DAFNE UPGRADE

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DAFNE UPGRADE

• DAFNE Upgrade Team

Scientific Committee-May 14-15, 2007 LNF - Italy
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Crabbed Waist in 3 Steps

1. Large Piwinskis angle F tg(q)sz/sx
2. Vertical beta comparable with overlap area by
   sx/q
3. Crabbed waist transformation y xy/(2q)

P. Raimondi, November 2005
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Crabbed Waist Advantages

1. Geometric luminosity gain
2. Very low horizontal tune shift

• Large Piwinskis angle
• F tg(q)sz/sx
• 2. Vertical beta comparable
• with overlap area
• by sx/q
• 3. Crabbed waist transformation
• y xy/(2q)

1. Geometric luminosity gain
2. Lower vertical tune shift
3. Vertical tune shift decreases with oscillation
   amplitude
4. Suppression of vertical synchro-betatron
   resonances

1. Geometric luminosity gain
2. Suppression of X-Y betatron and synchro-betatron
   resonances

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Parameters used in simulations
Horizontal beta _at_ IP 0.2 m (1.7 m)
Vertical beta _at_ IP 0.65 cm (1.7 cm)
Horizontal tune 5.057
Vertical tune 5.097
Horizontal emittance 0.2 mm.mrad (0.3)
Coupling 0.5
Bunch length 20 mm
Total beam current 2 A
Number of bunches 110
Total crossing angle 50 mrad (25 mrad)
Horizontal beam-beam tune shift 0.011
Vertical beam-beam tune shift 0.080
L gt 2.2 x 1033 cm-2 s-1
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SIDDHARTA IR Luminosity Scan
Crab On --gt 0.6/q
Crab Off
Lmax 2.97x1033 cm-2s-1 Lmin 2.52x1032 cm-2s-1
Lmax 1.74x1033 cm-2s-1 Lmin 2.78x1031 cm-2s-1
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Dynamic Aperture
Dynamic Aperture tune scan
Luminosity tune scan

• D.Shatilov, M.Zobov

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Off Energy Dynamic Aperture

• D.Shatilov, M.Zobov

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Beam Lifetime
Comparison between Siddharta and FINUDA lattices
for the same beam parameters
?RF 1 No scrapers
Touschek lifetime is evaluated taking into
account vacuum chamber aperture but no dynamic
aperture
S. Guiducci
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Trajectories of Touschek particles generated all
along the ring that get lost at the IR
Simulation shows how collimators strongly reduce
background at the IR
SCHPL110
SCHPS101
SCHPL201
IP
SCHPL101
SCHPS201
Set of scrapers minimizing IR background
SCHPL101 8.5sx 11 mm (moved at s -8.2 m
from IP) SCHPL110 18sx 18 mm SCHPS201 21
sx 21 mm (moved at s -44 m from IP)
M. Boscolo
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Beam lifetime as a function of the scrapers
aperture
S. Guiducci
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New Crossing Regions Layout

• remove splitters (on both interaction regions)
• new vacuum chambers for IP regions
• adjust dipole fields and position (Blong lower,
  Bshort higher - splitters power supplies)
• new permanent magnets in the IP1 region
• readjust all the other elements (quads, sexts
  etc)
• new components construction (kickers, bellows,
  diagnostics, etc)
• new vacuum system for IP regions

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Crossing Region layout cont.
IP
QD0s
QF1s
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Large Crossing Angle and Crabbed Waist Scheme
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Large Crossing Angle and Crabbed Waist Scheme
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S. Tomassini et all.
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• Aluminum made (very cheap)
• Thin window thickness 0.3 mm
• Mechanical and Vacuum test done
• Construction in progress

permanent SmCo quads
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New Shielded bellows
Axial working stroke 5 mm Radial offset 3 mm

• HFSS simulation
• Beam excited fields in the bellows structure
• No significant fields in the volume beyond the
  shield

F.Marcellini, G. Sensolini
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compensator
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half moon chamber complete beam
separation shape to fit inside existing quads
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IP2 Y is completely symmetric to IP1 except
forcrab waist sextupoles and compensator
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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

F. Marcellini, D. Alesini, G. Sensolini , S. Pella
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Fast Kickers

• Kicker prototype preliminary test performed
• Kicker final design completed
• Pulse generator prototype under test (80 hours
  tested _at_3Hz done)
• 50 KV final feedthrough will be tested next week
• Delivery of the first Kicker by the end of May
• Engineering of pulse system supply and controls
  implementation already order to the manufacture
• Improved pulser version by the end of May
• Remote controls implementation for August

F. Marcellini, D. Alesini, G. Sensolini, S. Pella
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VACUUM CHAMBER modifications

• 80 m long of storage ring reshaped (40 of DAFNE
  storage ring)
• 70 m long of new vacuum chambers designed and
  under manufacturing
• Designed new shielded bellows
• Vacuum plant upgraded quotation for new pumping
  units in progress
• New fast kickers manufacturing in progress

