+------------+-----------------------+------+---+---------+--------------+
| ![](media/ | WBS 1.4.1 -- Booster  |      |   |         |              |
| image1.png | and AGS               |      |   |         |              |
| ){width="1 | Infrastructure        |      |   |         |              |
| .401388888 | Improvements          |      |   |         |              |
| 8888888in" | Reference Document    |      |   |         |              |
| height="0  |                       |      |   |         |              |
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|            |                       | Modi | * |         | Version :    |
|            |                       | fied | * |         | **2.11**     |
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| *Prepared  |                       |      |   | *A      |              |
| by:*       |                       |      |   | pproved |              |
|            |                       |      |   | by:*    |              |
| K.A. Brown |                       |      |   |         |              |
|            |                       |      |   | QA      |              |
| *With      |                       |      |   | Review  |              |
| I          |                       |      |   | er(TBD) |              |
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| **Ab |      |          |                                            |   |
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|      |      |          |                                            |   |
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| In   |      |          |                                            |   |
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| The  |      |          |                                            |   |
| AGS  |      |          |                                            |   |
| in   |      |          |                                            |   |
| fras |      |          |                                            |   |
| truc |      |          |                                            |   |
| ture |      |          |                                            |   |
| impr |      |          |                                            |   |
| ovem |      |          |                                            |   |
| ents |      |          |                                            |   |
| are  |      |          |                                            |   |
| impr |      |          |                                            |   |
| ovem |      |          |                                            |   |
| ents |      |          |                                            |   |
| that |      |          |                                            |   |
| the  |      |          |                                            |   |
| Coll |      |          |                                            |   |
| ider |      |          |                                            |   |
| Acc  |      |          |                                            |   |
| eler |      |          |                                            |   |
| ator |      |          |                                            |   |
| de   |      |          |                                            |   |
| part |      |          |                                            |   |
| ment |      |          |                                            |   |
| (C   |      |          |                                            |   |
| -AD) |      |          |                                            |   |
| at   |      |          |                                            |   |
| Br   |      |          |                                            |   |
| ookh |      |          |                                            |   |
| aven |      |          |                                            |   |
| Nati |      |          |                                            |   |
| onal |      |          |                                            |   |
| La   |      |          |                                            |   |
| bora |      |          |                                            |   |
| tory |      |          |                                            |   |
| (    |      |          |                                            |   |
| BNL) |      |          |                                            |   |
| has  |      |          |                                            |   |
| f    |      |          |                                            |   |
| ound |      |          |                                            |   |
| are  |      |          |                                            |   |
| n    |      |          |                                            |   |
| eces |      |          |                                            |   |
| sary |      |          |                                            |   |
| for  |      |          |                                            |   |
| o    |      |          |                                            |   |
| pera |      |          |                                            |   |
| tion |      |          |                                            |   |
| of   |      |          |                                            |   |
| the  |      |          |                                            |   |
| RSVP |      |          |                                            |   |
| expe |      |          |                                            |   |
| rime |      |          |                                            |   |
| nts, |      |          |                                            |   |
| MECO |      |          |                                            |   |
| and  |      |          |                                            |   |
| KO   |      |          |                                            |   |
| PIO, |      |          |                                            |   |
| wit  |      |          |                                            |   |
| hout |      |          |                                            |   |
| im   |      |          |                                            |   |
| pact |      |          |                                            |   |
| to   |      |          |                                            |   |
| the  |      |          |                                            |   |
| o    |      |          |                                            |   |
| pera |      |          |                                            |   |
| tion |      |          |                                            |   |
| of   |      |          |                                            |   |
| B    |      |          |                                            |   |
| NL's |      |          |                                            |   |
| Rela |      |          |                                            |   |
| tivi |      |          |                                            |   |
| stic |      |          |                                            |   |
| H    |      |          |                                            |   |
| eavy |      |          |                                            |   |
| Ion  |      |          |                                            |   |
| Coll |      |          |                                            |   |
| ider |      |          |                                            |   |
| (RH  |      |          |                                            |   |
| IC). |      |          |                                            |   |
+------+------+----------+--------------------------------------------+---+
| *    |      |          |                                            |   |
| *His |      |          |                                            |   |
| tory |      |          |                                            |   |
| of   |      |          |                                            |   |
| C    |      |          |                                            |   |
| hang |      |          |                                            |   |
| es** |      |          |                                            |   |
+------+------+----------+--------------------------------------------+---+
| Rev. | Date | Sections | Description of changes                     |   |
| No.  |      |          |                                            |   |
+------+------+----------+--------------------------------------------+---+
| 1.00 | 4/1  | All      | Initial version containing descriptions of |   |
|      | 3/04 |          | each system.                               |   |
| 2.00 |      | All      |                                            |   |
|      | 9/2  |          | Updated to reflect major changes to        |   |
|      | 8/04 |          | initial WBS. Changes include scope of      |   |
|      |      |          | project, which now includes Booster/AGS    |   |
|      |      |          | Modifications originally in the KOPIO and  |   |
|      |      |          | MECO WBS structures, and other changes     |   |
|      |      |          | reflecting items that properly must be     |   |
|      |      |          | covered by RHIC operations and not RSVP.   |   |
+------+------+----------+--------------------------------------------+---+

Table of Contents

[1. Introduction 4](#introduction)

[2. Requirements 5](#requirements)

[2.1 AGS Booster Requirements 5](#ags-booster-requirements)

[2.2 AGS Requirements 5](#ags-requirements)

[2.3 AGS Switchyard Requirements 5](#ags-switchyard-requirements)

[2.4 Safety Requirements
5](#safety-and-environmental-protection-requirements)

[3. Description 5](#description)

[3.1 AGS Booster 5](#ags-booster)

[3.2 AGS 11](#ags)

[3.3 AGS Switchyard 14](#ags-switchyard)

[3.4 Safety 18](#safety-and-environmental-protection-1)

[4. Summary 18](#summary)

[5. References 18](#references)

![](media/image2.jpeg){width="5.65625in" height="3.9590277777777776in"}

> Figure 1 -- Booster/AGS complex.

