DAFNE Status Report

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DAFNE 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
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Topics

• KLOE run
• Machine studies
• DAFNE shutdown for FINUDA installation

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KLOE off-energy run
Scan of the F resonance Ecm 1023 MeV Ecm
1030 MeV gt 10 pb-1 logged at each
point Ecm 1018 MeV (Nov 2005
Dec 2005) Ecm 1010 MeV Off-energy Ecm
1000 MeV 250 pb-1 logged (Jan 2006
Feb 2006)
DAFNE off-energy configuration

• Injection system
• Magnetic 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 _at_
  IP, since the IR is based on permanent magnet
  quadrupoles.

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DAFNE performance for KLOE nbunches 105
105 up to 111 111 I-total 1.8
A Itotal 1.3 A Lpeak 1.5x1032
cm-2 s-1 L?day 10 pb-1 (maximum
value) L?KLOE run 2 fb-1 (May 2004 Nov 2005)
Lpeak
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
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In the last three months DAFNE performance
off-energy in terms of L? has been affected by

• 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)

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DAFNE luminosity summary since 2001
The last points with lower L refer to the KLOE
off-energy operation.
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Other activities
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.
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,
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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?
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Machine studies (_at_ 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 ac ( -0.036)
• Optics measurements on the Transfer Lines

All machine studies were aimed at improving DAFNE
performance for the next FINUDA run and at
defining design criteria for an upgraded machine.
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e- ring optics ac -.036 (one day of machine
study)
Optics application tuning RF phase
tuning Central frequency 368.232 MHz Response
matrix acquisition orbit correction Bunch
lenght measurement vs. I- at several values of
VRF fs 38.3 KHz, VRF 119 KV -gt ac - 0.036
h-x model (line) measured (points)
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KLOE nominal optics ac 0.02
Lb versus stored current for e ac 0.02
red squares e- ac - 0.036 blue dots
e- Lb versus stored current for ac 0.02
red squares ac - 0.036 blue dots
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Microwave instability threshold Ith in the e- ring
ac - 0.036 VRF 97 KV
ac - 0.021 VRF 165 KV
2 mA
7 mA
Ith scales with ac as expected
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What have we learned from the shifts with ac
-0.036 ?

• Microwave instability threshold is reduced by a
  factor 3
• 2 mA _at_ ac - 0.021
• 7 mA _at_ ac - 0.036
• With the same instability threshold the electron
  bunch length in the lattice with ac - 0.036 is
  50 shorter than in the nominal conditions (ac
  0.02)
• The electron bunch is shorter than the positron
  one with nominal ac

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Wires for BBLR compensation
In the DA?NE 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.
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Wires installed in the KLOE Interaction Region
(Nov 2005)
(G. Sensolini, R. Zarlenga)
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W I R E S O N
L
I
t
W I R E S O F F
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What have we learned from the shifts with WIRES ?
higher lifetime t beam lifetime independent from
the other beam current less beam-beam blow up Due
to the higher t is possible to have the same L
with less injections
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DAFNE shutdown on March 31st

• Maintenance
• KLOE roll-out
• Upgrades
• FINUDA roll-in

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• Maintenance
• Plants
• Electric
• Cooling
• Cryogenic
• Linac
• Fuid system
• Control System
• Magnet power supplies
• RF system
• Vacuum system
• Wigglers

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Upgrades
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Wiggler cooling system upgrade
8 Wigglers 150 spigots each wiggler
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Simplified IR1 for FINUDA run

• KLOE detector removed
• 4 electromagnetic QUADs
• Compensator solenoids off

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

by 0.018 m bx 1.6 m
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IR1 for FINUDA run
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KLOE roll-out
disconnected
moving
removed
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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

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Remove Ion Clearing Electrodes in e- Wigglers

• MOTIVATION
• Impedance of the DAFNE Main Rings
• Impedance affects bunch length
• sz- 2.7cm
• sz 2 cm measured _at_ Ib 15 mA

e-
mainly due to ICE in WGLs
e
e- Vertical Size Blow f(VRF, Ib)
Impedance affects vertical beam size as well
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e- Vertical Size Blow Up
Vertical size
ac 0.02

• - Single bunch (beam) effect
• - It is correlated with the
• longitudinal microwave
• instability
• The same threshold
• The same dependence on RF voltage
• The threshold is higher for higher momentum
  compaction
• More relevant for e- ring having higher coupling
  impedance

ac 0.034
Bunch length
ac 0.02
ac 0.034
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A factor 2 reduction in e- ring impedence gives a
GEOMETRIC LUMINOSITY GAIN
If bx,y scale as
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About ICE removal
Multipurpose remotized positioning system
y
x
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Milling machine to cut ICE fingers
120 mm
20 mm
finger
to extract them as a whole
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ICE break and removal ( backup solution)
Pneumatic piston
Suction cup
ICE
Vacuum chamber cleaning
Extractor fan
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Wires for BBLR compensation in the IR2
Numerical simulations show that BBLR interactions
can be compensated by current-carrying windings
Particle equilibrium density in the transverse
space of normalized betatron amplitude
Ay/sy
Ay/sy
Ay/sy
Ax/sx
Ax/sx
Ax/sx
Windings OFF
Windings ON
Windings ON (wrong polarity)
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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)
New feedback board Under test at SLAC, KEK and LNF
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Power supply
Personal Computer
Hard disk unit
30cm
Fan
Feedback test board
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• New Beam Position Monitors
• 5 complete stations will be installed on each
  ring for
• single turn position measurements
• linear and nonlinear optics measurements( n x,y
  b x,y k c11)

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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
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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

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(D. Alesini and F. Marcellini)
New Injection Kickers
New injection kickers with 5.4 ns pulse length
have been designed to reduce the perturbation on
the stored beam during injection
VT
VT
3 bunches
50 bunches
t
t
present pulse length 150ns (old kickers)
FWHM pulse length 5.4 ns

• 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)

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BTF upgrades
experimental hall

• 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 photon tagged source
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Present status
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
DAFNE startup ts depends on the FINUDA roll-in
tr ts tr (13
days)
Aug 7th Aug 28th summer shutdown
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Thanks to the DAFNE 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 DAFNE operation
and shutdown