DUNE ND Hall Study Mike Wilking @ Stony Brook Luke Pickering and - PowerPoint PPT Presentation

DUNE ND Hall Study Mike Wilking @ Stony Brook 
 Luke Pickering and Dan Douglas @ Michigan State

ND Hall Size Requirements 
 Option B: Existing + 50% • Working conceptual layout for the hall over the past year was 55 140 ft ft “long” (beam-direction) x 140/120 ft (= 42.7/36.6 m) “wide” (o ff -axis direction) 55 ft +$5M • This is the +50% option that was agreed upon by the ND 120 ft group in March, 2017 (although 90° rotated relative to the beam initial proposal) DUNE-PRISM 0.5 GeV • Original DUNE-PRISM goal was to make measurements up to ~33 m o ff -axis 30 m • But this must include non-fiducial LAr & cryostat width, etc. • May also need additional width near on-axis position for magnet infrastructure • Language in ND Report Recommendation: 
 33 m R6) The experimental floor area must be at least 35 m × 17 m and the hook height must be at least 13 m, measured from the floor. • Note: “experimental floor area of 35 m…” 
 rather than “LAr FV reach of 35 m…”

How Far Off-Axis? • Further o ff -axis = lower reach in neutrino energy • 500 MeV flux peaks at 26 m o ff -axis (GeV) 2 • To understand events at 500 MeV, we need access FHC ν µ ν lower energies at further o ff -axis positions Peak, 1.5 RHC ν E µ • One method to determine the lowest needed energy is to 1 construct a Gaussian energy spectrum at 500 MeV (10% width) using linear combinations of o ff -axis fluxes 0.5 • This is not the only method one could employ (see next 0 slides), but it should provide some useful information 5 10 15 20 25 30 35 40 Off axis position (m) • The 500 MeV Gaussian fit clearly begins to degrade when fluxes between 30 m & 33 m are excluded (GeV) (GeV) 12 12 − 12 − 12 − − 10 10 × 10 × 10 × × (A.U.) (A.U.) (A.U.) (A.U.) Fluxes up to 33 m Fluxes up to 35 m Fluxes up to 25 m Fluxes up to 30 m 20 20 20 20 ν ν ν ν Φ Φ Φ Φ 10 10 10 10 0 0 0 0 0 0.5 1 1.5 0 0.5 1 1.5 0 0.5 1 1.5 0 0.5 1 1.5 E (GeV) E (GeV) E (GeV) E (GeV) ν ν ν ν 12 12 − − 10 10 (A.U.) (A.U.)

Oscillated Flux Fits • We can also use linear combinations of o ff -axis fluxes to construct an oscillated flux seen at the far detector for any currently allowed set of oscillation parameters • Again, this is not the definitive metric, but it does show how well such a fit can resolve the bump below the 2nd oscillation maximum (which peaks as − 12 10 × 30 low as ~500 MeV, depending on Δ m 322 ) per POT) 2 2 -3 2 sin ( ) = 0.5, m = 2.6 10 eV θ Δ × 32 23 Fluxes up to 40m 20 • The following studies probe the 9 points -2 cm Fit region -1 in Δ m 322 , θ 23 space shown in the top figure (GeV 10 ν Φ • Vary o ff -axis range used in fits 0 ND - FD (osc.) 0 1 2 3 4 5 6 0.5 FD (unosc.) 0 • The next few pages show many such fits 0.5 − 0 1 2 3 4 5 6 E (GeV) ν

Fluxes Up to 40 m Off-Axis • Can even somewhat resolve the peak below the 3rd oscillation maximum for all values of Δ m 322

Fluxes Up to 35 m Off-Axis • Can still generally resolve bump below 2nd oscillation maximum for all values of Δ m 322 , although some fluctuations are seen in the ratio to the unoscillated flux

Fluxes Up to 33 m Off-Axis • Can still generally resolve bump below 2nd oscillation maximum for all values of Δ m 322 , although some fluctuations are seen in the ratio to the unoscillated flux

Fluxes Up to 30 m Off-Axis • Poor fits around the 2nd oscillation maximum for low Δ m 322 region; ability to constrain systematics in this region may be compromised

Fluxes Up to 28 m Off-Axis • Very poor fits around the 2nd oscillation maximum for low Δ m 322 ; limiting to 28 m can cause harm to 2nd oscillation maximum physics

LBNF Proposal • In response, new LBNF design provided exactly 17 m x 35 m of floor space • Note this is 1.6 m *less* in the o ff -axis direction than the conceptual design we have been working with • Goal of this talk is to explore how much space may actually be needed depending on o ff -axis reach and required space opposite the primary o ff - axis direction (including a 2 x 5 m space for LAr utilities)

LAr Configuration 3.5 m A-A 0.7 m A 4.2 m 0.7 m A 6.4 m Extra 50 cm volume required on either side 4.0 m of the active ArgonCube modules 5.0 m 6.4 m Bemerkungen Pos. Anz. Nummer Gegenstand Material A3 Datum Name rohaenni 3/14/2018 Gez. Freig. Gewicht: Ausgabe Blatt Nr. Massstab Assembly_ND 1 1 von Aus- Ä nderung Datum Name Zusammenst. Nr.: Ersetzt durch: Ersatz f ü r: gabe

