Status of DAStatus of DANE2 projectNE2 project

C. BiscariC. Biscari

22th LNF Scientific Committee, Frascati, 29th November 2005

DADANE2 teamNE2 team

D. Alesini, G. Benedetti, M. E. Biagini, R. Boni, M. Boscolo, A. Clozza,

G. Delle Monache, G. Di Pirro, A. Drago, L. Falbo, J. Fox++, A. Gallo, A. Ghigo, S. Guiducci, M. Incurvati, E. Levichev+, C. Ligi, F. Marcellini, G. Mazzitelli,

C. Milardi, S. Nikitin+, L. Pellegrino, P. Piminov+, M. A. Preger,

P. Raimondi, R. Ricci, C. Sanelli, M. Serio, F. Sgamma, D. Shatilov+,

B. Spataro, A. Stecchi, A. Stella, D. Teytelman**, C. Vaccarezza,

M. Vescovi, M.Zobov,

LNF-INFN, Frascati, Italy

+ BINP, Novosibirsk, Russia** SLAC, USA

e+ e- colliderscolliders in the world

PEP II PEP II – shutdown 2008– shutdown 2008

CESR-c CESR-c – shutdown 2007– shutdown 2007

KEK B KEK B – operation until 2008– operation until 2008

SUPER KEKB SUPER KEKB – to be approved– to be approved

VEPP 4M – VEPP 4M – operation since 2000operation since 2000

VEPP2000 – VEPP2000 – first beam 2006first beam 2006

DADANE – operation until 2008NE – operation until 2008Upgrade to be approvedUpgrade to be approved

The only e+ e- collider in Europe

BEPC – BEPC – first beam 2006first beam 2006

Past - Present Future

DADANE upgradeNE upgradeEnergy and Luminosity RangeEnergy and Luminosity Range

Energy @center of mass (GeV) 1.02 2.4

Integrated Luminosity per year (ftbarn-1) 8

Total integrated luminosity > 20 3

Peak luminosity > (cm-1sec-2) 8 1032 1032

K physicsNuclear physicsNucleon form factorsKaonic nucleiLight source

PHYSICS case :afternoon session

IRVacuum chamber

Control systemDiagnostics

Injection kickers

DipolesRadiation shielding

High energy High luminosity

Wigglers Rf systemFeedbackInjection linesCryogenic system

How much we need to modify DANE?

* *4coll

x y

f N NL

N+N-

Increasing of cross section with current due - Beam-beam- Single beam effects (Single bunch effects + Total current effects)Stronger for lower energy

Increasing the luminosity by:Increasing the slope (smaller cross section)Increasing the current Fighting the blowup effects

Higher luminosities

EASIER

Increasing the luminosity by:Increasing the slope (smaller cross section)Fighting the blowup effects

BUTPower = Current x Energy loss

Higher energies Higher Magnetic fields

P (a.u.)

N+N- or L (a.u.)

E = 0.51 GeV

E = 1.2 GeV

Limit in power =Limit in current

4 22 2o dip wigU I E I E

Keep basic DANE design:two rings

flat beams multibunch

high currents

Change: Only one Interaction Region

flexible for all the different experimentsPreferred choice: use of the same detector

Present KLOE IRCoupling compensation:Quadrupole rotation depending on E and/or Bdet

Low beta quads : permanent magnet for fixed energy Mechanical rotation for Detector solenoid compensation

dip

dip

QD+ sol

+ skew

QF+ sol

+ skew

e-

e+

Bdet = 0.2 to 0.4 TB = 1.7 to 4.0 Tm

2.5 m

IR Tunable design

Antisolenoids and skews compensate coupling in the whole range of energies and Bdet

dip

dip

dip

Based on SC technology(Lately developedfor colliders (HERA,BEPC) and ILC)

Double steering to adjust crossing angle

DANE2 quadsGmax = 28 T/m

Brett Parker, Snowmass ILC meeting

IR optical functions

E = 0.51 GeVx* = 1 my* = 1 cmcross = 15 mrad

E = 1.2 GeVx* = 1 my* = 1.5 cmcross = 15 mrad

Parasitic crossing B- B tune shifts

E = 0.51 GeVBunch spacing 60 cm

In the first 2.5 m : 8 pc (every 30 cm)

E = 1.2 GeVBunch spacing 3 mFirst pc after 1.5 m

2

2

2

2

pc e xx

ypc ey

Nr

x

Nr

x

0.051

0.051x

y

0.010

0.012x

y

Tune scans withBEAM – BEAM simulations

in progress to optimize working point

and IP parameters

Synchrotron radiation integrals

2 2

3 3

4 3

22

5 3

1 2

' ' / 2

dsI

dsI

n DI ds

D D DI ds

Emittance - I2, I4, I5Damping time - I2Energy spread - I3, I4Natural bunch length - I3, I4Emitted power - I2

