# Presentation: 516751

## Conventional Facilities & Beam Stability

**Marty Fallier**
**Director for Conventional Facilities**
**NSLS-II Beam Stability Workshop**
**April 18, 2007**

## 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
- +/- 0.1o C  for 1 hour time constant
- Thermal stability of experimental floor
- +/- 0.5o C  for 1 hour time constant

## NSLS II Facility Overview

**Access Tunnel**

**LOB (1 of 5)**

**JPSI**

**NSLS**

**CFN**

**BLOC**

**NSLS II**

**Service Bldgs (1 of 5)**

## NSLS II Facility Overview cont’d

**NSLS II Floor Plan**
- BLOC – Booster/LINAC/ Operations Center
- LOB – Lab Office Buildings (3 base scope up to 5 future)
- Service Buildings (5)
- RF Area
- Tunnel Area
- Electrical Mezzanine
- Experimental Floor
- Access Corridor

**1**

**4**

**3**

**2**

**2**

**2**

**2**

**2**

**3**

**3**

**3**

**3**

## NSLS II Facility Overview cont’d

**Access Corridor**

**Lab-Office Bldg**

**SR Tunnel**

**Experimental Floor**

**Service Bldg 1****st**** Floor**
**(earlier concept)**

**7**

**5**

**8**

**6**

**Electrical Mezzanine**
**(above tunnel)**

## 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

## 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

## 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

## Tunnel Design - Ring Building Section

**Non-vibrating Equipment**

**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**

**Rotating Machinery**

**Distance determined by modeling & empirical analysis**

## 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

## 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**

## Temperature Stability

- Key temperature stability requirement is tunnel air @ +/- 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

## 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