QTÀ Esistenti DA COSTRUIRE NUMERO PARTE DESCRIZIONE NOTE
6 4 2 SR02-100   Disegni OK / Richieste offerte
8 1 7 SR02-092   Disegni OK / Richieste offerte
2 2 0 SR02-093   Riusata
4 4 0 SR02-123   Riusata
8 8 0 RF-All-Metal Gate Valve RF-All-Metal Gate Valve Riusate
4 0 4 SR02-009-000    
4 2 2 sr02-133   Disegni OK / Richieste offerte
2 2 0 SR02-131   Riusata
4 0 4 SR02-013-000    
4 0 4 SR02-006-000    
2 0 2 SR02-002-000  
16 0 16 CV-soffietto   KEK Like or FRASCATI Like?
1 0 1 Camera x_C   Disegni 90 / richieste offerte
4 0 4 Camera x_C_taper   Disegni 90 / richieste offerte
4 0 4 tronchetto1    
2 0 2 tronchetto3    
2 0 2 tronchetto4    
4 2 2 DAFNE-005-070   Disegni OK / Richieste offerte
12 1 11 DAFNE-005-030   Disegni OK / Richieste offerte
12 8 4 Pompa Ionica 120LS   Richieste offerte (Clozza)
30 11 19 Pompa Ionica 240LS-A   Richieste offerte (Clozza)
4 0 4 gomito90   Disegni OK / Richieste offerte
1 0 1 camera sottile 55   Disegni OK / Richieste offerte
2 0 2 DAFNEUP-001-000 IP1-VACUUM Y CHAMBER Disegni OK / Richieste offerte
4 0 4 SR02-008-000    
2 0 2 SR02-012-000    
4 0 4 SR02-011-000    
2 0 2 SR02-017-000    
2 0 2 sr02-018-000    
2 0 2 SR02-014-000    
2 2 0 SR02-081   Riusata
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SIDDHARTA Setup
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Machine luminosity monitors and IP diagnostics
tool

• e e- ? e e- g (8.5e-26 cm-2s-1_at_Egt100MeV, 95
  1.7mrad)e e- ? e e- Z g (lt10 background)
• e e- ? e e- g g (6.6e-29 cm-2s-1_at_Egt100MeV, 15
  1.7mrad)now limited by accidentals (_at_1032 and
  chamber vertical acceptance)
• e e- ? e e- Bhabha scattering - more clean
  process312.5 Hz _at_ 18oltqlt27o _at_ 1033cm-2 s-1

F. Bossi, P. Branchini, B. Buonumo, G.
Mazzitelli, F.Murtas, P.Valente DAFNE-KLOE
collaboration with the support of SSCR
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Luminosity monitor for SIDDAHRTA run
TILE CALORIMETER
g MONITOR PbWO4 crystal
GEM RING
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Tile Bhabha calorimeter (lumi)

• 4 calorimeter composed by 5 30o sectors
• 7 lead sheet 5mm - 3 final lead sheet 10mm
• 12 30o scintillating tile for sector
• 3 WLS each tile
• 1 PM for any sector (20 PM)
• 12.5 X0 15 resolution _at_ 510 MeV

• First tail Russian sample arrived
• WLS installed and light emission tested
• BTF test planed for October
• PM, Electronics and DAQ by KLOE

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A 3GEM Monitor for DAFNE
rectangular GEM prototype under test _at_ DAFNE
10 cm
2.4 cm
Annular gem foil design for bhabha detector_at_
DAFNE
2.4 cm
64 pads
10 cm
The read out has been realized using 8 chip ASDQ
(8 channel each) Test at BTF 99 efficiency for
electron (signal in bhabha measure) 1
efficiency for photons (background in bhabha
measure)
32 32 channels
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3GEM monitor test on DAFNE
On April 2007 the 3gem chamber has been put at
zero degree on DAFNE for photon detection coming
from the FINUDA interaction region
e -
3GEM
e
lead
beamstrahlung g
number of photon vs timeand FINUDA luminosity
photon spot-size
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Order Status Progress
Layout desig. Estimate (Keuro) request order Note
IP QUADS OK 380 OK OK (ASTER)
IP1 chambers OK 47 OK OK Complete of vacuum test (CECOM)
chambers OK 20.8 OK OK Complete of vacuum test (RMP)
chambers OK 30 OK In prog.
IP2 chambers OK 30 In prog.
KCK chamber OK 18 In prog.
Vacuum pumps OK 150 OK In prog. tender
IP1/IP2 bellows OK 70 OK In prog.
Manpower 45 OK OK
IP2 platform OK 10 OK OK
Chamber Supports OK 20 In prog
LUMI (sigle/bhaba/GEM) OK 45 OK In prog. 80 done
Total 865.8
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Time line
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Time line
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LHC Upgrade
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spare
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DAFNE-UP KLOE
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DAFNE-UP FINUDA
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Luminosity and crossing angle

crossing angle q (Piwinski angle F)
high density N low by low sx
luminosity is limited by hourglass and tune-shift
effects
y
y
by
by
z
z
The introduction of a crossing angle do NOT
improve luminosity
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luminosity and tune-shift
bat allows to play with transversal dimension sx
and by optical function, kipping limited the
vertical tune-shift and strongly depressing
horizontal tune-shift

• sz large
• sx small

bat a large Piwinski angle can generate strong
sincro-bethatron oscillation
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Suppression of X-Y Resonances
Horizontal oscillations
sextupole

• Performing horizontal oscillations
• Particles see the same density and the same
  (minimum) vertical beta function
• The vertical phase advance between the sextupole
  and the collision point remains the same (p/2)

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Increase Positron Current

1. New Injection Kickers
2. New Feedback Systems
3. Ti-Coating

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Optical Function
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Wiggler linearization
CURVED POLE
Reduction of the octupole around the beam
trajectory in the region of the poles
Proposed by Pantaleo
MOVING MAGNETIC AXIS
Compensation of the integrated octupole in each
semiperiod
S. Bettoni 28/3
New method
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Shifted Poles Model
For the moment shifted the coils with the poles
S. Bettoni 28/3
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Analysis of the results comparison with the
experimental data
S. Bettoni 28/3