# Introduction

> Both RSVP experiments have demanding beam requirements and will cause
> significant activation of the accelerator components. Table 1
> summarizes the RSVP parameters along with the nominal operating
> parameters for slow extracted beam from the AGS. To meet those
> requirements C-AD has evaluated all the systems required for high
> intensity protons operations and identified those systems that require
> updating and repair.
>
> Table 1: RSVP Parameters

+-------------------+----------------+----------------+----------------+
| >                 | > Normal SEB   | > KOPIO        | > MECO         |
+-------------------+----------------+----------------+----------------+
| > P (GeV/c)       | > 25.5         | > 25.5         | 7.5            |
+-------------------+----------------+----------------+----------------+
| > Rep. Time (sec) | > 5.3          | > 5.3          | > 1            |
+-------------------+----------------+----------------+----------------+
| > Spill Length    | > 3            | > 3            | > 0.5          |
| > (sec)           |                |                |                |
+-------------------+----------------+----------------+----------------+
| > Intensity       | > \> 70        | > 100 TP/pulse | > 40 TP/pulse, |
|                   | > TP/pulse     |                | > 2 bunches    |
+-------------------+----------------+----------------+----------------+
| > Bunch lengths / | > DC           | > 200 psec /   | > \~10 nsec /  |
| > spacing         |                | > 40 nsec      | > 1.35 usec    |
+-------------------+----------------+----------------+----------------+
| > dp/p (%)        | > 0.7 - 0.9    | > \< 0.5       | > \~ 1.0       |
+-------------------+----------------+----------------+----------------+
| > Int. Intensity  | > 7x10^20^     | > 9x10^20^     | > 4x10^20^     |
| > (# protons)     | >              |                |                |
|                   | >              |                |                |
|                   |  (post-Booster |                |                |
|                   | > sum)         |                |                |
+-------------------+----------------+----------------+----------------+
| > Extinction      | > NA           | > 10^-3^       | > 10^-9^       |
+-------------------+----------------+----------------+----------------+

# Requirements

> The C-AD complex is very versatile, with the capability of operating
> multiple programs simultaneously (via pulse to pulse modulated time
> sharing, PPM) as well as the ability to make fast changes of state (a
> change in state taking a few minutes and is done entirely via computer
> controls, called a mode switch). In general, if a given program can be
> performed in a time sharing mode (either via PPM or a mode switch)
> then we would define that program capable of concurrent mode
> operation.

## AGS Booster Requirements

> The AGS Booster must be capable of delivering ions to the NASA Space
> Radiation Laboratory (NSRL), ions to the AGS, polarized protons to the
> AGS, and protons to the AGS. The delivery of ions and/or protons may
> be accomplished in concurrent mode operation. The AGS Booster must not
> be activated beyond what is maintainable by C-AD trained personnel.

## AGS Requirements

> The AGS must be capable of delivering ions to RHIC, polarized protons
> to RHIC, and protons to RSVP. The delivery of ions and/or protons may
> be accomplished in concurrent mode operation. The AGS must not be
> activated beyond what is maintainable by C-AD trained personnel.

## AGS Switchyard Requirements

> The AGS Switchyard must be capable of delivering high intensity
> protons to RSVP experiments and ions to a high energy NASA Space
> Radiation facility (hereafter denoted NSRF). The operation of RSVP and
> the NSRF cannot be concurrent. High intensity protons must not
> activate NSRF components. The operation for NSRF is fundamentally
> incompatible with high intensity operation. The main reason for this
> incompatibility is the NSRF users require frequent tunnel access and
> their equipment cannot be unduly activated. The AGS Switchyard must
> not be activated beyond what is maintainable by C-AD trained
> personnel.

## Safety and Environmental Protection Requirements

> The C-AD has a program to keep radiation exposure to C-AD workers to
> as low as reasonably achievable (ALARA) and manages radiation levels
> for environmental protection. C-AD follows strict guidelines and
> follows a rigorous review process for all systems. Safety systems
> include access controls to radiation areas, active radiation
> monitoring to ensure radiation levels follow predetermined guidelines,
> and ground water activation monitoring.

# Description

## AGS Booster

> The AGS Booster accepts ions from the Tandem Van de Graff, polarized
> protons from the 200 MeV Linac, and high intensity protons from the
> 200 MeV Linac. The AGS Booster is a rapid cycling accelerator used to
> fill the AGS with ions and/or protons (1.94 GeV protons) and to slow
> extract ions to NSRL (1 GeV/n ions). Modifications to the AGS Booster
> for RSVP will ensure operation for RSVP without impact to either RHIC
> or NSRL.