Choice of lattice, dipoles, wigglers

4

232

2

3e

o

r EU I

mc

Damping time and radiation emission

4

232

2

3e

o

r EU I

mc

32

1

x

CE I

C

Energy emitted per turn

Damping time

In DANE now: I2 = 9.5 m-1 , Uo = 9 keV, x = 37 msec

I2 = 4.5 dipoles + 5 wigglers

1.8 T Dipole Magnet, POISSON simulation

DIPOLES

Dipoles per ring 12

B (T) 0.77 – 1.8

(m) 2.22

Gap (cm) 3

Current (A) 150, 430

Choice of normal conducting dipoles

Maximum field: 1.8 T @1.2 GeV

I2 = 2.8 m-1

Wigglers are needed to increase radiation and make beam stronger against instabilities

by decreasing damping time

The contribution to I2 by wigglers is :

In our case:

x (@510 MeV) = 13 msec : I2 = 26 m-1 Lw = 6.5 @ B = 4 T

With same wigglers and scaled dipoles @1.2GeV: x =5 msec I2 = 6.5 m-1

2

2

1

2w w

Bi L

B

Emittance2

52

2 4

55

32 3x

IE

mc mc I I

Dispersion

I5

W W

D D D

Wigglers in dispersive zones increase I5 and emittance depending on and D functions.

Wigglers in non-dispersive zones increase I2 and lower emittance

Wigglers influence beam parameters and dynamics

Change the radiation integrals

Non-linear effects: affect dynamic aperture, lifetime, beam-beam behavior

Wigglers in a non-dispersive zone with low betas for non linear kicks minimisation

+ One Wiggler in a dispersive region for emittance tuning

(as in DANE now for Beam-beam tune shift optimisation)

Good field region centered around wiggler axis

Trajectory centered on wiggler axis, independently of E and B

Trajectory position with respect to wiggler axis, depends on E and B

Usual wiggler design: odd # poles CESRc design: even # poles

E = 0.51 GeV

E = 1.2 GeV

B = 4 T B = 4 T

Choice of wiggler shape

Choice of pole length, w

Once defined Ltotal and Bmax

Radiation, emittance, energy spread are determined

Transverse non-linearities:

increase with w

Longitudinal non-linearities:

decrease with w

By (s)

By (x)

By/By = 5 10-4 @ 2 cm

SC Wiggler built at BINPBmax = 7 Tfor SIBERIAII

Collaboration with BINP group:

Energy spread – bunch length – rf system

2 22 3

2 42qE

q

CIC

E I I

2c cE EL

s o

c Ec

E heV E

More radiation –larger energy spread – longer bunch

Bunch length can be shortenedby increasing h, V

Natural bunch length and energy spread at low current are definedby the magnetic lattice, the momentum compaction and the rf system

Short bunch length at high current:• Low impedance• High c

• High voltage

1

1,5

2

2,5

3

3,5

4

4,5

50 100 150 200 250 300

FWHM/2.35 (1.5 mA)

FWHM/2.35 (9 mA)

FWHM/2.35 (19 mA)

V [kV]

FWHM/2.3548 [cm]

1

1,5

2

2,5

3

3,5

0 10 20 30 40 50

Measurements 2000Simulation 1998Measurements 2004

I [mA]

FWHM/2.3548 [cm]

2/

2/

c E lth

E e EI

Z n R

Above Ith L increases with the current,

not depending on c

MEASUREMENTS ON DANE

Microwave longitudinal instability

5

10

15

20

25

30

35

0 10 20 30 40 50 60

SigmaZ [mm]

I [mA]

DAFNE e- ring

DAFNE e+ ring

E = 1.2 GeV

E = 0.51 GeV

M.Zobov

Bunch lengthening with current

DANE2:

•ZII/n = 0.6

•Higher c

•Higher p/p (extra wigglers)

•Higher Voltage (V=1.5 MV)

•Ithr = 30 mA @ 0.51 GeV

•Ithr > 50 mA @1.2 GeV

Nominal design current (16 mA)

Present operating currents (12 - 16 mA)

DANE nowZII/n = 1.0 V=0.2 MVZII/n = 0.6 V=0.2 MV

z (m

m)

0,15

0,2

0,25

0,3

0,35

0,4

0 5 10 15 20 25 30

Ib[mA]

y [mm]

Vertical Size Blow Up in DANE now

1,5

2

2,5

3

3,5

4

0 5 10 15 20 25 30

Ib[mA]

FWHM/2.3548 [cm]

- Single bunch (beam) effect

- Correlated with the longitudinal microwave instability:

a) The same threshold

b) The same dependence on Vrf

c) The threshold is higher for higher momentum compaction

d) More pronounced for e- ring

c = 0.02

c = 0.02

c = 0.034

c = 0.034

Bunch length (cm)

y (mm)

Higher Ithr will fight this effect

RF system

A possible candidate cavity

500 MHz SC cavity operating at KEKB

Higher frequencies – lower acceptanceLower frequencies – higher voltage

R&D on SC cavities with SRFF experiment in DAFNE

10

100

1000

0 0.5 1 1.5 2 2.5 3

(min)

V (MV)

E = 1.2 GeV

E = 0.5 GeV

0

5

10

15

20

25

30

0 0.5 1 1.5 2 2.5 3

sigs (mm)@0.51sigs (mm)@1.2

L

(mm)

V (MV)

Touschek beam lifetime and natural bunch lengthas a function of rf voltage (energy acceptance)

