1 brookhaven science associates accelerator systems overview f. willeke 4 th accelerator scientific...

1 BROOKHAVEN SCIENCE ASSOCIATES

Accelerator Systems Overview

F. Willeke

4th Accelerator Scientific Advisory Committee Meeting

July 17-18, 2008


Overview

• Introduction• Lattice and Accelerator Physics• Magnet Design and Prototype Production• Support systems and Alignment• Instrumentation• RF• Controls


NSLS-II Accelerator Design Goals

Beam Energy:

Quasi constant, high Beam Current:

Small Radiation Source Size:

- horizontal Beam Emittance: - vertical Beam

Emittance:

Moderate Beam Energy Spread:

High Orbital Stability:

Large Space for Insertion Devices:

E = 3 GeV

I = 500 mA, I / I = 1%

x = 0.6 nm

y = ~ 8 pm (diffraction limited @12keV)

E / E = 0.1% (RMS)

z, z’ = 10% · z,z’

LID = 226 m (28.5%),

with bending magnet sources included space for at least 58 beam lines


… Achieved by the following design features WBS 1.03

• Large circumference C = 792 m

• Large number of achromats N = 30

• Robust double bend

achromatic optics b = 2nm @ 2 x (theoretical minimum)

• Low bend field B = 0.4 T low radiation loss U0=286kV

• Damping wigglers for

small emittance = 0 × U0 / ( U0+Uw )

• Top-Off Injection

• On-Energy Injection


NSLS-II Accelerator Overview

Large storage ring C = 792m with 30 double bend achromats

30 straight sections

- 15 long (9.3m) - 15 short (6.6m) Straight

Including:

1 injection (long) straight

2 RF (long) straights with

2 sc single cell 500 MHz cavities

1.5 GHz passive s.c cavity . for bunch lengthening

3 (baseline)- 8(full scope) damping wiggler straights, 2x3.5m 1.8T Damping Wigglers each

Injector: Compact booster synchrotron

fed by a 200MeV S-band linac

Storage Ring:

30 DBA Cells


Response to Last MACResponse: The horizontal space in the tunnel is considered not sufficient to provide a fully variable gap damping wiggler. Other means are explored: - Dedicated tuning wiggler - Alternative means of beam control

Variable Gap Wiggler:

Few Longer Straights Response: We are working towards a decision in Spring 09 whether to go with a fully symmetric lattice or with a reduced symmetry lattice, first results are available alreadyLimited Dynamic Aperture with IDs

Response: This is a focus of the FY08/09 accelerator physics activities

Alternative Wiggler DesignsResponse:The wiggler design is based on straight magnet


General Status

• NSLS-II Accelerator systems made steady progress since the last ASAC meeting.

• FY08 started with a 3 Mio $ funding deferral of PED funds into FY09

• Parts of the R&D program (permanent magnet laboratory development and LINAC frontend studies) delayed

• R&D program has concentrated on areas where designs need to be finished: magnets and support structure, alignment and stability

• Design has advanced in areas where production needs to start in 2009 in order to be able to start installation in 2011:

Magnets, support systems, vacuum system, any area which interfaces with the building and conventional system: electrical and mechanical utilities, cryogenic system, RF

• The important next goal is to get CD-3 approval in order to be able to start constructing the ring building


Design Maturity Goal for CD-3


Interface to CF

• Layout of electrical systems in building performed and AC distribution system defined

• Distribution of Electronic Racks on Tunnel Mezzanine laid out, design and location of cable conduits performed and defined

• Detailed NSLS-II cable plans for all subsystems produced

• Chilled and process water system architecture revised

• Result is a more centralized system with less components, less space requirements and more maintenance friendliness

• Interface of RF and CF defined

• Interface Injector and CF defined ACCELERATOR – CIVIL CONSTRUCTION INTERFACE WELL DEFINED BY NOW

ACCELERATOR – CIVIL CONSTRUCTION INTERFACE WELL DEFINED BY NOW


Accelerator Physics

• Lattice design stable since January• Orbit correction scheme revised, dynamic orbit correction schemes developed• Decker distortions and canting of wigglers integrated in lattice• Feasibility of extra-long straight evaluated• Dynamic aperture analysis is continuing• Field quality of the magnet system defined based on thorough analysis of the nonlinear dynamics performed• Systematic impedance assessment of components of the vacuum system in progress• Integration of damping wigglers: work in progress


Dynamic Aperture with Multipole Errors

Introduction of high precision Q+S magnets in center of achromat

DA small @ -3% p/p Systematically studied, well understood


Top Off Safety Study

8.84mm, half aperture

13.54mm, half aperture

MIDPOINT OF LONG STRAIGHT

-10 -5 0 5 10 15 20-60

-40

-20

0

20

40

60

37

38

Stick Absorber38

23

75

112

-10 -5 0 5 10 15 20-50

0

50

100

150

200

250

Safety ShutterFixed Mask

Goal: Need to understand what limiting apertures and additional measures have to be

