ATF2 OverviewFinal Focus Test Facility at ATF

presented by T. Tauchi,ILC-Asia WG4: Beam Delivery

at ATF2 mini-workshop, SLAC

5 January, 2005

Final Focus system (36.6m)

10m N

PLC Test Facility

ATF – DR

ATF – EXTATF2

Final GoalEnsure collisions between nanometer beams;

i.e. luminosity for ILC experiment

FACILITYconstruction, first result

ATF2/KEK2005-07-07?

FFTB/SLAC1991-93-94

OpticsPantaleo's local choromaticity

correction scheme; very short and longer L*

(β*y=100μm, Ltot=36.6m)

Oide's conventional (separate) scheme; non-local and

dedicated CCS at upstream; high symmetry; i.e. orthogonal tuning (β*y=100μm,, Ltot=185m)

Design beam size

37nm / 3.4μm, aspect=92(γεy=3 x 10-8 m)

60nm / 1.92μm, aspect=32(γεy=2 x 10-6 m)

Achieved ? 70nm ( beam jitter remains !)

Reduction of Risk at ILC

parameter symbol unit ATF2 CTF3New Line B

SPPS LCLS

energy E GeV 1.54 0.2-0.4 30 14bunch

population N 1010 1 0.6-3 2 0.6

emittance γεx/γεy μm 3/0.03 1-4 50/5 1/1

E spread (rms) σE/E % < 0.1 0.1-0.35 1.5 < 0.1

bunch length σZ μm 8,000 300 12-40 20IP beta function β*x/β*y mm 10/0.1 50/0.1 4/0.1 4/0.1

IP beam size σ*x/σ*y μm 3.4/

0.037 1.5-0.2 4.5/0.16

0.45/0.070

Possible FF Test Facilities

Mode-I A. Achievement of 37nm beam size A1) Demonstration of a new compact final focus system; proposed by P.Raimondi and A.Seryi in 2000, A2) Maintenance of the small beam size (several hours at the FFTB/SLAC)

Mode-II B. Control of the beam position B1) Demonstration of beam orbit stabilization with nano-meter precision at IP. (The beam jitter at FFTB/SLAC was about 20nm.) B2) Establishment of beam jitter controlling technique at nano-meter level with ILC-like beam (2008 -?)

ATF2 OperationThe mode-I and -II can not go together for BSM and IP-BPM at the same FP.

First, ATF2 will operate in the mode-I with the BSM.

Next, ATF2 will operate in the mode-II with the IP-BPM.

In long term, ATF2 will interchangeably operate the mode-I and -II.

RequirementsMode ATF-EXT ATF2

IJitter < 30% of σy

γεy=(4.5 3) x 10-8m

BSM (laser in higher mode)BPMs with 100nm res. at QsPower supplies of < 10-5

Active mover of Final Q

II Jitter < 5% of σy

( 2nm jitter at FP )

BPM with < 2nm res. at FP

Intra-bunch feedback forILC style beam

Mode-I

SF1 SD1 SF2 SD2

QF QDQF

S. KurodaKuroda Optics (L*=2m, Ltot=36.6m)

FP

E=1.54GeVγεx=3x10

-6mεx/εy=100/1δ=0.1%

Geometric aberration cancellationChromaticity correction

0.8

1

1.2

1.4

1.6

1.8

2

2.2

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

Beam Size vs Emittance

sigx/sigx0sigy/sigy0sigx/sigx0(NORAD)sigy/sigy0(NORAD)

sig/

sig0

emit/emit0

sig0=Sqrt[beta emit]emit0=1e-9m(for x) 1e-11m(for y)

0.8

1

1.2

1.4

1.6

1.8

2

2.2

0 0.0005 0.001 0.0015

Beam Size vs Momentum Spread

sigx/sigx0sigy/sigy0

sig/

sig0

Momentum Spread

Emittance is fixed as emit0

• Tracking with 1000 particles• εx=1e-9 m, εy=1e-11 m δ=0.1% @entrance• →σ x =3.76µm σ y =35.9nm @IP