### Conventional Infrastructure

> Tunnels, buildings, services and access points exist and are already
> maintained under existing contracts. The only area of concern is aging
> cable trays in the tunnels. These are explicitly identified in the
> WBS. RSVP should be concerned about this infrastructure component,
> since we do identify damage to cables, and work will be performed in
> and around the cable trays. A safety review of this work must identify
> whether the trays are safe. We must include in our contingency the
> possibility of supporting further repair and/or upgrade of portions of
> the cable tray systems.

### Electrical

> There are a number of areas where cables are getting old and brittle,
> or have become radiation damaged or damaged in other ways. These
> cables would be repaired or replaced or removed if they are no longer
> in use in advance of running high intensity. If this work is not done
> before high intensity running then there is much greater risk that
> further activation during high intensity operations will accelerate
> failure rates in the cables. They also pose hazards to C-AD personnel
> who may have to work on or near the cables. Additionally, the
> radiation burden to workers will be unacceptable if they have to do
> cable repair in areas that have high levels of residual radioactivity
> following high-intensity running periods. It is important to note that
> damaged cables pose the risk of fire and electrocution. A fire could
> have a significant programmatic impact and potential for electrocution
> is an unacceptable risk.
>
> There are a number of magnet coils which have become damaged over the
> years and C-AD managers have determined that a failure rate of one
> magnet per year should be expected during high intensity operations.
> In order to be prepared for this we plan to purchase 6 coil sets
> during the construction phase. Included in the construction cost
> estimate is the cost to replace one set of coils. During RSVP
> operations we expect to repair one magnet per year. If this is not
> done then further activation from high intensity protons will increase
> the risk that a magnet will fail during operations. This has the
> potential of adversely affecting RHIC and NASA operations. If we have
> the parts for a repair of a shorted magnet, then the repair time will
> take at least one week (longer if it requires cool-down time). If we
> don't have the parts for the repair (e.g., magnet coils), then it
> could result in a three to six month shutdown to allow requisition of
> the parts, testing and installation.
>
> The pulse forming networks (PFN's) for the Booster F3 extraction
> kicker power supply and associated capacitor bank have received
> significant radiation dose over many years of operation and are in
> need of replacement. Included in the WBS is a redesign of the
> capacitor banks, to reduce radiation damage in future high intensity
> operation, and to replace aging and radiation damaged components. If
> this is not done then further activation from high intensity protons
> will increase the risk that the charging system for the extraction
> kicker will fail during operations. The extraction kicker is required
> for RHIC operations. This will have significant impact on the
> operating schedule, since a repair will require at least one week,
> without cool-down time, and many months if we have to requisition
> parts.

### Mechanical

> In the critical path to operation of any RHIC or AGS program at the
> C-AD is the extraction septum magnet (F6) for the Booster. A spare is
> included in the RSVP WBS. Operationally RHIC will not significantly
> activate this magnet. If this work is not done then further activation
> from high intensity protons will increase the risk of a magnet failure
> and would adversely affect RHIC and NASA operations, as well as RSVP.
>
> ![](media/image3.jpeg){width="5.295138888888889in"
> height="2.046527777777778in"}

Figure 2: F6 location in the Booster.

> Beam losses at Booster injection are the most significant source of
> residual activation in the Booster. A particular problem is activation
> due to the beam scraping and associated stripping of the H- beam that
> is injected before the H- stripping foil. This has led to the failure
> of the Booster main dipole at C5, which is a special design for the
> injection of protons. A hole is bored through the side laminations to
> allow the H- beam to enter from the transfer line. In addition the
> foil stripping of H- to H+, which occurs in the upstream section of
> the C6 straight section, is not 100 % efficient. A fraction of 1 % of
> the H- leaves the foil as neutral beam and this beam ends up in the C7
> main dipole. This magnet was replaced after it developed a short to
> ground in 1998. Methods to reduce this activation are being discussed.
> Methods include going to thicker stripping foils, the use of secondary
> stripping of the neutral beam after the foil, and limiting acceptance
> of the transfer line to prevent beam scrapping at the entrance of the
> C5 magnet. Nevertheless, if this work is not done then further
> activation from high intensity protons will increase the risk of a
> magnet failure and would adversely affect RHIC and any AGS NASA
> operations, as well as RSVP.
>
> ![](media/image4.jpeg){width="5.950694444444444in"
> height="3.2506944444444446in"}

Figure 3: Injection region in the Booster. Red arrow shows where H- is
injected.

> To further reduce activation on Booster components, an improvement to
> the beam dump is envisioned, with the addition of a set of primary
> collimators to the B6 beam dump (which could act as a beam scrapper
> and/or a secondary collimator). This addition needs further study.
> This has the potential of improving the operation of RSVP experiments
> by allowing ALARA limits to be raised in the Booster, if components
> other than the collimators and beam dump can be less activated.

###  RF

> To improve the operation of the RF and allow for multiple modes of
> operation, the Band III RF cavities were modified with RF fast
> feedback. This feedback allows the RF system to compensate for high
> intensity and operate with greater stability. Adding RF feedback to
> the Band II cavities is included in the WBS. Modifications of the Band
> III system will be done also, since for high intensity operation both
> systems are in use and additional modifications are required when beam
> loading becomes significant. This is in an important item for RSVP
> operations and will improve the stability of the beam intensities and
> may allow higher intensities to be achieved. If this work is not done
> it will not impact RHIC or NASA operations, but will have an impact
> the beam performance for RSVP.

