1 BROOKHAVEN SCIENCE ASSOCIATES Conventional Facilities & Beam Stability Marty Fallier Director for Conventional Facilities NSLS-II Beam Stability Workshop April 18, 2007

2 BROOKHAVEN SCIENCE ASSOCIATES Stability Dependent on Conventional Facilities Stability goals driven by conventional facility design Stability of storage ring tunnel floor Vibration < 25 nm PSD from 4-50hz Stability of experimental floor Vibration level of < 25 nm PSD from 4-50hz for general floor area Vibration level for 1 nm resolution beam lines requires further definition but appears achievable with proper correlation Thermal stability of storage ring tunnel environment +/- 0.1 o C for 1 hour time constant Thermal stability of experimental floor +/- 0.5 o C for 1 hour time constant

3 BROOKHAVEN SCIENCE ASSOCIATES NSLS II Facility Overview Access Tunnel LOB (1 of 5) JPSI NSLS CFN BLOC NSLS II Service Bldgs (1 of 5)

4 BROOKHAVEN SCIENCE ASSOCIATES NSLS II Facility Overview cont ’ d NSLS II Floor Plan 1. BLOC – Booster/LINAC/ Operations Center 2. LOB – Lab Office Buildings (3 base scope up to 5 future) 3. Service Buildings (5) 4. RF Area 5. Tunnel Area 6. Electrical Mezzanine 7. Experimental Floor 8. Access Corridor

5 BROOKHAVEN SCIENCE ASSOCIATES NSLS II Facility Overview cont ’ d Access Corridor Lab-Office Bldg SR Tunnel Experimental Floor Service Bldg 1 st Floor (earlier concept) Electrical Mezzanine (above tunnel)

6 BROOKHAVEN SCIENCE ASSOCIATES CF Program for Vibration Management Assessment of “ green-field ” conditions Studies by Colin-Gordon Associates & N. Simos On-going monitoring program Identification and mitigation of cultural sources (where feasible) FE Modeling of site and facility design Needed to understand & predict facility response Design optimization tool Analysis of other facilities (CFN, APS & SPring 8 thus far) Draw upon lessons learned Provide input for model Model performance verification During & after construction, implement monitoring and maintenance program

7 BROOKHAVEN SCIENCE ASSOCIATES Specific Vibration Mitigation Strategies “ Monolithic ” slab for accelerator and experimental floor Slab thicknesses based on vibration modeling results Possible use of polymer admixtures and concrete layering for enhanced damping characteristics (access corridor & service bldgs) Isolation of bldg structure, access corridor and mechanical spaces from tunnel and experimental floor slab Inertia bases and isolation of piping, ducts and machinery from tunnel and experimental floor slabs Low flow velocity design for ducts and piping Specification and commissioning of equipment and systems to include precision alignment, balancing & vibration measurement Orientation of service bldgs to maximize distance of machinery sources from tunnel and experimental floor slabs

8 BROOKHAVEN SCIENCE ASSOCIATES Ring Building Section Ratchet or Shield Wall Electrical Mezzanine Bldg structure Isolated from tunnel and experimental Floor Earth Shield Berm Experimental Floor Access Corridor Tunnel Floor “ Monolithic Joint ” Isolation Joint Isolation Joint or Void Space Tunnel Roof Isolated Pier for Column Isolated Grade Beam

9 BROOKHAVEN SCIENCE ASSOCIATES Tunnel Design - Ring Building Section Non-vibrating Equipment Need to assure that vibration mitigation measures are carried out at Ring building interfaces with other structures and where systems enter building or tunnel Section at Lab Office Building and Service Building Rotating Machinery Distance determined by modeling & empirical analysis

10 BROOKHAVEN SCIENCE ASSOCIATES Vibration Studies Studies of NSLS II “ green field ” conditions indicate an existing cultural vibration level of ~20 nm Does not factor in reduction due to expected filtering effect of slab Does not factor in cultural vibration reductions that can be achieved Does not factor in addition from self-inflicted sources Additional modeling and analysis is on-going to predict the value of these factors to arrive at an expected value for NSLS II N. Simos will present in-depth discussion of modeling analysis and initial results in breakout session

11 BROOKHAVEN SCIENCE ASSOCIATES Service Bldg Results Concern about location of rotating machinery in service buildings near tunnel when positioned on infield side of Ring Bldg Initial results show contribution from service bldg is minor (0.4nm) if source is properly isolated and located ~30 ft from tunnel Additional mitigation can be applied to reduce energy transfer to ground beneath service building and reduce contribution even further Conclusion – service building, and associated economy for utility routing, in infield appears workable 30 ft

12 BROOKHAVEN SCIENCE ASSOCIATES Temperature Stability Key temperature stability requirement is tunnel +/- 0.1C (+ /-.18 F) at any given location over 1 hour Key parameter is temperature stability and repeatability vs. absolute accuracy. This level of stability has been achieved at other facilities and BNL has achieved even better stability in microscopy lab applications The relatively steady state heat load and the high thermal mass of the tunnel make this quite achievable Thermal modeling will be performed to confirm concepts and optimize system design

13 BROOKHAVEN SCIENCE ASSOCIATES CF Beam Stability Path Forward Continue vibration study and modeling to provide added assurance that design will yield desired performance Assess impacts of proposed NSLS II design choices and equipment on vibration environment Optimize vibration resistant design vs the quantity of concrete & steel in the tunnel and experimental floor slabs to contain costs Identify local sources of vibration from on-site/off-site operating facilities to enable remediation (i.e. repair roads, balance machinery etc.) and optimize operating environment for NSLS II Continue collaboration with other facilities to understand vibration performance and verify model accuracy Perform thermal modeling to confirm stability goals can be achieved