Started to model accelerator components with/without magnetic field defect

Collaborations with LBL, SLAC

LBL top off back tracking code

Sweeper magnet


Progress with NSLS-II Magnet Systems• Reference Design of NSLS-II quadrupole and sextupole

magnets refined and completed TIGHT FIELD TOLERANCE SPECIFICATIONS MET

• Contracts for 9 prototype dipoles, quadrupole and sextupole, magnets awarded to three vendors

• Short Prototype Dipole magnet (35mm gap, 1m long) received, measurement program started

• Tests on dynamic dipole corrector magnets performed, design improved based on tests

• Study of 10-pole correctors performed

• Cost estimate of magnet system updated based on 2008, vendor quotes (eight interested vendors)

• Girders redesigned for 1.2m beam height

• Vibration tests performed on test girder

• Alignment procedure refined and demonstrated


Magnet Types in a Cell

Wide Quadrupoles & Sextupoles to accommodate X-ray transport.

Regular Quadrupoles &Sextupoles

Correctors

Dipoles

Six types of quadrupoles

Three types of sextupoles

Two types of dipoles

2 types of correctors


Support system

Floor Plate

Vacuum Chamber

Corrector Magnet

Quadrupole Magnet

Sextupole Magnet

Girder

Re-designed for

1.2m beam height

Vibration studies

Reproducibility after thermal and mechanical cycling tested


Magnet Support R&D


Progress of Vacuum System

• Vacuum chamber design well advanced, prototype chamber in production

• Various prototype chambers from extruded Aluminum received, two vendors qualified to meet NSLS-II requirements

• Machining on short test chambers needed for welding tests ( performed at ANL)

• Shielded bellow designs developed, impedance models generated and evaluated

• Chamber heating and conditioning tests underway, kapton imbedded heater tests successful, alternative method (direct electrical heating) in progress, need of pressurized hot water eliminated

• NEG-support structure developed

• Integration of BPM in progress

• Ozone Cleaning System procured and being assembled


Vacuum System Technical Progress


Injector

ALL THE INTERFACES BETWEEN CIVIL CONSTRUCTION AND INJECTOR WELL DEFINED

(0.2-3) GeV

C= 158m; 1Hz

Booster synchrotron

200MeV S-band Linac 15 nC/s

• Preliminary Design for Turn Key System carried out

• Beam optics flexibility and dynamic aperture study carried out

• Discussed the design with two potential vendors

• Contacts made to 3rd interested vendor for booster turn-key procurement

• Interface between injector and conventional facilities defined

• Beam Transport Line design carried out and iterated with layout of the building and refined


BoosterLattice

Dynamic Aperture

Structure

-30 -20 -10 0 10 20 300

5

10

15

20

25

p/p=-3%p/p=0%p/p=3%

Dynamic aperture

Dipole

physical aperture


Technical Progress: InstrumentationBPM System Emphasized:

•R&D on BPM stability and noise suppression

•IID BPM: Stand with high stability and small thermal expansion

•BPM Button Optimization for maximum resolution

•Button Heating under study

•Study of electronics stability


RFMost important task for RF system was to clarify any interface with the construction of the buildings

RF system still based on the CESR-B type single cell 500 MHz super conducting cavity LLRF system is in the centre of 2008 technical development

• FPGA based control module (cavity tuning, RF phase loop and amplitude loops, ) has been designed PC board has been fabricated, final assembly of the controller is in progress

• Extensive Matlab modeling in progress to optimize the FPGA based tuning and control algorithm needed to satisfy high demands on RF phase stability of 0.5degree driven by external IR beam requirements

• Value engineering on main RF power source underway, goal is to make a decision on klystrons versus combined IOT system by September 09


RF cavity controller


Controller status

• Prototype board being assembled this week• Will test ADC and DAC interfaces, FPGA firmware and allow

measurements of noise floor• MatLAB based system model will directly code FPGA control loops;

Matlab modeling is in development • Designed to meet SR requirements, but will be used for booster,

harmonic cavities by changing firmware, saving on hardware design, controls hardware and GUI interfaces

• Includes a redundant serial communications link specified by controls group - LBL collaboration (uses ethernet hardware without the protocol)


PS System

Fast Corrector Prototype

Open loop performance fast corrector

•Design of power supplies for the main dipole and quadrupole, sextupole, and corrector magnet in progress

•Prototyping of Fast Corrector Supply

•Equipment Enclosures Prototypes being tested

• Detailed layout of cable system including cable conduits / penetrations from mezzanine into tunnel, cable trays, AC distribution

Ongoing tests with corrector magnet prototype


3D Modeling of Power Supply System


Equipment Enclosure Designs

•Air Cooled Racks with chilled water heat exchangers Prototype built and tested


Equipment Enclosures

Prototyping and Testing


Layout of equipment on tunnel mezzanine


Control System

Efforts concentrated on three areas:

• Controls Architecture Development development is the embedded device controller - standard EPICS installed and control system studio a collaborative set of operator

applications being developed at DESY and SNS.