###  Instrumentation

> There are a number of issues related to the instrumentation in the
> Booster.

1)  The Booster loss monitor system is old, has become extremely
    unreliable, and needs repair and upgrades. Included here is
    replacement of old gas lines and new data acquisition system. Not
    doing this work will not adversely affect RHIC or NASA operations.
    It is a critical system that is required for high intensity
    operations, since it is used to alarm on high losses and defines
    thresholds for ALARA limits.

2)  There are two wall current monitors in the Booster. One is used
    exclusively for the RF system, to provide a reference for the phase
    loops while the other is available for measurements. The new wall
    monitor added in FY03 was designed for high intensity, but suffers
    from a frequency response problem. A new design is required as well
    as data acquisition. Not doing this work will not adversely affect
    RHIC or NASA operations. It is crucial for high intensity
    operations, since the frequency response problem prevents resolving
    high frequency instabilities with the high intensity beams.

3)  The C3 inflector is used to inject heavy ions into the Booster (see
    figure 3, on p. 7). In October 2003 it was found that the septum of
    the inflector was distorted (see figure 4, below). Historically it
    was necessary to operate with a vertical offset of the heavy ion
    beams during injection. After repairing the septum it was no longer
    necessary to operate with the vertical offset. Protecting the septum
    from the high intensity proton beams is required. A protection
    system will be designed and built. This particular item is extremely
    important, since it has the potential of seriously affecting RHIC
    and NASA operations.

> ![](media/image5.jpeg){width="3.5555555555555554in"
> height="2.6666666666666665in"}![](media/image6.jpeg){width="3.5555555555555554in"
> height="2.6666666666666665in"}

Figure 4: Photographs of the damaged C3 inflector (the "folded" sheet
should be flat).

4)  Repair/replacement of radiation damaged or old cables. If this work
    is not done then there is much greater risk that further activation
    during high intensity operations will accelerate failure rates in
    the cables. They pose a fire hazard and pose an electrocution hazard
    to C-AD personnel who may have to work on or near the cables.

5)  BTA instrumentation will have some modifications made to allow
    remote gain switching between heavy ions and high intensity protons.
    Not doing this work will not adversely affect RHIC or NASA
    operations. It will affect RSVP, since the ability to change gains
    remotely will hamper setup of the Booster to AGS transfer line with
    high intensity protons during RHIC or NASA operations.

### Controls

> The following controls items must be addressed to ensure maintainable
> delivery of high intensity protons:

1)  Standard VME interfaces will be provided for the instrumentation
    systems listed in ***3.1.5*** (items 1, 2, 3, and 5).

2)  Software and database engineering will be needed for both new
    front-end interfaces and console level applications that must be
    modified to connect with them.

> Not doing this work will adversely affect RSVP operations, since
> existing legacy controls hardware contains obsolete components that
> are un-maintainable.

### Safety and Environmental Protection

> New policies at BNL require that groundwater activation cannot exceed
> 5 % of the EPA drinking water limit. In order to meet this requirement
> we must put water impervious covers, called caps, over the
> soil-shielding covering the accelerator tunnels. The cost for these
> caps is borne entirely by RSVP, since RHIC and NASA operations do not
> produce significant enough radiation, except at the dump that is
> already capped, to exceed the 5% limit. High intensity proton
> operations do produce significant radiation in all soil-shielded areas
> of the Booster Ring, and calculations show that the amount of beam
> loss required to exceed the 5 % level is not detectable, and therefore
> avoidable, with existing instrumentation. Therefore all shielding
> covering the Booster and AGS tunnels will have caps installed.
>
> Figure 5 shows the existing shielding covers for the Booster and the
> AGS. The dark blue areas are concrete caps, covered with an impervious
> membrane, to prevent rain water from filtering through the soil over
> the tunnel. The light green area is a water impervious membrane
> covering the NRSL beam line, a beam line that was built after the 5%
> limit went into affect. The solid red area is a region that will be
> covered on existing funds (outside of RSVP). The hashed orange areas
> over the AGS are regions that are covered with a mixture of concrete
> and soil. It is not known, at this time, whether the soil/concrete mix
> areas prevent rain water from filtering through the soil. This will be
> determined by measuring the moisture content of the soil underneath.

![](media/image7.jpeg){width="7.25in" height="6.757638888888889in"}

Figure 5: existing shielding coverings over the Booster and AGS.

## 

##  

## AGS

> The AGS accepts ions, polarized protons, and high intensity protons
> from the Booster. The AGS is a conventional accelerator used to fill
> RHIC with ions and/or polarized protons and to slow extract ions and
> high intensity protons to fixed target experiments. Modifications to
> the AGS for RSVP will ensure operation for RSVP without impact to
> RHIC.

### Conventional Infrastructure

> Tunnels, buildings, services and access points exist and are already
> maintained under existing contracts. The only area of concern
> identified by C-AD managers is aging cable trays in the tunnels. These
> are explicitly identified in the WBS. RSVP should be concerned about
> this infrastructure component, since we do identify damage to cables,
> and work will be performed in and around the cable trays. A safety
> review of this work must identify whether the trays are safe. We must
> include in our contingency the possibility of supporting further
> repair and/or upgrade of portions of the cable tray systems.

