Workshop on Tau-Charm at High Luminosity Alignment M. Del Franco, E. Di Pasquale, S. Tomassini La Biodola, Isola d'Elba (Italy) 27-30 May 2013

CONTENTS Project Footprint Mission Tollerances and alignment implications State of the Art Alignment Network, Design & Survey Simulation & Analysis Conclusions

Preliminary FOOTPRINT

MISSION All measurement tasks require a fixed reference base (or datum) from which measurements can be made and calculated. For large-volume metrology applications, the reference base typically takes the form of a survey network that consists of a collection of target "nests" and/or instrument stations that have known geometry and uncertainty. The survey networks will cover the whole of the site, providing a global coordinate matrix for alignment and dimensional control. The accuracy requirements for each network vary according to the alignment tasks for which they are designed.

Alignment TOLERANCES? The required positioning tolerances are the key point of the survey and alignment network design. Those tolerances dictate the instruments and methods necessary to obtain the positioning goals. As an examples the NSLS II tolerances are shown. Relative tolerances Girder to Girder Magnet-to-Magnet Horizontal positioning ± 0.15 mm ± 0.03 mm Vertical positioning Longitudinal ± 0.50 mm ± 0.1 mm Roll angle ± 0.5 mrad ± 0.20 mrad Table 1: NSLS-II Girder-to-Girder and magnet-to-magnet Positioning Tolerances. Global tolerances ± 3 mm Horizontal positioning Vertical positioning Table 2: NSLS-II Required Global Tolerances. A similar table is expected from the -charm collaboration to design a dedicated alignment network

Let’s have a look on what has been done all around the world on the survey and alignment network design

J-PARC Japan Proton Accelerator Research Complex STATE OF THE ART Circumference 518,4m J-PARC Japan Proton Accelerator Research Complex Survey network GPS Circumference 3.9 miles (6.3 km) TPS Taiwan Photon Source

NSLSII National Synchroton Light Source II FERMILAB Fermi National Accelerator Laboratory NSLS-II covers an area of about one-eighth of a square kilometer with a radius of ~124 m and a circumference of ~780 m.) Circumference 3.9 miles (6.3 km)

Alignment NETWORK DESIGN & SURVEY We plan to set an alignment network along the accelerator tunnel. The alignment network is used as a reference for installing，locating or adjusting the accelerator devices. It can also be used to monitor the deformation of the accelerator alignment along with time. According to the major structure of the accelerator complex, the network can be divided into Primary Control Network 8 Monuments (Surface Network) 103 meters above sea level Scondary Control Network 15 Sight Risers (Tunnel Network) 94 meters above sea level The storage ring and linac monuments are accessible through penetrations in the roof wall shielding, Sight Risers

Primary Control Network Survey Two receivers Three receivers Seven receivers

Secondary Control Network Survey

Secondary Control Network Survey cont’ Monument section layout of a tunnel alignment network Survey scheme of an horizontal section

Instruments available @ LNF SURVEY & ALIGNMENT Instruments available @ LNF Laser Trackers Leica LTD 840 (±15µm+6µm/m) Leica LTD 500 (±10µm/m) Optical Instruments 2 Leica T3000 theodolites 2 Leica N3 levels Hall Probe & Rotating Coil Magnetic measurements for component fiducialization Stretched wires (WPS)

-charm case study Primary Network Secondary Network Only the outer reference points of the secondary network are visible.

Alignment network SIMULATION and ANALYSIS A wide range of metrology systems will be used during the assembly of the Tau-Charm machine such as laser trackers, total stations, which will interface with dedicated software packages and measurement plans specific to the Tau-Charm requirements.

VERY PRELIMINARY pREANALYSIS Number of Entered Stations = 23 Number of Azimuth/Bearing Observations (DMS) = 197 Number of Zenith Observations (DMS) = 29 Number of Distance Observations (Meters) = 36 Number of Angle Observations (DMS) = 29 VERY PRELIMINARY

Network Design Evolution @ Fermilab Full Network Preanalysis GPS+LT+Traverse+Levels

Vibration Tolerances SuperB Request (RMS vertical displacement for SuperB) Measured @ Tor Vergata (RMS vertical displacement) IP 300 nm 20-40 nm Final Focus 20-30 nm Arcs 500 nm Elsewhere 1000 nm

Instrumentations and Techniques Conclusions Lattice In order to obtain congruence between the survey network and the lattice layout provided by the machine physicist, the datum of both of these systems must be the same. The six parameters (x, y, z, yaw, pitch, and roll) provided by the lattice for each beam component must be used for all calculations to set the girders and other accelerator components. The database also contains the fiducial information of each component that needs to be placed. Civil Infrastructure Civil Infrastructure is closely related to Lattice and Machine tolerances. Instrumentations and Techniques Some specific tools or techniques may be taken into considerations in order to fulfill the alignment requirements Hydrostatic alignments Stretched Wire Systems Vibrating wires fiducialization Micro/nano positioning……..and so on

Thank you