DANE Status Report

C. Milardi, D. Alesini, M.E. Biagini, C. Biscari, R. Boni, M. Boscolo, B. Buonomo, A. Clozza, G. Delle Monache, E. Di Pasquale, G. Di Pirro, A. Drago, L. Falbo, A. Gallo, A. Ghigo, S. Guiducci, M. Incurvati, P. Iorio, C. Ligi, F. Marcellini, C. Marchetti, G. Mazzitelli, L. Pellegrino, M. Preger, L. Quintieri, P. Raimondi, R. Ricci, U. Rotundo, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, S. Tommasini, C. Vaccarezza, M. Vescovi, M. Zobov

Scientific Committee 31 May - 1 Jun 2006

• KLOE run

• Machine studies

• DAFNE shutdown for FINUDA installation

Topics

KLOE off-energy run

Scan of the resonance:Ecm = 1023 MeVEcm = 1030 MeV > 10 pb-1 logged at each pointEcm = 1018 MeV (Nov 2005 ÷ Dec 2005) Ecm = 1010 MeV

Off-energy:Ecm = 1000 MeV 250 pb-1 logged (Jan 2006 ÷ Feb 2006)

Injection systemMagnetic elements scaled according to calibrations

Main Rings• Dipole and quadrupoles scaled according to calibrations• Wigglers constant since they work at maximum power supply current• Optics tuning to preserve the Twiss function @ IP, since the IR is based

on permanent magnet quadrupoles.

DANE off-energy configuration

Peak and daily integrated luminosity during the KLOE runs.

The maximum value of L∫day ~ 10 pb-1 has been obtained in Nov 2005.

The lower values during the 2006 runs correspond to off energy operation.

L∫day

DANE performance for KLOE :nbunches = 105 + 105 up to 111 + 111

I-total = 1.8 A

I+total = 1.3 ALpeak ~ 1.5x1032 cm-2 s-1 L∫day ~ 10 pb-1 (maximum value)L∫KLOE run = 2 fb-1 (May 2004 ÷ Nov 2005)

Lpeak

•LINAC faults (discharges in the klystron modulators, faults in the Uniform Field Solenoid PS)

•Water leakages in several elements (QUADs, RF, WGLs, SPLs)•Vacuum leakages in the e+ ring long sections•Faulty behaviour of the vacuum interlock in the e- RF cavity•Faults in the network connecting the front end processors of the Control System

•Sharing time with other activities (BTF and Synchrotron Radiation)

In the last three months DANE performance off-energy in terms of L∫ has been affected by :

DANE luminosity summary since 2001

The last points with lower L refer to the KLOE off-energy operation.

The Synchrotron Radiation laboratory and the Beam Test Facility (BTF) have been also operated in parasitic mode.

Few dedicated runs have been also delivered to the SR lab for special measurements and to the BTF.

Other activities

BTF experiment 2004/2005: AIRFLY, LCCal, AGILE-TRAKER, LNF-LHCb, CaPiRe, RAP, SIDDHARTA, FLAG, CRYSTAL, MEG, NANO, APACHE-LHCb, MCAL, LAZIO, BTeV, BTFLAB, BENCE, PASSRA, FISA, AIACE, ARGO, P326, GRALL, AGILE satellite, …

The AGILE Gamma Ray Imaging Detector calibration at BTF aimed at obtaining detailed data on all possible geometries and conditions. BTF provided data in the most significant energy region (20-700 MeV)

AGILE satellite in the BTF experimental hall

dedicated run 2 ÷ 20 Nov 2005≈30 % reduction in KLOE L∫

Machine studies (@ nominal E)(last two weeks in March)

•Study of background to KLOE during injection

•Test on the wires for Beam Beam Long Range interaction (BBLR) compensation

•Analysis of the KLOE background as a function of the scrapers position

•Test of the new transverse feedback in the e+ vertical plane

•Injection from the Linac switching off the chicane downstream the e+ converter

•Test on the new acquisition system for the single turn orbit measurements

•Test on the timing system to control the new power supply of the BTF pulsed magnet

•Bunch length measurements with an optics with a large negative c (~ -0.036)

•Optics measurements on the Transfer Lines

All machine studies were aimed at improving DANE performance for the next FINUDA run and at defining design criteria for an upgraded machine.