### Electrical

> There are a number of areas where cables are getting old and brittle,
> or have become radiation damaged or damaged in other ways. These
> cables would be repaired or replaced or removed if they are no longer
> in use in advance of running high intensity. If this work is not done
> before high intensity running then there is much greater risk that
> further activation during high intensity operations will accelerate
> failure rates in the cables. They also pose hazards to C-AD personnel
> who may have to work on or near the cables. Additionally, the
> radiation burden to workers will be unacceptable if they have to do
> cable repair in areas that have high levels of residual radioactivity
> following high-intensity running periods. It is important to note that
> damaged cables pose the risk of fire and electrocution. A fire could
> have a significant programmatic impact and potential for electrocution
> is an unacceptable risk.
>
> There are a number of magnet coils which have become damaged over the
> years and C-AD managers have identified a set of magnets which have
> received the highest beam losses and would have coils replaced in
> advance to running high intensity. If this is not done then further
> activation from high intensity protons will increase the risk that the
> magnet will fail during operations. This has the potential of
> adversely affecting RHIC and NASA operations.
>
> Main Magnet ripple has been evaluated and the plan for improving it
> requires a new active filter power supply. If this is not done it will
> seriously affect RSVP operations. Ripple structure on the slow
> extracted beam needs to be minimized in order to keep individual bunch
> intensities for both RSVP experiments as uniform as possible. In
> addition, the dynamics of the slow extraction process for bunched and
> micro-bunched slow extraction are such that bunch widths and
> extinction rates have dependencies on the amount of ripple structure
> seen by the beam.
>
> The F5 (thin) and F10 (thick) septa are critical components for slow
> extraction for RSVP. New low ripple power supplies for the new magnets
> is included. If this is not done it will seriously affect RSVP
> operations since the risk of failure using the existing supplies
> (assuming they are compatible with the new magnets) is considered very
> high due to their age (\>30 yrs) and current condition.
>
> In the last slow extraction run we learned that the J10 beam dump bump
> power supply was a significant source of beam spill ripple. A new low
> ripple power supply is included to eliminate this problem. If this is
> not done it will seriously affect RSVP operations since it has a
> significant affect on the beam spill structure.
>
> The pulse forming networks (PFN's) for the AGS A5 injection kicker
> power supply and associated capacitor bank have received significant
> radiation dose over many years of operation and are in need of
> replacement. Included in the WBS is a redesign of the capacitor banks,
> to reduce radiation damage in future high intensity operation, and to
> replace aging and radiation damaged components. If this is not done
> then further activation from high intensity protons will increase the
> risk that the charging system for the extraction kicker will fail
> during operations. The extraction kicker is required for RHIC
> operations. This will have significant impact on the operating
> schedule, since a repair will require at least one week, without
> cool-down time, and many months if we have to requisition parts.

### Mechanical

> In the critical path to operation of RSVP is the extraction septa in
> the AGS. There are three devices used in the extraction process, an
> electrostatic septum, a thin magnet septum (F5), and a thick magnetic
> septum (F10). The existing devices are old, and do not have sufficient
> aperture for the high intensity RSVP beams (in particular for MECO,
> which is lower energy extraction). The current electrostatic septum
> design may adversely affect the AGS impedance significantly, so part
> of the new design is to evaluate this and develop a design that has a
> minimal impact on the impedance. Figure 6 shows the current AGS septum
> and the septum used at CERN, which is our model for a new design. The
> AGS impedance is an important issue for high intensity operations
> since beam instabilities are a function of the impedance.
>
> The measured beam emittances for high intensity protons, made in 1996,
> are ε~h~^99%,N^ = 98 π mm-mrad and ε~v~^99%,N^ = 85 π mm-mrad. To make
> the acceptance of the electrostatic septum (H20) and the thick
> magnetic septum (F10) \>99 π mm-mrad for 8 GeV protons we require the
> following specifications: (Currently F10 and H20 gaps are \~20 mm)
>
> F5 F10 H20
>
> Horz. gap (mm) 44.45 38.1 10 - 30 (variable gap)
>
> Vert. gap (mm) 25.4 30.4 30.4
>
> Length (m) 0.667 0.81+1.22=2.03 2.3
>
> Septum (mm) 0.76 13.5/15.85 0.051
>
> Bend (mrad) 1.1 18.5 0.43
>
> Field (max) 2.1 kG 14.4 kG 80 kV/cm
>
> ![](media/image8.jpeg){width="3.020138888888889in"
> height="3.1756944444444444in"}![](media/image9.jpeg){width="3.702777777777778in"
> height="2.873611111111111in"}
>
> Figure 6: AGS electrostatic septum (left) and CERN electrostatic
> septum (right).
>
> A careful review of vacuum chamber grounds, insulation, and RC
> networks has been done and a plan has been developed to best reduce
> the impedances due to the vacuum chamber and to prevent beam/rf noise
> from radiating into other equipment. These are significant issues
> during high intensity operation. If this is not done, it will
> seriously affect RSVP operations and potentially affects RHIC
> operations.
>
> New coils are identified for the AGS sextupoles, which have not been
> replaced in over 40 years and cannot accept the higher currents
> required for developing higher intensity beams. In an existing
> improvement project 12 sextupole coils have been replaced. For this
> project, we would utilize this new coil design and replace 16 more
> coils in the AGS. If this is not done, it will seriously affect RSVP
> operations.
>
> As in the Booster, the addition of collimators in the AGS may allow
> ALARA limits to be raised, permitting a higher throughput of particles
> to the RSVP experiments.

