1 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 NSLS-II Mechanical Subsystems Accelerator Systems Advisory Committee Review October 10-11, 2006 Sushil Sharma J. SkaritkaR. Alforque C. StelmachB. Rusthoven W. MengN. Simos V. RavindranathS. Pjerov H. Amick S. Mason G. Mahler

2 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 Outline Booster Magnets – Installation and Alignment Storage Ring (SR) Magnets  SR Magnet- Girder Assemblies  Alignment and Installation Vibration and Thermal Stability Issues SR Absorbers and Scrapers

3 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 Storage Ring Tunnel Booster in SR tunnel SR Beam height: 1.0 m Beamline height: 1.4 m SR tunnel: 3m x 2.75m

4 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/ D Model of the SR Tunnel The booster follows the layout of the storage ring. There are no booster magnets over the SR straight section The tunnel will not be too crowded due to:  Low and narrow profiles of SR girders  Compact designs of the front end components  Small sizes of the booster magnets

5 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 MagnetNumber of magnetsLength, mStrength Dipole60 (1 family) T,  2.1 T/m Quadrupole60 (1 family) 30 (1 family) 6 (1 family) T/m 10 T/m <0.5 T/m Sextupole15 (1 family) T/m 2 Orbit corrector 60 (x and y)0.2<1 mrad Booster Magnets Dipole Quadrupole Sextupole Reference designs will be developed for air- cooled magnets to be hung from the ceiling of the SR tunnel.

6 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 Booster Magnet Field Calculations 2-D field calculations were performed to verify good field regions and to ensure acceptable magnet sizes for the air- cooled magnets MagnetWeight (kg) Dipole580 Quadrupole45 Sextupole(0.4m)55 Sextupole (0.2m)30

7 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 Booster Magnet Installation The booster magnets will be installed before the SR magnets. Commercial Pallet stackers (turning radius ~ 1.5 m) can be used for lifting the magnets to required heights.

8 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 Booster Magnet Alignment Set-Screw Alignment Differential Truss Alignment Different alignment mechanisms are being considered including a removable alignment mechanism consisting of jacks and translation stages.

9 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 Number ofMagnet TypeLengthB,B',B"Gap, Dia. Field Alignment Magnets (m)T,T/m,T/m^2mmTolerance 60Dipole , 0, %0.1mm, 0.5mrad 330Quadrupole(S)0.30, 21, %0.03 mm, 0.2mrad 30Quadrupole(L)0.40, 21, %0.03mm, 0.2mrad 30Sextupole(L)0.30, 0, %0.03 mm, 0.2mrad 120Sextupole(M)0.250, 0, %0.03mm, 0.2mrad 240Sextupole(S)0.20, 0, %0.03mm, 0.2mrad 180H&V&SQ Corrector ,36,0 0.1mm, 0.2mrad 30H Correctors , 0, 0 < 104Fast H&V Corrector , Magnet Girders 0.1 mm, 0.5mrad Storage Ring Magnets The dipole gap was increased from 35 mm to 60 mm to accommodate larger vacuum chambers for the IR beamlines.

10 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 Dipole Sextupole SR Magnets Quadrupole Reference designs are being developed to meet the field quality requirements, stability and chamber geometry constraints. R = 20 mm

11 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 Precise Magnet Alignment by Vibrating Wire Procedure Support magnets on temporary support brackets resting on cam movers (or X-Y translation stages) Align all components (magnets, chamber, wire) by a laser tracker to within 100 μm. Align for roll angle using inclinometers and cam movers. Adjust vertical position of the wire for the specific magnet to be aligned. Align and lock the magnet. Remove temporary supports.

12 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 SPring-8 Alignment Positioning and Alignment of the SR Magnet-Girder Assembly Positioning by Air Pads (IHEP)The magnet-girder assemblies in the tunnel will be transported by a tug transporter. The assemblies will be positioned on removable alignment mechanisms (not shown) using air pads. Threaded rods on each side of the girder are to be in their respective slots. After final alignment with a laser tracker, double nuts with spherical washers will be tightened on the threaded rods.