E (GeV) 0.51 1.2

E/E (10-4) 6.1 8.4

c 0.08 0.04

High currents

NOW: I- = 1.8 A I+ = 1.3 A routinelyMaximum stored current: I- = 2.4 A I+ = 1.5 A

Experience in Feedbacks - Well in end Going to 2.5 A – no expected difficulties for e-While e-cloud limiting e+ R&D in progress, simulations, possible cures, possibility of Ti coating DANE vacuum chamber

Maximum e- currentStored in any accelerator

NEXT-GENERATION FEEDBACK

AS IT IS(SLAC-LBL-INFN COLLABORATION)

1 - Farm of DSP filters

2 - Down-sampled reconstruction of synchrotron oscillation

3 - Front-end and back-end electronics, together with all the fast digital electronics, i.e.: timing, down-sampler and hold buffer, housed in a VXI system.DSP filters implemented in VME boards. VXI and VME sub-systems linked via high-speed serial links.

Design specifications such to fulfill the ultimate performance specifications of present and new high current multibunch machinesFirst FPGA board prototype tested in DANE

FUTURE(MoU KEK-SLAC signed)

1 - FPGA logic

2 - All samples -> uniform approach for longitudinal and transverse

3 - "ALL-IN-ONE", possibly

August 05

Injection system

•Linac + Accumulatore OK •Doubling transfer lines for optimizing <L>•New kickers (R&D in progress)•Ramping for high energy option

To be studied the possibility of using on – energy injection for the HE and compatibility with SPARXINO

The High Luminosity option needs

continuous injection

STUDIES FOR NEW DAFNE INJECTION KICKERSSTUDIES FOR NEW DAFNE INJECTION KICKERS

present pulse length ~150nst t

VT VT

Schematic of the present injection kicker system and kicker structure

2 kickers for each ring ~ 10mradBeam pipe radius = 44 mmKicker length = 1m

aimed FWHM pulse length ~5.4 ns

E=510 Mev# of bunches=120(max)Stored current=1.5-2.0A

K

K

K

K

Injected bunch: 92

Longitudinal rms motion bunch by bunch at injectione+ ring (July 2005)

Kicker length

Lf - 2L=LB=4z inj140mm

Lr+Lf=2DB 1.6m

Let’s assume: Lr/c=300ps

L 680mmLf/c = 5ns

GENERATOR REQUIREMENTS ((ΘΘnormnorm=0.69mrad.MeV/cm/kV)=0.69mrad.MeV/cm/kV)

t

VIN

Lf /c

Lr /c

Generator pulse shape

Lr /c

Beam energy 510 MeV

Angle of deflection 6 mrad

Stripline length 68 cm

Stripline radius (optimized covarage angle) 30 mm

Required voltage from pulse generator ~65 kV

Average power (max rep. rate 50Hz) 24.5 W

Pulser output current 1400A

t(2L+Lr)/c

(Lf-2L)/c=LB/c

Deflect

ing

volt

ag

e V

T

(2L+Lr)/c

2DB

EVALUATION OF THE KICKER LENGTH (L) EVALUATION OF THE KICKER LENGTH (L) AND THE PULSE SHAPE (Lf , Lr)AND THE PULSE SHAPE (Lf , Lr)

Lf - 2L=LB=0L 750mmLf/c = 5ns

Stripline length 75 cm

Required voltage from pulse generator

~45 kV

Neglecting the bunch length...Neglecting the bunch length...

Optical functions at - energy

IP

DampingWigglers

injection

tuning

RF

Backgroundminimization

IR + section for background minimization

DIPOLE 180° Phase advance between last dipole and QF in IR .

Particles produced inthe dipole will pass near the axis in the quadrupole, and wontbe lost

Scrapers along the ring to stop particles produced elsewhere

Beam direction

Optical functions at 1.2 GeV

injection

RF

DampingWigglers

N-NEnergy per beam E GeV 0.51 1.2

Circumference C m 100 100

Luminosity L cm-2 sec-1 8 1032 1032

Current per beam I A 2.5 0.5

N of bunches Nb 150 30

Particles per bunch N 1010 3.1 3.4

Emittance mm mrad 0.3 0.6

Horizontal beta* x m 1 1

Vertical beta* y cm 1 1.5

Bunch length L cm 1 1.5

Coupling % 1 1

Energy lost per turn Uo (keV) 25 189

H damping time x (msec) 13 5

Beam Power Pw (kW) 62 (55w + 7d) 94.6 (42w + 53d)

Power per meter Pw/m (kW/m) 8.6w + 0.5d 8.4w + 3.8d

F. Sgamma

Tentative schedule

• To -> TDR and Project approval (2006)• To + 1 year -> call for tender• To + 2 years -> construction and delivery• To + 3 years -> DANE decommissioning and

DANE2 installation • To + 4 years -> 1st beam for commissioning and for 1st experiment (2010)

Different experiments must be planned in temporal sequencesince they use the same IR

DAFNE - KLOE KEKB - BELLE

2010 2012 2014 2016 2018 2020

Integrated luminosity typical behavior

0

10

20

30

40

year