Optics application & tuningRF phase tuningCentral frequency 368.232 MHzResponse matrix acquisition & orbit correction

Bunch lenght measurement vs. I- at several values of VRF

fs = 38.3 KHz, VRF = 119 KV -> ac ~ - 0.036

e- ring optics c= -.036 (one day of machine study)

x model (line)

measured (points)

0

0,5

1

1,5

2

2,5

3

3,5

0 5 10 15 20 25

I [mA]

FWHM/2.35 [cm]

e-: 97 kV, -0.037

e- : 130 kV, +0.021

0

0,5

1

1,5

2

2,5

0 5 10 15 20 25

I [mA]

FWHM/2.35 [cm]

e+

e-

e- Lb versus stored current for:c = 0.02 red squaresc = - 0.036 blue dots

Lb versus stored current for:e+ c = 0.02 red squarese- c = - 0.036 blue dots

KLOE nominal optics c ~ 0.02

0,8

1

1,2

1,4

1,6

1,8

2

2,2

0 5 10 15 20

I [mA]

FWHM/2.35 [cm]

2 mA 7 mA

c = - 0.036VRF = 97 KV

c = - 0.021

VRF= 165 KV

Ith c3 / 2VRF

1/ 2

Microwave instability threshold Ith in the e- ring

Ith scales with c as expected

• Microwave instability threshold is reduced by a factor 3:

2 mA @ c = - 0.021

7 mA @ c = - 0.036

• With the same instability threshold the electron bunch length in the lattice with c = - 0.036 is ≈ 50% shorter than in the nominal conditions (c = + 0.02)

• The electron bunch is shorter than the positron one with nominal c

What have we learned from the shifts with c ~ -0.036 ?

In the DANE IRs the beams experience 24 Beam Beam Long Range interactions (parasitic crossing) limiting the maximum storable current.

Numerical simulations show that BBLR interaction can be compensated by current-carrying windings.

Wires for BBLR compensation

compensation wiresncoils = 20y

I

I

L = .215 m

z

L = .18 m

Wires installed in the KLOE Interaction Region (Nov 2005)

(G. Sensolini, R. Zarlenga)

Z = 4.887 m

IP1compensation winding

KLOE half IR simplified top view

Splitter

x

0

2000

4000

6000

8000

1 104

1.2 104

2.5 104 2.6 104 2.7 104 2.8 104 2.9 104 3 104

KLOE_20060322_fast

L [1

02

8 c

m-2

s-1]

Time [s]

0

200

400

600

800

1000

1200

1400

1600

2.5 104 2.6 104 2.7 104 2.8 104 2.9 104 3 104

KLOE_20060322_fast

I- [mA]

I+ [mA]

I- [mA

]

Time [s]

0

1000

2000

3000

4000

5000

6000

2.5 104 2.6 104 2.7 104 2.8 104 2.9 104 3 104

KLOE_20060322_fast

- [s]

+ [s]

- [s]

Time [s]

0

1000

2000

3000

4000

5000

6000

3000 4000 5000 6000 7000 8000

KLOE_20060322_fast

- [s]

+ [s]

- [s]

A

0

200

400

600

800

1000

1200

1400

1600

3000 4000 5000 6000 7000 8000

KLOE_20060322_fast

I- [mA]I+ [mA]

I [m

A]

Time [s]

0

2000

4000

6000

8000

1 104

1.2 104

3000 4000 5000 6000 7000 8000

KLOE_20060322_fast

L [

102

8 c

m-2

s-1]

Time [s]

WIRES

ON

WIRES

OFF

L I

400

500

600

700

800

900

1000

1100

0

2000

4000

6000

8000

1 104

-500 0 500 1000 1500 2000 2500 3000 3500

KLOE_21_22Mar06_merge 3:14:09 PM 24/5/06

I+ wires On

I+ [mA] wires OFF

+ wires ON

- wires OFF

I+ [

mA

] +

t [s]

higher lifetime +

beam lifetime independent from the other beam currentless beam-beam blow upDue to the higher + is possible to have the same L with less injections

What have we learned from the shifts with WIRES ?

