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Size: 993
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← Revision 6 as of 2018-01-04 02:24:27 ⇥
Size: 1697
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| Each in-vacuum optical table for the 40m test masses is an optical breadboard with the diameter of 38inch. We plan to place a single stage suspension system for a platform breadbaord. |
Each in-vacuum optical table for the 40 m test masses is an optical breadboard with a diameter of 38 inches. We plan to place a single stage suspended breadboard on top of this existing table to get 1 additional stage of seismic isolation. We will need 4 of these to cover each test mass. |
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| * constrained layer damping of blade modes ? * What about just using 3 little coil springs to mount the breadboard from underneath rather than use blades? Then its more like an extra layer of the stack. |
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| * Vibration isolaiton * Requirement |
* Vibration isolation * Requirement: 30x reduction for f = 10-100 Hz * pendular modes should be 0.2-0.45 Hz or 1.5-2.5 Hz to avoid SOS resonances. |
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| * does it need to be active or can we use resonant eddy current damping? | |
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* Active VS Passive approach * Active * Pros * ... * Cons * ... * Passive * Pros * ... * Cons * ... |
Optical Platform Suspension
Each in-vacuum optical table for the 40 m test masses is an optical breadboard with a diameter of 38 inches. We plan to place a single stage suspended breadboard on top of this existing table to get 1 additional stage of seismic isolation. We will need 4 of these to cover each test mass.
- VOPO style suspension
- Attach a structure (poles or a frame) on the existing breadboard
- The structure supports vertical blades
- Wires are attached on the vertical blades
- A breadboard is suspended from the vertical blades
- Breadboard
- Thickness
- Internal resonances: modes/frequencies
- Blade spring
- Load weight (total weight of the load, max load)
- constrained layer damping of blade modes ?
- What about just using 3 little coil springs to mount the breadboard from underneath rather than use blades? Then its more like an extra layer of the stack.
- Counter balance
- Vibration isolation
- Requirement: 30x reduction for f = 10-100 Hz
- pendular modes should be 0.2-0.45 Hz or 1.5-2.5 Hz to avoid SOS resonances.
- Active control
- Sensor (What, how many, how sensitive, range, noise)
- Actuators (Coil Magnet, requirement, strength, Vertical, Horizontal )
- Electronics (Feedthru)
- Control system
- does it need to be active or can we use resonant eddy current damping?
- Utility structures
- EQ stops
- Safety (Blades/Wires)
- Active VS Passive approach
- Active
- Pros
- ...
- Cons
- ...
- Pros
- Passive
- Pros
- ...
- Cons
- ...
- Pros
- Active