• Relational Database DevelopmentDevelopment/formatting of of configuration tools, scripting tools, web-based reports and machine files

• High Level Application Platform online model running tracy 2 is operational with a lattice derived from an elegant desk As it runs under EPICS all of the channel access clients work on it including the XAL

tools and the matlab middle layer toolkit and SDDS for that matter. open-source protocol (DDS)is examined whether suitable for the high level application

architecture.


Control System Architecture Status

Shared Memory

Ethernet – EPICS Channel Access Protocol

Events/ / Timing Data

Operator stations: Displays, Archiving, Alarm Management, Strip charts, Save/Restore Utility

EVG

CEL L

Timing Master

CPU

EVR

CEL L

BPM IOCs

CPU

EVR

CEL L

PS IOCs

BPM

BPM

BPM

BPM

BPM

BPM

PS

PS

PS

PS

Fast Equipment Protection Signal

CPUStandard EPICS Tools are installed

Control System Studio is being evaluated

Shared Memory Network Prototype

Power Supply Device Interface

LLRF Device Interface

Beam Line Motion Control Prototype


Database Status

Components

Lattice

EPICS Database

Name Mapping

Wiring

Configuration Tools

Component Type

Component

Lattice

EPICS Database

Name Mapping

Wiring

Scripts

Component Type

Component

Lattice

EPICS Database

Web Based Reports

Component Type

Component

Lattice

EPICS Database

Name Mapping

Wiring

Files for control

Lattice

EPICS Database

Name Mapping CompleteComplete FY 08

Complete FY 09

Support expands over project for physics

applications and maintenance support


Lattice

I/O Controller – Tracy 2 SimulationNSLS 2 lattice running

EPICS Client/Server

XAL Tools (not beam based Control)

Matlab Applications

High Level Applications – Client/Sever

The online simulation is running

XAL is installed and running for many operator functions

EPICS tools can look at simulation – including archiver

The NSLS II lattice is loaded as EPICS Channels from script

DDS protocol is being evaluated for use as client/server layer

EPICS Tools )


ORGANIZATION


Accelerator Systems Leads

L. Dalesio L. Doom G. Ganetis C.H..Hseuh E. Johnson S. Krinsky Controls Design Room Electrical Sys. Vacuum Stor. Ring Coord. Acc. Physics

O. Singh J. Rose T. Shaftan S. Sharma T. Tanabe F. Willeke Instrumentation RF Injector Coord. Mech. Syst. Insertion Dev. Div.Dir.


STAFFAccelerator Systems Division Work Force: 56 Staff + ~20 MOU + ~ 5 FTE Temp

80 total workforce @ 60FTE for FY08 (so far)

FY 2008 hires: 17 new scientists and engineers hired

Acc.Physics Group Leader appointed, Injector and Storage Ring Coordinators identified


Accelerator Systems Data Organization

• Systematic Collection of Information• ASD Interface meetings and supporting documentation• RSI Documents • E-discussions (where meetings are not practical)

• Develop standards and conventions• Storage Ring Naming Convention• Nomenclature RSI• Technical Change Request procedure

• Publication of key references and data • Global parameters (includes ASD, CFD and XFD information)• System specific parameters (eg lattice definition)• Interface properties (eg shielding penetrations)•


Value Engineering and Technical Change Control

Formal Procedure of Value Engineering

and Controlled Technical Change• developed, • implemented, and • in use

NSLS-II CCB


Assembly and Workspace Management

Production, Acceptance Test, Assembly and Installation plan generated, NSLS-II Acc. Space requirements updated


Cost Estimate with FY08 $ 3M Budget Deferral for

ACCELERATOR PED Implemented


Accelerator Systems Schedule (as shown at last meeting)

Booster on the critical path

Reason:

• Injector Turn-key procurements delayed to preserve option for alternative vendor development of change of procurement plan as part of the injector risk mitigation strategy

• It also helps to match the time phased cost estimate with the funding profile

After May 2013: Accelerator and ID commissioning


Accelerator Systems Important Schedule Events 2009


Summary

• Overall Good technical progress with NSLS-II accelerator systems design

• The interfaces with the ring building have been clarified in a detailed and comprehensive manner

• Progress in critical R&D activities: alignment, magnet prototyping

• Organizational procedures developed and organization strengthened

• Staffing Plan is in general on track

• Accelerator Systems will be ready for CD-3