Survey of the Fermilab NOvA Detectors Babatunde O’Sheg Oshinowo and Horst Friedsam Fermi National Accelerator Laboratory, Batavia, Illinois, U.S.A.
NOvA Detectors NOvA Detector Module The NOvA Experiment Far Detector Site
NOvA Far Detector Building NOA: NuMI Off-Axis e Appearance Experiment Ash River e = electron neutrino • A 14 kton Far Detector at a distance of 810 km from the NuMI Target • North America's most advanced neutrino experiment (Completed at Ash River in July 2014) • The NOvA project includes accelerator upgrades to bring • A 0.33 kton Near Detector identical to the NuMI (Neutrino at Main Injector) beam intensity the Far Detector at a distance of 1 km from 400 kW to 700 kW from the NuMI Target NOvA detectors are constructed from planes of • Uses two detectors to look for changes in the neutrino (Completed at Fermilab in February 2014) beam as it travels: PVC modules Far Detector in Ash River, Minnesota • An 0.22 kton prototype NDOS Extrusions have a cellular structure, with 16 Near Detector at Fermilab (Near Detector On the Surface) isolated cells per extrusion • The NOvA detectors are sited 14.6 mrad off the center of identical to the Near Detector sited A module of 32 cells is constructed from two 16- the NuMI beam axis on the surface 107 mrad off the NuMI cell PVC extrusions glued together beam axis at Fermilab (Completed in 2010 • Mostly active liquid scintillator Near and Far Detectors and L = 15.6 m for Far Detector and operated till January 2013) PVC plastic L = 4.2 m for Near Detector • This site is at 810 km from Fermilab, about 11.8 km Each cell contains liquid scintillator and light • Full operation began in October 2014 off-axis from NuMI beam measuring fiber optics • Scheduled to Run at least till 2021 • The Ash River site, near Canadian border, is the PVC Module farthest available site from Fermilab in the U.S. Modules are capped by a Manifold and an End Cap = Module Plane along the NuMI beamline to contain the liquid volume
NOvA Near Detector Block NOvA Far Detector Block NOvA Far Detector NOvA Detector Module • Far Detector (FD) consists of 28 blocks: • 32 planes make 1 NOvA block for Far Detector Completed Block • 24 planes make 1 NOvA block for Near Detector FD B B B B B B ……..B B B B B • NOvA Detector is constructed from alternating planes of • NOvA Far Detector block (B) configuration is as follows: in Assembly Area 0 1 2 3 4 5 23 24 25 26 27 vertical and horizontal PVC extrusion modules, connected • NOvA Near Detector block (B) configuration is as follows: where the number of blocks is counted 0 through 27 B = h v h v h v h v h v h v h v h v together by glue between planes 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15… NovA Horn 2 ...h16v17h18v19h20v21h22v23h24v25h26v27h28v29 h30 v31 B = h0v1h2v3h4v5h6v7h8v9h10v11h12v13h14v15h16v17h18v19h20v21h22v23 • Each block is 15.6 m wide by 15.6 m high by • 12 extrusion modules are glued together side by side on a 2.141 m thick. flat assembly table to form one plane (or layer) of the Far where v are vertical planes and h are horizontal planes of modules; where v are vertical planes and h are horizontal planes of modules; number of planes is counted from 0 through 31 Detector number of planes is counted from 0 through 23 • The PVC in a 32-plane block weighs 177.7 metric tons • 3 extrusion modules are glued together for the Near • Block assembly starts from plane-31 (v31) on • Block assembly starts from plane-23 (v23) on the assembly Detector the assembly table and ends with plane-0 (h0) table and ends with plane-0 (h0) • The weight of a 32-plane block is 487.5 metric tons Modules when filled with liquid scintillator • All planes in each block are glued together in a horizontal • All planes in each block are glued together in 14 kton total mass a horizontal orientation on a block assembly table orientation on a block assembly table • Far Detector consists of 896 planes 9 kton liquid scintillator 5 kton PVC plastic NOvA Far Detector Building NOvA Near Detector NOvA Near Detector Cavern Far Detector Block Assembly Fermilab Plan view Detector Hall Assembly Table • Block assembly starts at the glue machine where glue • The Near Detector (ND) consists of 8 blocks: At Ash River, MN Glue is applied to the extrusion modules Machine Pivoter • Modules are then transported to the assembly table ND B0B1B2B3B4B5B6B7 Holometer by the vacuum lifting fixture to be glued to the next where the number of blocks is counted 0 through 7 modules to form planes (layers) • Block assembly starts in the horizontal position from Module • Near Detector similar to the Far Detector • Each block is 4.2 m wide by 4.2 m high by 2.136 m thick Detector Cavern plane-31 (v31) on the assembly table and ends with plane-0 (h ). • Located on the Fermilab site about 1 km 0 Alignment Post • The PVC in a 24-plane block weighs 5 metric tons from the NuMI target • 20.4 m wide by 113.8 m long with the detector section sunk 16 m below the existing grade into granite rock Vacuum • The weight