Future developments at the ESRF

1
Future developments at the ESRF

• Outline
• Beam current increase
• Small aperture vacuum chambers
• ESRF II

2
Beam current increase (1)
Design current 1992 100 mA
1996 200 mA
2006 300 mA

• Main limitation HOM driven coupled-bunch
  instabilities
• Cured up to 200 mA by a precise control of
  cavity temperature

• Solution for higher current fast multibunch
  longitudinal feedback

3
Beam current increase (2)
Longitudinal feedback based on fast digital
signal processing

• Feasibility study completed
• Detailed design and construction launched
• Longitudinal kicker based on SLS design
• Low level RF front ends under development
• Tenders for FPGA

First tests in November 2005
4
Beam current increase (3)
Possible issues
Heatload on SR vacuum chamber and front-ends OK
Bremsstrahlung in the ID straight section OK
RF system transmitters OK number of
cavities OK power on windows OK
5
Beam current increase (4)

• New vacuum system

• Multibunch feedback possibly sufficient

• HOM damped cavities
• - Superconducting cavities
• (SOLEIL, Cornell type)
• - Room temperature cavity
• (EU project)

6
Small aperture vacuum chambers (1)
R D triggered by ESRF II

• Resistive wall impedance b3
• Replace stainless steel by aluminium (or
  copper)

Issues

• Conductance b3
• Replace localised pumping by NEG coating

7
Small aperture vacuum chambers (2)
Test new Al NEG coated CV3 chambers in the ID6
straight section January 2005 SOLEIL
type May 2005 30 x 20 mm
8
ESRF II
Start a reflection on long-term improvements of
the ESRF storage ring performances with keeping
untouched the existing tunnel and beamlines
9
Lattice studies for ESRF II (1)
TBA optics Ultimate emittance for a 6 GeV, 32
cells lattice 0.66 nm
10
Lattice studies for ESRF II (2)
11
Lattice studies for ESRF II (3)
DBA optics with longitudinally varying dipole
field
Quadrupole matching sections to be optimised