuation measurements*

It was recently pointed out, that the beam screen inside the LHC dipole
magnets is subject of microkicks due to turbulent flow of 20K Helium
used for its cooling. Miniscular fluctuations of the beam screen shape
caused by these kicks will result in field fluctuations at frequency
range including lowest betatron lines. Emittance growth due to such
fluctuations can be of concern for he LHC integrated luminosity if their
magnitude exceed dB/B\~1E-10. The fluctuations can be directly measured
using Faraday induction coil probes.

*Overall Plan:*

FY 2006: elaborate preparations of the measurement coils, DAQ and LHC
MTF, testing and calibration of the equipment

FY2007: measurements begin, dB/B measured at different He temperatures
and flow rates

New Accelerator Physics Initiatives FY'06 budget is 0,000 USD

New Accelerator Physics Initiatives Level 3 manager is Vladimir Shiltsev
(FNAL)