of a 24-plane block is 13.75 metric tons • Cavern is 105 m underground adjacent • The Block Assembly area houses the NOvA Block Pivoter at the site Lifting Fixture 0.33 kton total mass to the MINOS access tunnel, downstream machine and the Assembly Table that is used to build all when filled with liquid scintillator • Detector Hall at the south end 0.21 kton liquid scintillator of the MINOS shaft the blocks 0.12 kton PVC plastic • Block Assembly area at the north end Module • The NOvA Near Detector consists of 192 planes • The cavern is 6.0 m wide by 20.5 m long • Each block is assembled on the assembly table while it is by 6.0 m high in its horizontal position • The Detector Hall will house all the 28 NOvA blocks Far Detector Block Assembly Far Detector Plane Measurements Near Detector Plane Measurements Far Detector Block Assembly Table Survey
• Groove measurements on Block will be made • The surface of each module plane of the • Block Assembly Table surface measured with at specified locations by placing the SMR where NOvA Block is scanned with the HDS6100 the API Tracker using 61 cm x 61 cm grids • Once a block has been finished, the Pivoter is used to the horizontal module grooves intersect the Scanner located on the ceiling inverted move the block into place within the detector building to Dark Energy Camera Telescope extreme end of the vertical plane the south wall directly above the Pivoter Assembly Table • Measurements made with the Table in the horizontal position using the API Laser Tracker Laser Scanner • The bottom of the SMR will sit in the horizontal • It then pivots 90° to set the block upright to the ideal Overall Block Survey Tolerance: groove while the one side of the SMR touches the location • Relative 2 mm (Horizontal) edge to edge; • Measurement results are used for shimming Pivoter Transporting vertical plane • The block is then filled with Liquid Scintillator • Relative 0.75 mm or better (Vertical) the Table surface before block installation Block in Detector Hall between adjacent module pieces • SMR will be placed on every third groove from • Angular tolerance of ± 2 mm/15.6 m • Surface elevation differences range the left (-13) and right (+13) edges of the = ± 0.13 mrad from -20 mm to 30 mm module, and on the middle groove (0) Far Detector Surface Geodetic Network Detector Hall Control Network Far Detector Block Survey Far Detector Block Survey
• Established a GPS surface geodetic control network that • AT401Tracker on a wall bracket mounted Ash River Surface Network SMR at 70 cm connects points at Fermilab to Ash River Lower Level up near the ceiling of the Far Detector hall above Target • Block0 and Block1 surveyed with and Upper Level without filled liquid scintillator • Tie surface control network to the National Geodetic • Measurements made with AT401 Tracker • Block2 through Block6 surveyed with Survey’s Continuously Operating Reference Stations (CORS) using a vector target with SMR at both 50- precision geodetic network • Established a precision control network •Tied the new building control network to the cm and 75-cm above target on extension filled liquid scintillator in the Far Detector building for positioning surface network using the Geodimeter Total rods. The Rods were attached to block SMR • Block7 through Block12 surveyed • All long baselines are known to better than 1 cm horizontally the Far Detector using the API Laser Tracker Station targets glued on the block. The two without filled liquid scintillator and vertically measurements at each target were used • Block13 through Block27 surveyed with • Extended control network on the four levels of • Precision control network in the Near Detector for vector computation filled liquid scintillator • The network based on the NAD83 (North American Datum the west wall of the Detector hall using the Cavern just completed using the API Tracker Vector Target • Survey was completed in March 2014 1983) for horizontal datum and the NAVD88 (North AT401 Tracker • Each block has 8 targets – 4 on the Top, 2 SMR at 50 cm American Vertical Datum 1983) for vertical datum on the West side and 2 on the East side above Target Near Detector Block Survey Near Detector Block Survey NOvA Neutrino Experiment Results Acknowledgment
We would like to thank • As-Built survey of the 8 Near Detector blocks was performed • Block0 through Block7 surveyed with and without filled liquid scintillator • Alignment and Metrology Department members who participated in the NOvA Detector survey, • Measurements were made with API Radian Laser especially Gary Crutcher and Chuck Wilson Tracker using SMR on 50-cm extension rods • Survey was completed in March 2014 attached to block targets glued on the block • Dr. Pat Lukens and Dr. Ting Miao of the NOvA NOvA's new neutrino oscillation physics Collaboration • Each block has 8 targets – 4 on the Top, 2 on the results are presented at Neutrino2016 in West side and 2 on the East side London on July 4, 2016. https://www-nova.fnal.gov/