13 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 Vibration - Ambient Ground Motion At the CFN floor rms (2-50 Hz) horizontal and vertical displacements are 30nm and 32 nm, respectively. The CFN concrete floor thickness is inch. Vertical Displacement Magnet stability tolerances (S. Kramer) Random motion, rms (dx,dy) < (330nm, 23nm)

14 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 PSDs of Vertical Ambient Motions at Light Sources Additional site vibration measurements are planned to verify present results and to identify local sources of excitation in and around the NSLS building.

15 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 Magnet Vibration due to Ambient Ground Motion Ambient ground motion drops steeply as 1/ω 4 No significant vibration amplification for ω/ω n << 1 First natural frequency of the girder-magnet assembly should be above 30 Hz. Seryi [2003]

16 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 Natural Frequencies and Mode Shapes SR Magnet–Girder Assembly Rolling Mode, f 1 = 68.7 HzTwisting Mode, f 2 = 94.3 Hz Bending Mode, f 3 = Hz

17 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 Thermal Stability Air and process water temperature regulation: ± 0.1ºC  α (expansion coefficient). L (beam height). ΔT (change in temperature) 12(μm/m.ºC). 1 (m) (± 0.1 ºC) ═ ± 1.2 μm Magnet Stability Requirements are presented by S. Kramer. Air-conditioning ducts from a single mechanical room will cover 6 cells (130m). Therefore, magnet stability tolerance limit for a plane wave of < 3 Hz ( wavelength ~ 100M) can be used: RMS vertical displacement of the quadrupoles < ± 2μm

18 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 Thermally-Insulated NSRRC Girder Thermal Stability (Contd.) LCLS Support Stand If necessary, the girders can be insulated to reduce ΔT by a factor of ~ 2.

19 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 SR Absorbers Chamber 2 Counter-Flow Absorber Flange Absorber Crotch Absorber Ray-Tracing RF Spring

20 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 SR Crotch Absorber – FE Thermal Analysis The crotch absorber intercepts 814 W at a normal peak power density of 0.25kW/mm 2. A maximum temperature of ºC is calculated.

21 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 SR Wiggler Absorber Wiggler Absorber The wiggler absorber clips the radiation fan by about 1 mrad on each side to shadow the downstream exit port. The total intercepted power is 11.6 kW out of 64.6 kW. The absorber is cantilevered from the upstream flange to allow thermal expansion during bakeout. Glidcop

22 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 Maximum temperature (ºC) 397 Cooling wall temperature (ºC) 187 Maximum von Mises stress (MPa) 427 SR Wiggler Absorber – FE Thermal Analysis About % of the incident power is reflected or scattered. Therefore, the maximum surface temperature is expected to be less than 337ºC.

23 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 Thermal Fatigue Tests at APS (26-ID Beamline) Realistic design criteria have been established based on thermal fatigue tests at ESRF and APS: For Glidcop intercepting an ID beam, thermal fatigue life at 400ºC is estimated to be > 30,000 cycles.

24 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 Tentative Locations of the Scrapers:  One horizontal scraper (HS-A) in the dispersive section to acquire energy distribution of the electron beam. This scraper may have only one (inboard) blade.  One horizontal scraper (HS) in a straight section with zero dispersion in order to have information on the transverse size of the electron beam  Two vertical scrapers (one upstream of the injection straight and another downstream of it) to shadow ID poles from electro- magnetic shower. SR Beam Scrapers HS-A HS VS (1) VS (-1)

25 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 SR Beam Scrapers - Design Vertical Beam ScrapersBeam Scrapers with Large Blades Studies are underway to find the best available locations for the scrapers and to optimize their blade geometry. Their role in protecting the ID magnetic structures will be investigated.

26 BROOKHAVEN SCIENCE ASSOCIATES S.Sharma 10/11/2006 Concluding Remarks Reference designs are being developed for the booster and SR magnets that will meet field requirements, stability and geometry constraints. A vibrating wire technique will be used to meet the precise (30 μm) alignment tolerance for SR magnets. An R&D program will be initiated to design and test the alignment hardware/software. The design of SR magnet-girder assemblies will ensure that vibration stability requirement will be easily met. Thermal stability requirements are likely to be met with the tunnel air temperature control of ± 0.1ºC. Conceptual designs of the SR wiggler and crotch absorbers have been developed. Beam scrapers are being investigated for their optimum locations and designs, and for their contribution towards protecting IDs from EM shower.