### RF

> At this time, no AGS RF issues have been identified.

### Instrumentation

> There are a number of issues related to the instrumentation in the
> AGS.

1)  The AGS long loss monitor system is becoming old and needs repair
    and upgrades. Included here is replacement of old gas lines and
    detectors, and new electronics. This system is critical for high
    intensity operations, since it is our primary monitor of extraction
    efficiency and is used for operations ALARA alarm monitoring.

2)  There is one wall current monitor in the AGS. It historically
    suffers serious degradation problems during high intensity
    operation. A new design that will be specifically for high power
    beams is included. The wall current monitor is a critical piece of
    instrumentation used to understand the longitudinal beam
    characteristics. Additionally, for observing beam instabilities
    associated with high intensity protons, a higher frequency (higher
    bandwidth, up to 1 GHz) wall current monitor is required. Not doing
    this work may adversely affect RHIC or NASA operations, and it will
    impact our ability to diagnose high intensity phenomena.

3)  The AGS IPM gas-leak servo-controls need to be moved to a location
    that has lower radiation.

4)  Motion controls for flags and movable devices in the AGS ring are
    old and need to be replaced. This includes very old controls for the
    motors. Not doing this work will not affect RHIC or NASA operations.
    It will seriously affect RSVP.

5)  There are 4 flags in the AGS needed for RSVP which will require
    cameras that can take the high radiation environment. Not doing this
    work will not affect RHIC or NASA operations. It will adversely
    affect RSVP.

6)  Repair/replacement of radiation damaged or old cables. If this work
    is not done then there is much greater risk that further activation
    during high intensity operations will accelerate failure rates in
    the cables. Damaged cables pose the risk of fire and electrocution.

7)  AGS Ring grounds monitoring system upgrade. Not doing this work will
    not affect RHIC or NASA operations. It will seriously affect RSVP.

### Controls

> The following controls items must be addressed to ensure maintainable
> delivery of high intensity protons:

1)  Standard VME interfaces will be provided for the instrumentation
    systems listed in ***3.2.5*** (items 1, 2, 4, 5, 7). The existing
    legacy controls interfaces are un-maintainable.

2)  Standard VME power supply interfaces will be provided for the H20,
    F5, and F10 septa, the J10 Dump Bump and active filter power
    supplies, replacing un-maintainable legacy interfaces.

3)  Software and database engineering will be needed for both new
    front-end interfaces and console level applications that must be
    modified to connect with them.

> Not doing this work will adversely affect RSVP operations, since
> maintaining legacy controls hardware that have unpredictable failure
> modes and poor documentation is extremely difficult.

### Modifications for MECO

> Prior to the AGS RSVP project office, modifications of the Booster and
> AGS for MECO appeared in the MECO WBS. These items have been moved
> into the Booster AGS WBS structure. There are two components to the
> MECO modifications. First a vertical AC dipole which can operate in CW
> mode and provide enough kick to displace the entire beam in the
> accelerator outside of the vacuum chamber. Second is a set of
> stripe-line kickers and associated electronics and power amplifiers
> that are capable of negating the kick of the AC-dipole for the high
> intensity bunches. The purpose of these two systems working together
> is to ensure a high degree of intra-bunch extinction. These two
> systems are critical for the successful operation of the MECO
> experiment.

### Modifications for KOPIO

> Prior to the AGS RSVP project office, modifications of the Booster and
> AGS for KOPIO appeared in the KOPIO WBS. These items have been moved
> into the Booster AGS WBS structure. There are three components to the
> KOPIO modifications. In addition, two of these components are being
> co-funded by the Canadian collaboration (TRIUMF). The three systems
> are an upgrade to the AGS injection kicker's subsystems, a new 25 MHz
> RF cavity, and a new 100 MHz RF cavity. The upgrade to the injection
> kickers will permit higher injection momentum and permit for higher
> beam intensities for KOPIO. The new 25 MHz RF cavity is used to
> generate the micro-bunch structure in the slow extracted beam to
> KOPIO. The 100 MHz RF cavity allows making even shorter bunches in the
> micro-bunch structure. These three systems are critical for the
> successful operation of the KOPIO experiment.

### Development of Beams

> Both RSVP experiments have demanding requirements and a program to
> meet these requirements has been developed. A series of beam tests and
> studies will be performed during the construction phase of the two
> experiments, allowing the parameters for the operation of these
> experiments to be explored. These studies are critical to the
> successful operation of both experiments, since results of these
> studies will affect the design of a number of critical components.