DAFNE shutdown on March 31st

• Maintenance

• KLOE roll-out

• Upgrades

• FINUDA roll-in

Maintenance

• Plants:ElectricCoolingCryogenic

• Linac• Fuid system• Control System• Magnet power supplies• RF system• Vacuum system• Wigglers

Upgrades

Wiggler cooling system upgrade 8 Wigglers~ 150 spigots each wiggler

Simplified IR1 for FINUDA run

•IP1 • KLOE detector removed

• 4 electromagnetic QUADs • Compensator solenoids off

in order to have:• a flexible lattice• release the low beta configuration @ IP1• have a more efficient beam separation in IR1• have the same * @ IP2 as for KLOE

y = 0.018 m

x = 1.6 m

IR1 for FINUDA run

KLOE roll-out

removed

disconnected

moving

Ion-Clearing-Electrodes

Remove broken Ion-Clearing-Electrodes in the e- ring

Remove ICEs in the e- ring wigglers to reduce ring coupling impedance

In order to:

•Increase - geometric Luminosity - dynamics Luminosity

•Reduce - beam blow up above the microwave instability threshold - impact of quadrupole instability in the e- ring

MOTIVATION:

• Impedance of the DAFNE Main Rings:

• Impedance affects bunch length:

z- ≈ 2.7cm

z+ ≈ 2 cm measured @ Ib ~ 15 mA

e+

e-

mainly due to ICE in WGLs

Remove Ion Clearing Electrodes in e- Wigglers

3/13/1

6/12

o

z

n

Z

R

cRFs

c

hV

I

eE

I

cos

2

/2

Z

n

0

0.54

Z

n

0

1

e- Vertical Size Blow f(VRF, Ib)

10

15

20

25

30

35

0 10 20 30 40

I [mA]

e+ ring

e- ring

Bunch Length [mm]

~ 30%

0,15

0,2

0,25

0,3

0,35

0,4

50 100 150 200 250 300

1.5 mA9 mA19 mA

V [kV]

y [mm]

~ 66%

• Impedance affects vertical beam size as well

0,15

0,2

0,25

0,3

0,35

0,4

0 5 10 15 20 25 30

Ib[mA]

y [mm]

e- Vertical Size Blow Up

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

- It is correlated with the longitudinal microwave instability:

a) The same threshold

b) The same dependence on RF voltage

c) The threshold is higher for higher momentum compaction

d) More relevant for e- ring having higher coupling impedance

c = 0.02

c = 0.02

c = 0.034

c = 0.034

Vertical size

Bunch length

Conditions z (e-), cm z (e+), cm Gain, %

Normal operation

3.0 (meas.) 2.1 (meas.)

Low Impedance 2.3 2.1 18

A factor 2 reduction in e- ring impedence gives a GEOMETRIC LUMINOSITY GAIN

z 2

z 2

If x,y scale as

DAFNE Arc Chamber – Remote Tooling

Multipurpose remotized positioning system

y

x

About ICE removal

DAFNE Arc Chamber – Remote Tooling

Milling machine to cut ICE fingers

to extract them as a whole

finger

20 mm120 mm

Pneumatic piston Suction cupICE

Extractor fan

ICE break and removal ( backup solution)

Vacuum chamber cleaning

Wires for BBLR compensation in the IR2

Windings OFF Windings ON Windings ON(wrong polarity)

