1. SLS-2/Cosami meeting Mar. 16, 2016
Andreas Streun Report from 5th DLSR workshop, Mar. 9-11, DESY
Haisheng Xu Report from 2nd TWIICE workshop, Feb. 8-10, Oxford, and latest results on impedances and instabilities
Ciro Calzolaio News from longitudinal gradient superbend design

2. Report from 5th workshop on diffraction limited storage rings DESY, March 9-11, 2016
2 ½ days mixed science & accelerator workshop
New science possibilities (H. Reichert, P. Wilmott)
small emittance  clean undulator spectrum  operation without monochromators
bandwidth  1/(periods  harmonic)  %
imaging & diffraction experiments profit most from lower emittance, spectroscopy less
coherent imaging: sample < probe
low emittance  long working distances  bulky beam line components possible (fabrication)

3. Max IV (M. Eriksson, P. Tavares) Latest commissioning results
74% injection efficiency
stable >120 mA w/o FB & HC  prediction: 40 mA unstable
10 hr lifetime with 80 mA after 20 Ah beam dose
shunts available for gradient correction, not yet used
Misalignments: 25 mm/0.2 mrad element to girder, mm/0.2 mrad girders
100 MHz RF = FM radio, just buy: 5 €/Watt
“flexibility vs. vagueness”: simplify design
“storage rings are consumables”
cost 3 GeV ring = 7% of project
cost 1.5 GeV ring  1 beam line
split functions to different rings, build 1 ring/decade...
plans for MAX IV upgrade or new ring....

4. Project status
SIRIUS (Lin Liu) under construction, start operation 2017
ESRF-EBS (P. Raimondi) procurement in progress
APS-U (G. Decker, V. Sajaev) CDR available, funded (?)
lattice very similar to ESRF; anti-bends under consideration  40 pm
bunch replacement: strong injector / beam dump
Spring8-2 (T. Ishikawa) include ring-XFEL, plans until 2040
PETRA-4 (C. Schroer) 20 pm round, ESRF lattice, CDR 4/2018
Diamond-2 (R. Bartolini) double TBA = ESRF cell w/o center bend
replace user bends by undulators/wigglers
Elettra-2 (E. Karantzoulis) 6BA lattice, CDR in preparation
ALS-U (R. Falcone) coherent soft X-rays, 50 pm round beam
swap out injection using 3rd ring for accumulation
6 mm width NEG coated chambers
Soleil (A. Nadji) first considerations

5. MOGA Kicker magnets Magnet design
ESRF-EBS 3 sextupole + 1 octupole family, 10 seeds DA
SIRIUS 9 quadrupole + 14 sextupole families, DA + Touschek
incl. 2 random misalignments and OCO
constraints on tune, chroma, straight dispersion, lattice symmetry
Diamond-2 + APS-U linear and nonlinear optimization
Kicker magnets
ALS-U swap out: 5.4 ns rise/fall
APS-U swap out: 11.4 ns (15 kV), 5 ns possible
SIRIUS non-linear kicker: 70 mT at 8 mm, 3.2 ms half sine
1.6 kA, 7.6 kV
Magnet design
SIRIUS 3.2 T (!) permanent magnet NdFeB superbend
Elettra-2 3D-girder with lower and upper magnet support for “thin” magnets (i.e. length < radial size)

6. The “large booster club”: SLS, ALBA, SIRIUS, [CANDLE]
Round beams
PETRA-4 Moebius ring with 2 roations per turn
same cell corrects vertical and horizontal chromaticity
build clean –I transformer, non-interleaved SF and SD
problem: DA for using existing injector
Soleil Local round beam insertion under construction [?]
2 x 3 skew quads + s.c. solenoid
apparent emittance hor. and vert. = sqrt(ex ey)
APS-U full coupling ?
The “large booster club”: SLS, ALBA, SIRIUS, [CANDLE]
SIRIUS 50 bends, no straights, 3 pm emittance
Comments on SLS-2
throw away girders, use concrete pedestals (M. Eriksson)
head tail instability dipole mode (m=0) if both momentum compaction and chromaticity are negative (E. Karantzoulis)
feedback can control that (R. Bartolini)