## AGS Switchyard

> The existing AGS Switchyard was designed and built over 25 years ago.
> Its purpose was to service many experiments simultaneously. Since the
> AGS was capable of providing more beam per cycle than any single
> experiment was capable of accepting, it was a very cost effective
> method of operation. The existing switchyard was designed at a time
> when the peak AGS intensity was below 10^13^ protons per cycle and
> beam was injected into the AGS directly from the LINAC. Nevertheless
> it has operated very well in the post-Booster era and beam intensities
> in excess of 7x10^13^ have been delivered. The key feature of
> operation of the Switchyard is the splitting of beams. The operation
> of RSVP does not require split beams. The acceptance of the beam
> splitters is not sufficient to allow an un-split beam transport,
> without beam losses on the beam splitters. This is especially true for
> MECO, which operates at lower energy, and thus with a larger beam. A
> new Switchyard is being proposed, in which all beam splits are
> removed.
>
> MECO will be situated in the A-line (8 GeV/c beam).
>
> K0PI0 will be situated in the B-line (25.5 GeV/c beam).
>
> The possibility of running E949 (C-line) during RSVP construction will
> be accommodated but will require a new beam dump (this is part of the
> E949 budget request) and completion of the switchyard work to the
> point where work outside the switchyard can proceed while E949 runs.
>
> The AGS NASA Radiobiology experiment (A3 beam) will be relocated.
>
> The RHIC e-cooling R&D project will be situated in the North East
> Building Addition (C1/C5 beam area)
>
> The D-line will be decommissioned.
>
> No other Slow Beam experiments (including test beams) will be
> accommodated at this time.
>
> Beam will be delivered to only one experiment at a time (no beam
> splits).
>
> The changes outlined below are contingent upon being able to afford
> the costs within the RSVP construction budget.
>
> **[Planned changes to the AGS beam switchyard follow:]{.underline}**
>
> The present switchyard design incorporates 3 electrostatic beam
> splitters with motion controls, three thin Lambertson magnets with
> motion controls, several thick Lambertson magnets, skew quads, tilted
> dipoles, lots of beam instrumentation, ramped dipoles, beam servo
> dipoles etc. All this allows the AGS beam to be split into up to 4
> beam lines, something not needed by the RSVP experiments (MECO or
> K0PI0 run as an \"OR\"). We propose to simplify the switchyard to
> allow only one beam line at a time. Simple dipole magnet switches will
> be used to select the appropriate beam line. All splitters,
> Lambertsons, servos, ramps, skew quads etc will be removed as well as
> the vertical pitching presently needed to thread the beams through
> Lambertson apertures.
>
> Beam optics for RSVP primary proton transports will be employed that
> present near zero dispersion (position and angle) beams to the
> respective target stations, thereby avoiding the need for servo-SWICS
> and ramped dipoles in the beams. Preliminary optics designs for both
> experiments have been generated that are consistent with this.
>
> Costs to do this have been developed. ***The present strategy calls
> for the D-line to be decommissioned***. This will make available
> shielding, transport magnets and additional floor space for the RSVP
> experiments and should help offset the costs.
>
> The D-line could be preserved as an \"OR\" with other beams at a cost
> to be determined - our first priority is to make use of D-line
> components and shielding for RSVP, then to see what it\'ll take to
> preserve the D-line for possible future RSVP tests or dedicated
> experiments that make use of this beam.
>
> The plan is to install a beam plug downstream of the 4 quads (CQ1-4)
> that bring the beam into the switchyard and configure the shielding so
> that work in the switchyard can be done while RHIC operates with
> either HI or protons. Additional plugs will be installed to allow beam
> to be delivered to the A, B or C-line while work is done in the other
> two. The C-line already has a plug and it appears a plug will not be
> needed for the MECO beam (see below).
>
> Only minimal beam instrumentation in this simplified switchyard is
> needed.
>
> ***[These changes to the switchyard will result in a more robust
> switchyard, minimal activation of components, easier beam tuning and
> lower cost to maintain.]{.underline}***
>
> If this work is not done then losses during RSVP operation will be
> significant, increasing the activation of the switchyard and
> increasing the likelihood of failures. The new switchyard design is
> greatly simplified, making it more robust and reliable. In the very
> least the beam splitters must be removed, to eliminate the current
> limiting apertures. This work has no impact on RHIC operations. It
> does significantly impact RSVP operations, since included in the
> design are provisions for RSVP construction and maintenance during
> RHIC and RSVP operations, which are limited by the current switchyard
> configuration.
>
> **More details of the switchyard simplification plan follow:**

1.  The three electrostatic beam splitters (AB1, DB2 and BB3) and two
    thin Lambertsons (AP1 and CP1) are eliminated along with motion
    controls and associated instrumentation. Eliminate AD4-9 dipole
    string and several misc magnets - pitching magnets, skew quads etc.
    Transport of A, B and C beams is with no vertical pitching with
    horizontal bending magnets used to switch between different beam
    lines.

2.  In order to preserve the D-line transport we could:

> \(a\) replace DB2 with a 6 mr vertical pitching magnet. This is the
> D-line beam switch and directs the beam toward the AD2-3/DD3-4 bending
> magnets.
>
> \(b\) move the thick Lambertsons AD2-3 and DD4-5 up to accommodate the
> D-line beam in the bending aperture.
>
> \(c\) Replace the AD2-3 and DD4-5 bottom yokes with ones that have
> appropriate sized holes to allow the A,B and C-beams to pass
> undeflected.
>
> However, the present plan is to eliminate the D-line altogether to
> free-up shielding etc.
>
> **MECO Specific:**
>
> \(1\) The A-line switch is a new 18C72 dipole (-7.6 deg, AD2) located
> just upstream of the present CD2 location. This dipole bends the beam
> past the I-beam impediment near the AD4-9 A-line dipole string to a
> new 18D36 dipole (-3.7 deg, AD3) that directs the beam out of the
> switchyard.
>
> \(2\) Two new pitching magnets (3x4D24\'s) are placed in the beam line
> between the AD2 and AD3 dipoles to pitch (1.3 deg each - 17.8 meters
> apart) the beam 40 cm above the nominal beam height. This provides the
> necessary clearance below the solenoid magnets and ***should negate
> the need for a MECO beam plug*** since the beam pipe hole through the
> switchyard will not point toward a potential beam/radiation source.
>
> **K0PI0 Specific:**
>
> \(1\) BD4 (un-tilted) or equivalent is the beam switch for the B-line.
>
> \(2\) Needs a beam plug downstream of present BQ10 quad.
>
> **AGS NASA Facility:**
>
> In the event NASA wishes to continue biology experiments using the
> AGS, the facility presently located in the A3 beam line can be moved
> (including the trailer) to the switchyard near the Switchyard East
> Gate.