LAr Detector Parameters • Cryostat walls are 0.7m thick Best Worse Worse • 50 cm of inactive LAr is required on either side of the ArgonCube Efficiency Efficiency Efficiency modules (inside the cryostat) for cryo-coolers, pumps, and instrumentation (previous slide) Veto region Vertex selection Vertex desert • The pictures that follow show a detector that is 8 m wide, rather region than 4 m wide (for illustration purposes), but the conclusions do Hadr. shw. not depend strongly on the detector width y • The FV considered in this study has a 1.5 m of active area on μ x either side of the detector in which event vertices are not allowed • This is to make the e ffi ciency due to hadronic shower containment uniform across the fiducial volume Position 4 Position 2 … Position 3 Position 1 • This value has not yet been optimized, but 1.5 m is almost certainly su ffi cient (may be able to shrink this somewhat) • We are also including a 2 x 5 m platform next to the LAr detector for cryogenics and electronics systems that can move with the Efficiency detector

Layout Diagrams • The following are keynote “engineering drawings” for the ND hall with LAr detector & utilities platform • The numbers are rounded, but the figures should be accurate to ± 1 pixel (15 pixels per meter) • The following modifications to the LBNF proposal are considered in various combinations • Shortening the distance between the beam center & the wall in the shorter o ff -axis direction • Lengthening the distance between the beam center & the wall in the longer o ff -axis direction (to achieve measurements up to 30 m & 33 m o ff -axis)

ND Hall Layout (LBNF Hall Proposal) 42.6 m (15 px/m) Egress Support Space 17 m (15 px/m) Primary Shaft FV FV Ä Ä ü ü Ä Ä ü ü on-axis max o ff -axis beam beam 1 m x 1 m 23.7 m Secondary Shaft o ff -axis 3.7 m 
 7.6 m 
 (12 ft) (25 ft) 35.0 m 
 (115 ft)

ND Hall Layout (LBNF Hall Proposal) w/ LAr Utility Platform 42.6 m (15 px/m) Egress Support Space 17 m (15 px/m) Primary Shaft LAr Utils (2x6.4) FV FV Ä Ä ü ü Ä Ä ü ü on-axis max o ff -axis beam beam 1 m x 1 m 23.7 m Secondary Shaft o ff -axis 3.7 m 
 7.6 m 
 (12 ft) (25 ft) 35.0 m 
 (115 ft)

ND Hall Layout (LBNF Hall Proposal) w/ On-Axis Beam Shift 42.6 m (15 px/m) Egress Support Space 17 m (15 px/m) Primary Shaft LAr Utils (2x6.4) FV FV Ä Ä ü ü Ä Ä ü ü on-axis max o ff -axis beam beam 1 m x 1 m 25.7 m Secondary Shaft o ff -axis 3.7 m 
 5.7 m 
 (12 ft) (18.6 ft) 35.0 m 
 (115 ft)

ND Hall Layout (+4.4m Hall) w/ On-Axis Beam Shift 47 m (15 px/m) Egress Support Space 17 m (15 px/m) Primary Shaft LAr Utils (2x6.4) FV FV Ä Ä ü ü Ä Ä ü ü on-axis max o ff -axis beam beam 1 m x 1 m 30 m Secondary Shaft o ff -axis 5.7 m 
 3.7 m 
 (18.6 ft) (12 ft) 39.4 m 
 (129 ft)

ND Hall Layout (+7.4m Hall) w/ On-Axis Beam Shift 50 m (15 px/m) Egress Support Space Primary Shaft LAr Utils (2x6.4) FV FV Ä Ä ü ü Ä Ä ü ü on-axis max o ff -axis beam beam 1 m x 1 m 33 m Secondary Shaft o ff -axis 3.7 m 
 5.7 m 
 (12 ft) (18.6 ft) 42.4 m 
 (139 ft)

ND Hall Layout (+9.3m Hall) 51.9 m (15 px/m) Egress Support Space Primary Shaft LAr Utils (2x6.4) LAr Utils (2x6.4) FV FV Ä Ä ü ü Ä Ä ü ü on-axis max o ff -axis beam beam 1 m x 1 m 33 m Secondary Shaft o ff -axis 3.7 m 
 7.6 m 
 (12 ft) (25 ft) 44.3 m 
 (145 ft)

Layout Study Summary • The longest option considered was +9.3 m relative to LBNF proposal, and +7.7 m relative to previous LBNF conceptual drawing (i.e. our working assumption over the past year). 
 Notation: (+9.3/+7.7) • Preserves 25 ft space to the left of the beam, and provides measurements up to 33 m o ff -axis • Shortening to (+7.4/+5.8) is the minimum to allow measurements up to 33 m o ff -axis, as long as the short o ff -axis dimension can be shrunk to 5.7 m (18.6 ft) • Further shortening to (+4.4/+2.8) further limits the o ff -axis measurement range to 30 m, which begins limit the ideal o ff -axis range • Although not addressed here, are we confident 17 m along the beam direction will be su ffi cient?