Performances

ATF2

-50000-40000-30000-20000-10000

01000020000300004000050000

Element

X Chromaticity Y Chromaticity

GLC

-80000

-60000

-40000

-20000

0

20000

40000

60000

Element

X Chromaticity Y Chromaticity

Local Chromaticity Correction

SLAC-LLNL 3 Cavity BPM systemfor nm resolution study

LLNL Design rigid support andnm mover,SLAC Improved electronics,BINP Design BPM

Achieved resolution 50nmPreliminary result shows 16nm in Nov.29-Dec.17, 2004

measured by the cavity BPM, May 2003, M. Ross

The present jitter is less than 30% σy , i.e. ~2um, if slow component can be removed.

Mode-II

Beam jitter at FFTB/SLACT. Shintake et.al. , LINAC98

!"!!=#

140 nm at these BPMs. This set of BPMs is used for the

resolution measurement, as well as for characterizing the

beam’s jitter parameters before entering the final

transformer.

2 EXPERIMENT CONFIGURATION

The RF-BPMs are a typical pill box cavity design

producing a signal containing four components

(1)

where q is the beam charge, y is the beam’s offset with

respect to the center of the cavity, y’ is the beam’s angle

with respect to the cavity (y’=dy/dz), y0 is an offset

which comes from the TM010

signal (common mode), and

j denotes the imaginary terms.

The signals from the RF-BPM are sent through a 180o

hybrid that significantly reduces the second and third

term in equation 1. The difference signal from the

hybrid is passed into a RF receiver circuit. The RF

receiver circuit is set up as a heterodyne synchronous

detector that extracts the amplitude and polarity of the

BPM signal. The beam induced waveform is filtered at

5712 MHz and mixed down to 500 MHz. The 500 MHz

signal is then filtered, amplified, and mixed down to 50

MHz. This signal is again filtered and amplified and

passed to a dual track and hold (NiTNH) module, a 16

bit digitizer with a ±2 volt limit and a 300 MHz

bandwidth. The digital signal is converted into beam

position and read by the SLC Control Program (SCP).

The measured dynamic range of the receiver is 51

dBm with measured noise of -82 dBm or 1 nm for a

beam charge of 1 nC. The gain factor for the system is

measured by moving the BPMs with respect to the beam

(see section 3 below for this process).

3 DATA ACQUISITION

Before being used for data acquisition, the RF-BPMs

were phased to the electron beam and a signal to

position calibration constant was measured. Phasing was

accomplished by using a fourth cavity which is located

at the end of the triplet stack (see figure 1). Since the

BPMs were phased to the beam, drifting due to timing

signals were eliminated. The calibration constant was

measured by moving the BPMs with respect to the beam.

Calibrated linear variable differential transformers

(LVDTs) measured the change in the BPM’s position

while the change in the BPM’s signal is recorded. Within

the dynamic range of the receiver, position verses signal

is linear and the slope is the gain or calibration constant.

This calibration constant is stored in the SCP’s database

for use with the BPM acquisition software. The

maximum beam rate of the FFTB is 30 Hz. The signals

from RF-BPMs are acquired simultaneously with the

signals from standard BPMs up to the acquisition rate of

30 Hz. This allows for the comparison of the beam

positions measured by the RF-BPMs to that measured by

the standard BPMs.

4 DATA ANALYSIS

The top plot in figure 2 displays beam trajectories for

approximately 300 machine pulses at an acquisition rate

of 30 Hz. The beam’s waist at the IMFP is close to the

middle RF-BPM of the triplet set. With only drift spaces

between the BPMs, the calculation of the slope and

offset for each beam trajectory at the center BPM does

not require knowledge of beam line optics. The bottom

plot in figure 2 shows angles verses positions with a one

sigma ellipse. This is a measurement of the jitter

emittance which is equal to 1.533 µm. The equation for

the emittance is

(2)

where y is the measured position at the center BPM, y’ is

the measured angle using all three BPMs (y’=dy/dz), and

<…> means an average over a series of measurements

with a fixed time limit. The jitter emittance is close to

one tenth of the beam emittance, which is expected for

the observed beam jitter to beam size fraction of 30% in

the SLC. This is an important measurement because it

shows that the RF-BPMs agree with standard BPMs.