###  Design

> The new switchyard is a preliminary design and detailed design of the
> beam line elements, shielding, vacuum, services, instrumentation, and
> controls needs to be done. New drawings and documentation need to be
> produced.

###  Shielding

> Shielding modifications are kept to a minimum, since the existing
> shielding is basically in the correct configuration. The major changes
> are in the shielding between the AGS and the switchyard, which will be
> modified to allow access to the switchyard and beam line areas during
> RHIC or polarized proton operations. The shielding interfaces to the A
> line (for MECO) and B line (for KOPIO) will be modified to accommodate
> the new design and to allow access to those areas when one or the
> other is in operation.

###  Vacuum

> The new switchyard design does not require as many vacuum interfaces,
> allowing for improved vacuum without significant upgrade of the vacuum
> system infrastructure. Many flanges could be welded, eliminating many
> vacuum failure points. The vacuum around the MECO RF modulated magnet
> needs to be better than the rest of the switchyard. The interfaces for
> this section will be thin windows.

###  Electrical

> The power requirements for the new switchyard are reduced, since the
> number of elements is reduced. The number of power supplies is
> reduced. Power distributions will need to be adjusted, since the load
> distribution is changed, but this is a minimal alteration.

###  Mechanical

> All moveable magnets are eliminated. Most magnets are recycled
> elements, so no new designs are required, with the possible exception
> of the BD4 replacement. This thick Lambertson magnet is required to
> permit beam to pass through to C target or be bent into B line to
> KOPIO.
>
> Collimators to be included are a first stage collimator in the
> upstream switchyard, and secondary collimators in the beam lines. The
> main purpose of the collimators is to remove large amplitude particles
> and beam halo.

###  Instrumentation

> The switchyard has historically been instrumented with flags, since
> this is the best method of observing the split beams (on a phosphor
> screen). But without split beams flags, which require video and more
> complex data acquisition systems, are no longer required. Nevertheless
> the infrastructure for flags exists and so in some locations costs can
> be kept to a minimum by leaving the flag instrumentation. There is
> also a large set of existing beam loss monitors, which can be reduced
> to less than half the existing set. Some repair and upgrade of this
> system is required, to be in proper condition for long term RSVP
> operation, but for the most part does not require significant redesign
> or modification. Since most flags will be eliminated, some locations
> will have new profile monitors, either segmented wire ion chambers
> (SWIC), or external profile monitors (EPM). Only a small number of
> these are required. There is a strong push towards minimizing all
> plunging instrumentation. This permits non-destructive beam
> measurements and simplifies the mechanical operation.

###  Controls

> The following controls items must be addressed to ensure maintainable
> delivery of high intensity protons:

1)  Standard VME interfaces will be provided for the instrumentation
    systems listed in ***3.3.6***.

2)  Standard VME power supply interfaces will be provided for the
    beam-line magnets to replace the 25-30 year-old Datacon hardware
    that has become un-maintainable.

3)  Software and database engineering will be needed for both new
    front-end interfaces and console level applications that must be
    modified to connect with them.

###  Conventional Infrastructure

> Existing buildings and services will support the new systems. New
> controls and instrumentation electronics will be located in an air
> conditioned trailer inside the main experimental area building.

## Safety and Environmental Protection

###  Access Controls

> The access control safety system (PASS) for the switchyard and the
> beam lines will use networked Programmable Logic Controllers \[PLC\].
> In order to provide the required dual independent protection the area
> served by PASS has two independent PLC's \[field machines\]. These
> field machines are separately networked \[DH+\] into 2 divisions \[A
> and B\]. Each division independently provides full protection. All the
> I/O's (gate switches, critical devices, etc.) are redundantly
> monitored by both PLC systems.
>
> The MCR operator interface utilizes touch screen displays \[flat
> panels\] on a command network that is connected through firewall
> machines to the separate divisions.

# Summary

> We have listed the work that we believe is required in order to ensure
> the success of the two RSVP experiments, MECO and KOPIO. Occupational
> dose to workers, minimization of environmental impact, reducing the
> risk of equipment failure, reducing the risk of fire and minimizing
> the impact on other experimental programs being performed at C-AD were
> all considerations in forming this list. Achieving the best
> performance for RSVP based on known experimental requirements was a
> foremost consideration, but this must also be balanced with many other
> considerations. We believe this list is complete and all of the items
> in this list are technically achievable.

# References

## C-AD AGS RSVP Project Office web site: <http://server.cad.bnl.gov/esfd/RSVP/RSVP_AGS_WBS.htm>

## BNL SBMS Subject Area: Accelerator Safety, Design Practice for Known Beam-Loss Locations, Effective Date: September 2000 ([[https://sbms.bnl.gov/standard/1r/1r09e011.htm]{.underline}](https://sbms.bnl.gov/standard/1r/1r09e011.htm))