DA  NE 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: E cm = 1023 MeV E cm = 1030 MeV > 10 pb -1 logged at each point E cm = 1018 MeV (Nov 2005 ÷ Dec 2005) E cm = 1010 MeV Off-energy: E cm = 1000 MeV 250 pb -1 logged (Jan 2006 ÷ Feb 2006) 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 IP, since the IR is based on permanent magnet quadrupoles. DA  NE 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 The lower values during the 2006 runs correspond to off energy operation. L ∫day DA  NE performance for KLOE : n bunches = up to I - total = 1.8 A I + total = 1.3 A L peak ~ 1.5x10 32 cm -2 s -1 L ∫day ~ 10 pb -1 (maximum value) L ∫KLOE run = 2 fb -1 (May 2004 ÷ Nov 2005) L peak

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 DA  NE performance off-energy in terms of L ∫ has been affected by :

DA  NE 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 ( 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 (~ ) Optics measurements on the Transfer Lines All machine studies were aimed at improving DA  NE performance for the next FINUDA run and at defining design criteria for an upgraded machine.

Optics application & tuning RF phase tuning Central frequency MHz Response matrix acquisition & orbit correction Bunch lenght measurement vs. I - at several values of V RF f s = 38.3 KHz, V RF = 119 KV -> ac ~ e - ring optics  c = (one day of machine study)   x model (line) measured (points)

e - L b versus stored current for:  c = 0.02 red squares  c = blue dots L b versus stored current for: e +  c = 0.02 red squares e -  c = blue dots KLOE nominal optics  c ~ 0.02

2 mA7 mA  c = V RF = 97 KV  c = V RF = 165 KV Microwave instability threshold I th in the e - ring I th scales with  c as expected

Microwave instability threshold is reduced by a factor 3: 2  c =  c = With the same instability threshold the electron bunch length in the lattice with  c = is ≈ 50% shorter than in the nominal conditions (  c = ) The electron bunch is shorter than the positron one with nominal  c What have we learned from the shifts with  c ~ ?

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. Wires for BBLR compensation

compensation wires n coils = 20 y I I L =.215 m z L =.18 m Wires installed in the KLOE Interaction Region (Nov 2005) (G. Sensolini, R. Zarlenga) Z = m IP1compensation winding KLOE half IR simplified top view Splitter x

WIRES ONWIRES ON WIRES OFFWIRES OFF L I 

higher lifetime  + beam lifetime independent from the other beam current less beam-beam blow up Due 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 31 st Maintenance KLOE roll-out Upgrades FINUDA roll-in

Maintenance Plants: Electric Cooling Cryogenic 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 IP1 have a more efficient beam separation in IR1 have the same  IP2 as for KLOE   y = 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 I b ~ 15 mA e+e+ e-e- mainly due to ICE in WGLs Remove Ion Clearing Electrodes in e - Wigglers e - Vertical Size Blow f(V RF, I b ) ~ 30% ~ 66% Impedance affects vertical beam size as well

e- Vertical Size Blow Up - 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 = Vertical size Bunch length

Conditions  z (e - ), cm  z (e + ), cm Gain, % Normal operation 3.0 (meas.)2.1 (meas.) Low Impedance A factor 2 reduction in e - ring impedence gives a GEOMETRIC LUMINOSITY GAIN 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 mm 120 mm

Pneumatic pistonSuction cupICE Extractor fan ICE break and removal ( backup solution) Vacuum chamber cleaning

Wires for BBLR compensation in the IR2 Windings OFFWindings 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/yAy/y Ax/xAx/x Ay/yAy/y Ay/yAy/y Ax/xAx/x Ax/xAx/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 supply Hard disk unit Personal Computer 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  c 11 )

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 VTVT VTVT FWHM pulse length ~5.4 ns 50 bunches 3 bunches

spectrometer silicon tagging target silicon detector high intensity beam ( 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 7 th ÷ Aug 28 th summer shutdown DA  NE startup t s depends on the FINUDA roll-in t r t s = t r + (~13 days)

Thanks to the DA  NE 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 DA  NE operation and shutdown