+++=

!0.05 0 0.05

!2

!1

0

1

2$

y(µ

m)

$z(m)

%jitter

& 130 (nm)

!0.3 !0.2 !0.1 0 0.1 0.2 0.3

!40

!20

0

20

40

yp

(µra

d)

y(µm)

#jitter

& 1.533 (um)

Figure 2. The top plot displays the measured beamtrajectories. The bottom plot shows the calculatedjitter emittance.

912

With the demagnification of 7, σjitter is about 20nm at IP,

where, the jitter contributed 30% in the beam spot size.

300 pulses at 30Hz

3 RF BPMs are installed at an image focal point.

σRF-BPM = 25nm

σRF-BPM = 80nm at IP, σθ=460μrad

Jitter Control for 5% σy

nm Fast Feedback Double kicker X jitter compensation

µm Feedforward( DR BPM -> EXT Line new stripline kicker)

proposed by H. Hayano

Intra-bunch

ML13X

BPM26

0.03 0.032 0.034 0.036 0.038 0.04 0.0420.11

0.115

0.12

0.125

0.13

0.135

0.14

0.145

0.15

0.155

0.16

BPM26LW (RING)

ML13X

(E

xt Lin

e)

G.White and FONT3 group, 13 December 2004Jitter correlation between DR and EXT

vertical jitters 20 bunches/train40 trains at 1.6Hz

KEK 3-Cavity BPM system for nm resolution study

KEK Design nm mover and nm position feedback,KEK design BPM and electronics

6.5GHz cavity BPM.Sensor cavity and reference cavity are in one body.Symmetric signal extraction.

3 BPMs on nm mover,BPM Y positions are locked by laser interference position monitor and piezo actuator feedback.

System is under beam test now

Goal < 2nm

0

0.35nm rms

feedback on

200100

time (sec)0

80

60

40

positio

n (

nm

)

Performance of nm Mover

Novel IP-BPM R&DPosition resolution of less than 2nm under the large beam divergence of 300μrad

and the bunch length of 8mm.V. Vogel proposed at the 2nd Mini-Workshop on Nano Project at ATF, 11-12, Dec. 2004

Triplet of Cavity-BPMs 1st Cavity: Y position at FP 2nd Cavity: X position at 5cm from FP both with damped Q for common modes 3rd Cavity: very small gap of 0.5-1mm for angle and tilt measurements

中２階

１階作業ルーム 中２階

１階作業エリア1階部分共有

7500

2500

配管

1階部分のみ X- bandで使用

RF Gun

Pump Room

Shutter

PitPit

BendingMagnetPowerSource

Clean Room

Klystron Modulator

Laser

S-band Linac

Damped

714MHz RF sour

Laser Wi

Clearance forShielding

EXIT

road lock

S- Band KLY

RF-Gun Laser0 5 10

Scale Unit:m

N

10m

Floor tilt comparison

10µrad10µrad

ATF beam line ATF2

4µrad

14 degree!KEKB tunnel floor

temp

tilt

ATF floor tilt, similar to KEKB tunnel floor

KEKB tunnel tilt measurementsKEK preprint 03-97

M.Masuzawa, 2nd mini-workshop on nano project at ATF,

11 Dec.2004

Tolerance of 8μrad for Bend at ATF2. (Kuroda)[ 10% beam size growth ]

8μrad

8μrad

Comparison between ATF (Jpower meas. Feb.) & ATF2 (Dec.)

Red : ATF2Blue : ATFDiffference in vertical direction is largest.!agrees with Yamaoka’s measurememt.

Fair comparison??“Noiser” around ATF2 (chiller pumpsnear by, other activities going on, etc.)Taken on different days.