Particle equilibrium density in the transverse space of normalized betatron amplitude

Numerical simulations show that BBLR interactions can be compensated by current-carrying windings

Ay/ y

Ax/x

Ay/ y

Ay/ y

Ax/x Ax/x

New feedback board

Under test at SLAC,

KEK and LNF

Feedback upgrade III generation digital bunch-by-bunch feedback designed for

SuperB factory (collaboration SLAC-KEK-LNF)

- Features:- extremely compact- gain & phase digital and remote control- possibility to manage any betatron or synchrotron tunes - less sensitive to large oscillations at injection- real time parameter monitoring- powerful beam diagnostics- main DSP loop based on FPGA (Field Programmable Gate Array)

Power supplyHard disk unit PersonalComputer

Fan

Feedback test board

30cm

New Beam Position Monitors

5 complete stations will be installed on each ring for:

• single turn position measurements

• linear and nonlinear optics measurements( x,y x,y c11)

TiN coating

First test on a short straight section of the e+ ring in order to measure the e-cloud by using an e-cloud detector keeping as a reference the data coming from a symmetric section without coating.

2 e-cloud detectors will be installed in the e- ring

Control System

• Upgrade of the CS servers

• Gradual implementation of new front-end processors (Pentium/Linux)

• Extension of the CS Ethernet network in the LINAC area, BTF experimental hall, Damping Ring area, DAFNE hall

• Control software implementation for the new elements

New Injection Kickers

Expected benefits:•higher maximum stored currents•Improved stability of colliding beams during injection• less background allowing acquisition on during injection ? (it was off during FINUDA last run)

(D. Alesini and F. Marcellini)

New injection kickers with 5.4 ns pulse length have been designed to reduce the perturbation on the stored beam during injection

present pulse length ~150ns(old kickers)

t t

VT VT

FWHM pulse length ~5.4 ns

50 bunches 3 bunches

spectrometer

silicon tagging target

silicon detector

•high intensity beam (103-1010 particles)•Installation of a pulsed power supply to improve the duty cycle from 40% to 80% (June 2006)

•Installation of the Photon Tagged Source

BTF upgrades

BTF photon tagged source

experimental hall

Maintenance activities on schedule

KLOE roll-out completed

Finuda straight section removed, IR2 ready for FINUDA roll-in

All wigglers removed, hydraulic and electric maintenance almost completed, 2 magnets re-installed and aligned

Tests for ICE removal completed and removal scheduled for next week

Present status

Aug 7th ÷ Aug 28th summer shutdown

DANE startup ts depends on the FINUDA roll-in tr

ts = tr + (~13 days)

Thanks to the DANE Technical Staff !!

G. Baldini, P. Baldini, A. Battisti, A. Beatrici, M. Belli, B. Bolli, A. Camiletti, G. Ceccarelli, R. Ceccarelli, A. Cecchinelli, S. Ceravolo, R. Clementi, O. Coiro, S. De Biase, M. De Giorgi, N. De Sanctis, R. Di Raddo, M. Di Virgilio, G. Ermini, G. Fontana, U. Frasacco, C. Fusco, F. Galletti, M. Giabbai, O. Giacinti, E. Grossi, F. Iungo, R. Lanzi, V. Lollo, V. Luppino, M. Marchetti, C. Marini, M. Martinelli, A. Mazzenga, C. Mencarelli, M. Monteduro, A. Palleschi, M. Paris, E. Passarelli, V. Pavan, S. Pella, D. Pellegrini, R. Pieri, G. Piermarini, G. Possanza, S. Quaglia, F. Ronci, M. Rondinelli, F. Rubeo, M. Sardone, M. Scampati, G. Sensolini, R. Sorchetti, A. Sorgi, M. Sperati, A. Sprecacenere, P. Tiseo, R. Tonus, T. Tranquilli, M. Troiani, V. Valtriani, R. Zarlenga, A. Zolla.

…. for their commitment during DANE operation and shutdown