Download From meters of clay to nanometers of optical stability.

The MAX IV stability approach – From meters
of clay to nanometers of optical stability.
Brian Norsk Jensen, MAX IV Laboratory, 2015
Outline
● Aspects on Mechanical Stability
– Correlated Motions
– Reminder on Illustrative School Book Example
● The MAX IV Stability Criterion
– Accelerator Stability leading to Vibration Level Goal
– Design Goals for Facility Components
● Examples, Results and Practices
–
–
–
–
Design and Characterization of Soft X-Ray Mirror Units
Ring Magnet Stability
Soft X-Ray Monochromator
Other Examples
● Conclusions
2
Brian Norsk Jensen, 2nd Swedish-German Workshop on X-Ray Optics, Berlin 28-30 April 2015
Correlated Motions
● We are mainly concerned about Relative Displacements
●
● Sensitivity to Vibrations can be Reduced by increasing Correlation
● The MAX IV Floor is the “Backbone” of our Machines and Beamlines
● Stable Supports Ensure Correlated Motions (in Phase)
● 20nm-30nm RMS, 𝐢𝐧𝐭𝐞𝐠𝐫𝐚𝐭𝐞𝐝 𝐟𝐨𝐫 𝐟>𝟓𝐇𝐳
(originating from storage ring considerations)
Illustrations:
http://upload.wikimedia.org/wikipedia/commons/1/17/Ship_wave_bending.svg
http://commons.wikimedia.org/wiki/File:Rotating_earth_axial_tiles_to_orbit.gif
3
Brian Norsk Jensen, 2nd Swedish-German Workshop on X-Ray Optics, Berlin 28-30 April 2015
The MAX IV “Boat”
Shear Wave Velocities
Concrete, 0.3m, >2400 m/s
Stabilized UGM, 0.3m, 1300 m/s
Low Baltic Clay Till,
2-8m layer,
250-300 m/s
North-East Clay Till,
8-13m layer,
400-650 m/s
Lime Stabilized Soil,
4m in average, >900m/s
Large Footprint, No Isolated
Foundations for Roofs etc.
Poisson’s Ratio = 0.48
Shale/Mudstone,
1100-1200 m/s
www.ekdahlgeo.se
4
Brian Norsk Jensen, 2nd Swedish-German Workshop on X-Ray Optics, Berlin 28-30 April 2015
Stability Management Starts with Newton
𝑚𝒙 =
𝑭
Vibration Isolation
Stable Supports
Issue
Oscillating Force
Floor Vibrations
Effect
Transfer of Force
Component Vibration
𝐹0 sin 𝜔𝑡
Vibration
Isolation
𝑚𝒙 + 𝑐𝒙 + 𝑘𝒙 = 𝐹0 sin 𝜔𝑡
FT sin 𝜔𝑡 + 𝜃
Stable
Supports
(Vibrations of the Mass)
x = X sin 𝜔𝑡 + 𝜃
𝑚𝒙 + 𝒄 𝒙 − 𝒚 + 𝒌(𝒙 − 𝒚) = 0
(Floor Vibrations)
y = Y sin 𝜔𝑡
5
Brian Norsk Jensen, 2nd Swedish-German Workshop on X-Ray Optics, Berlin 28-30 April 2015
Transmissibility
Transmissibility
4
160
Damping ζ=c/cc
3
140
0.0025
Phase Shift [deg]
Transmissibility
Phase Shift
180
0.1
0.15
2
0.25
0.375
0.5
1
120
100
80
60
40
1
20
0
0
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
0
1
Frequency ω/ωn
Vibration Isolation
Stable Supports
1/3 Octave value [mm]
10
6
10
10
10
10
Pos north, dir vert - design spektrum
17 Events i tidsperioden 02-07 Januar 2011
Rød linje - snittspektra
rms = 86.7 nm (5-100Hz), 86.8 nm (1-100Hz)
-3
Stable Supports
-4
-5
-6
-7
-8
Brian Norsk Jensen, 2nd Swedish-German
Workshop on X-Ray Optics, Berlin 28-30 April 2015
10
10
0
10
1
1/3 Octave frequency [Hz]
10
2
2
3
Frequency ω/ωn
4
5
Transmissibility of a Mechanical System
FEA: 112Hz
Measurements: 95Hz
Transversal Measurements
Calculations by Karl Åhnberg
7
FEA: 119Hz
Measurements 100-120Hz
Brian Norsk Jensen, 2nd Swedish-German Workshop on X-Ray Optics, Berlin 28-30 April 2015
MAX IV Ring Magnet, U3
Measurements 39Hz
Calculations by Karl Åhnberg.
Measurements and analysis by
Curt Preissner and Jeffrey Collins,
APS, Argonne
8
Brian Norsk Jensen, 2nd Swedish-German Workshop on X-Ray Optics, Berlin 28-30 April 2015
FEA: 55Hz
Measurements: Curt Preissner, APS
9
Brian Norsk Jensen, 2nd Swedish-German Workshop on X-Ray Optics, Berlin 28-30 April 2015
Fixing Supports to the Floor
10
Brian Norsk Jensen, 2nd Swedish-German Workshop on X-Ray Optics, Berlin 28-30 April 2015
Examples Stable Supports/Structures
Calculations: Karl Åhnberg
11
Brian Norsk Jensen, 2nd Swedish-German Workshop on X-Ray Optics, Berlin 28-30 April 2015
Examples Vibration Isolation
12
Brian Norsk Jensen, 2nd Swedish-German Workshop on X-Ray Optics, Berlin 28-30 April 2015
FEM Calculations on Buildings
Calculations:
Peter Davidsson,
CreoDynamics.com
13
Brian Norsk Jensen, 2nd Swedish-German Workshop on X-Ray Optics, Berlin 28-30 April 2015
Some Other Thoughts
System
Low Inertia
High inertia
Stiff
Stable Supports,
Self-supporting Magnets
Internally Cooled Optics,
Facility Floors
Soft
Acoustical Damping?
Dissipation of Energy?
Vibration Isolating Systems,
Cooling Media Pulsations
● Viscoelastic Materials / Dynamic Stiffeners
● Tuned Oscillator (ω=constant)
● Active Control ( ω/ωn<0.5 or so)
● ...
14
Brian Norsk Jensen, 2nd Swedish-German Workshop on X-Ray Optics, Berlin 28-30 April 2015
Conclusions
● Stability Management is mainly about Reduction of Sensitivity
– Adding Stiffness
– Civil Engineering
– Stable Support/Structures/Mechanisms
● Vibration Isolation should be done at the Sources
● Predicting Vibration Levels by FEA is Difficult Business
● Measurements is a Good Tool for Adjusting Calculations
– Full Modal Analysis is Fantastic, when possible
– Transmissibility Measurements
● Non-discovered Land Somewhere? (At least to me)
– So Much Fun, So Little Time…
15
Brian Norsk Jensen, 2nd Swedish-German Workshop on X-Ray Optics, Berlin 28-30 April 2015
Thank You!
● With help from
– Karl Åhnberg, MAX IV
– Curt Preissner, APS
– Jeffrey Collins, APS
– Help and Fruitful Discussions with People at the Faculty of Engineering in Lund
– People from the Construction Company and its Consultants
16
Brian Norsk Jensen, 2nd Swedish-German Workshop on X-Ray Optics, Berlin 28-30 April 2015