Day-to-day fluctuations in ATF2 area? !

X Y

V

~13Hz

~25Hz

M.Masuzawa, 2nd mini-workshop on nano project at ATF,

11 Dec.2004

Vertical

40nm (beam spot size)

2nm at Final-Q (Δy*=4nm)

5 nm (beam size)

0.1 1 10Hz

Amplitude of GM

Final-Q must be stabilized!Also, IP-BPM!

“ATF2 floor”

ATF-EXT floor

Comparison between ATF (Jpower meas. Feb.) & ATF2 (Dec.)

Red : ATF2Blue : ATFDiffference in vertical direction is largest.!agrees with Yamaoka’s measurememt.

Fair comparison??“Noiser” around ATF2 (chiller pumpsnear by, other activities going on, etc.)Taken on different days.

Day-to-day fluctuations in ATF2 area? !

X Y

V

~13Hz

~25Hz

M.Masuzawa, 2nd mini-workshop on nano project at ATF,

11 Dec.2004

orthogonal to beam line

100nm for Δx*=0.4μm

10nm

0.1 1 10Hz

Amplitude of GM

1nm

1μm

FFTB/ATF thick width length area cost/area cost

unit m m m m2 yen/m2 yen

floor 1 7.2 56 403.2 126,960 51,190,078

shield thick x 2 height length volume cost/volume cost

unit m m m m3 yen/m3 yen

concrete 2 3 56 336 20,000 6,720,000

concrete 2 3 5.2 31.2 20,000 624,000

total - - - 367.2 20,000 7,344,000

Cost Estimation : FF facility

magnet number cost/unit cost (yen)QA 8 1,200,000 9,600,000QB 8 1,200,000 9,600,000

QC1 2 2,500,000 5,000,000QC2 2 2,500,000 5,000,000BH 2 2,500,000 5,000,000

SEXT 4 1,200,000 4,800,000Power supply 26 1,500,000 39,000,000

Support 26 1,000,000 26,000,000Cable 0 0 0

cavity-BPM 20 2,300,000 46,000,000streak camera 0 0 0

laser wire 5 7,000,000 35,000,000wire scanner 0 0 0

laser interferometer 1 10,000,000 10,000,000

vacuum chamber,pump 36.6 300,000 10,980,000

labor for setup 36.6 70,000 2,562,000

Total - - 208,542,000

Cost Estimation : FF components

Schedule2002 optics design (Local correction, S.Kuroda)2005.3 “international” proposal with ILC-WG42005.4 construction starts2007.3 completion2007.4-6 achievement of σy*=37nm- 2008 nanometer stabilization of final quadrupole2009-α PLC test facility strong QED experiments

SLAC-FFTB schedule1989 optics design (Oide)1991.3 proposal (CDR)1993 summer completed1994 spring 70nm1995 RF-BPM1997 E144:collision with laser (non-linear QED)

KEK Nano-BPM

ProposalDesign

ATF21st beam

2005 1 2 3 4 5 6 7 8 9 10 11 12

2006 1 2 3 4 5 6 7 8 9 10 11 12

2007 1 2 3 4 5 6 7 8 9 10 11 12

Summershutdown

Summershutdown

ins. 300ns kicker

50nm 25nmcable

2 nmsmall band w.

FONT3

SLAC/LLNL Nano-BPM

FONT4?digital

3 bunches with sB= 150 ns

Jitter control: Feedforward from DR to EXT

nm feedback system based on KEK and SLAC/LLNL NanoBPMs

25nm

Novel IP-BPM R&D, bunch length dep., damped Q, small gap

Jitter study

ATF2

ATF2 Mode- I, -II ?TDR

2nm

Power SupplySupport Tables

Floor

Magnets

Instrumentation (BSM, BPMs, laserwire, feedback....)

Install-ation

Vacuum pipes, pump

Alignment system

Control system

ProposalDesign 1st beam

2005 1 2 3 4 5 6 7 8 9 10 11 12

2006 1 2 3 4 5 6 7 8 9 10 11 12

2007 1 2 3 4 5 6 7 8 9 10 11 12

Summershutdown

Summershutdown

Summershutdown

TDR

Shield

First investigations of

ATF2 at SLAC

Axel Brachmann, Thomas Himel, Tom Markiewicz, Janice Nelson, ToshiyukiOkugi, Mauro Pivi, Tor Raubenheimer, Marc Ross, Robert Ruland, Andrei Seryi,

Peter Tenenbaum, Mark Woodley, Mike Woods

December 11, 2004

2

Content and plans! Design and study of various optics versions

" Toshiyuki Okugi, Mauro Pivi, Tor Raubenheimer, Andrei Seryi

! Extraction line correction and orthogonal knobs

" Peter Tenenbaum, Mark Woodley

! Also working on (to be discussed on January 5) :

! How to quantify risk reduction

" Tom Himel

! ILC train extraction options

" Janice Nelson, Tom Markiewicz, Marc Ross, Mark Woodley

! Application of Shintake style beam size monitor

" Axel Brachmann, Mike Woods

! ATF2 alignment

" Robert Ruland

First Investigations of the ATF2

optics from the UK

Deepa Angal-Kalinin

James Jones

Daresbury Laboratory, UK

11th December, 2004

2

! First discussions to participate in the ATF2 Final

focus tests : at the ILCWS-WG4, KEK.

! Study of various optics versions:

! Extraction line + FF : S. Kuroda

! Extraction line + FF : NLC like FF

! MAD decks from obtained from SLAC

! Reproduced optics results with MAD, BETA

(J.Payet, Saclay)

! Tracking using DIMAD, TRACY2

! Preliminary investigations of the tolerances for

these two optics versions

Author List is Open.So, please

Join us !

Contributed paper to PAC05, Knoxville, Tennessee, 16-20 May,2005

PROPOSAL OF THE NEXT INCARNATION OF ACCELERATOR TEST

FACILITY AT KEK FOR THE INTERNATIONAL LINEAR COLLIDER

H.Hayano, Y.Higashi, Y.Honda, Y.Iwashita, M.Kuriki, S.Kuroda, K.Kubo, M.Kumada,

M.Masuzawa, T.Mihara, T.Okugi, T.Sanuki, R.Sugahara, T.Takahashi, T.Tauchi, J.Urakawa V.Vogel,

H.Yamaoka, K.Yokoya Univ.Tokyo/Kyoto/NIRS/KEK, Japan

I.Agapov, D.Angal-Kalinin, R.Appleby, G.A.Blair, S.Boogert, P.N.Burrows, J.Carter, G.Christian,

N. Delerue, C.Driouichi, J.Jones, A.Kalinin, S.Malton, S.Molloy, A.Reichold, D.Urner, G.White,

CCLRC/Oxford/ QMUL/RHUL/UCL, UK

P.Bambade, O.Napoly, J.Payet, Saclay/Orsay, France

H.Brauu, D.Schulte, F.Zimmermann, CERN, Switzerland

N.Names, DESY, Germany

B.Grishanov, F.Podgorny, V.Telnov, BINP, Russia

A.Brachmann, J.Gronberg, T.Himel, T.Markiewicz, J.Nelson, M.Pivi, T.Raubenheimer, M.Ross,

A.Seryi, C.Spencer, P.Tenenbaum, E.Torrence, M.Woodley, M.Woods, Univ.Oregon/LLNL/SLAC,

USA

Abstract

The realization of the International Linear Collider (ILC) will require the ability to create and reliably maintain

nanometer size beams. The ATF damping ring is the unique facility where ILC emittancies are possible. In this paper we

present and evaluate the proposal to create a final focus facility at the ATF which, using compact final focus optics and

an ILC-like bunch train, would be capable of achieving 35nm beam size. Such a facility would enable the development

of beam diagnostics and tuning methods, as well as the training of young accelerator physicists.