S.Kopp: NuFact ’02, Imperial College, London 1 The NuMI Neutrino Beam I. Status of 0.4MW Beam II. Potential for 1.6MW II. What’s it Good For? Sacha E. Kopp, University of Texas – Austin for the NuMI/MINOS Collaboration

S.Kopp: NuFact ’02, Imperial College, London 2 NuMI has 400kW primary proton beam 120 GeV 8.67  sec spill 1.9 sec rep rate MINOS (Fermilab to Minnesota) L = 730 km Beam Axis 3.32 o into the ground at FNAL, exits at Canadian border. 2 o off-axis in southern Canada or northern Wisconsin (L = 530 – 950 km) (12 km)

S.Kopp: NuFact ’02, Imperial College, London 3 NuMI Tunnel 105 m Soil Dolomite rock Decay volume 2m Ø, 675 m long (10 GeV  ) Near Detector on beam axis Also access passageway available for near off-axis detector Beamline passes through 3 acquifers

S.Kopp: NuFact ’02, Imperial College, London 4 NuMI Extracted Proton Beam Passes through acquifers »10 -4 losses throughout beamline (magnets activated to 200mrem/hr). »10 -6 losses in ‘transition’ soil-rock region (groundwater activation). Two major bends »150 mrad bend downward from Main Injector »100 mrad bend upward toward Soudan Want to be even more conservative in design »First operation of Main Injector in multi-batch mode »Emittance growth with intensity  h,  v ~ 25  mm-mrad measured in MI (design for 40  )  l, ~ eV-sec measured in MI (design for 1 eV-sec) (  p/p ~ 5  ) »Potential routes to improve proton intensity include batch ‘stacking’ Plan for 2-4  larger emittances.

S.Kopp: NuFact ’02, Imperial College, London 5 Improved Extraction Channel Added $0.5M in focusing in 40m drift region through soil-rock interface. Old DesignNew Design figures courtesy S.Childress

S.Kopp: NuFact ’02, Imperial College, London 6 Target Hall Beamline Component Positioning Modules Two Types of Magnetic Focusing Horns Pion Production Target (plus readout of target, vacuum pump) Baffle to protect horn from beam accidents Target Hall Radiation Shielding Radioactivated component work cell Alternate Horn Positions (eg: for off-axis exp’t)

S.Kopp: NuFact ’02, Imperial College, London 7 NuMI Target Hall Horn+Module in transit Stripline Concrete Cover “Carriage” - Module Support Beams Horn Shielding Module Horn Steel Shielding Air Cooling Passage Concrete Shielding Temporary Stackup of removed shielding Steel from module middle Concrete from over horn Beam passageway (chase) is 1.2 m wide x 1.3 high, forced-air-cooled Shielding protects groundwater below personnel above Air volume sealed, recirculated

S.Kopp: NuFact ’02, Imperial College, London 8 NuMI Production Target FNAL design team J.Hylen, K.Anderson FNAL beam test J.Morgan, H.Le, Alex Kulik, P. Lucas, G. Koizumi IHEP Protvino design team: V.Garkusha, V.Zarucheisky F.Novoskoltsev, S.Filippov, A.Ryabov, P.Galkin, V.Gres, V.Gurov, V.Lapygin, A.Shalunov, A.Abramov, N.Galyaev, A.Kharlamov, E.Lomakin, V.Zapolsky Target read-out Budal mode

S.Kopp: NuFact ’02, Imperial College, London 9 Prototype Target Test Teeth show no damage after 7x10 17 protons 3x10 5 pulses 2x10 18 protons/mm 2 (~ 1 NuMI week ) Max. stress pulses: 1x10 13 /pulse 0.2 mm RMS spot NuMI Design: 4x10 13 /pulse 0.9 mm spot, 23MPa stress (cf 100MPa limit) If go to 1.6MW beam, require spot size  2.0mm -Maintains target temperature -Maintains target stress -Long-term radiation damage?

S.Kopp: NuFact ’02, Imperial College, London 10 Target and Horn Modules Water tank Stripline Remote Stripline Clamp Baffle Target Target/Baffle Module Horn 1 Module Horn 1 25 cm wide, 2 m deep Steel endwalls with positioning, water, electric feedthroughs Motor drives for transverse and vertical motion of carrier relative to module Carrier Target moves 2.5 m along beam figure courtesy E.Villegas

S.Kopp: NuFact ’02, Imperial College, London 11 Stripline and Remote Connections Stripline shielding block stays with module Remote clamp allows horn disconnection from module (for horn replacement)

S.Kopp: NuFact ’02, Imperial College, London 12 Target/Horn Module Carriages Carriages: Cross-beams that modules rest on 130 o C 15 o C

S.Kopp: NuFact ’02, Imperial College, London 13 Horn 1 Prototype

S.Kopp: NuFact ’02, Imperial College, London 14 Design & Procurement Status Horn 2 Outer conductor: is currently being machined Inner conductor: Welding parameters being developed on test pieces Have done 1 st two welds on real horn Finish assembly horn 2 ~ end of year

S.Kopp: NuFact ’02, Imperial College, London 15 Horn Field Measurement Main horn field between conductors Field between conductors:  1/r as expected very symmetrical agrees within meas. error with current

S.Kopp: NuFact ’02, Imperial College, London 16 Horn Field Measurement in ‘field-free’ region through center of horn Error or fringe field in “field-free” region down center of horn is so small that no correction should need to be put into the Monte Carlo. Measurement with probe moving along horn axis 2% F/N criterion on flux in M.E. beam (approximately scaled to 0.85 ms test pulse from 2.6 ms operational pulse)

S.Kopp: NuFact ’02, Imperial College, London 17 NuMI Horn 1 Vibration Measurement on Horn Bell Endcap 6  m 55  m (ANSYS gives 71  m) 1.17 kHz (ANSYS 1.19 kHz) DATA Linear Model DATA Linear Model 2 sec0.03 sec NB: proton intensity upgrade is non-trivial if it requires faster rep-rate. figures courtesy J. Hylen

S.Kopp: NuFact ’02, Imperial College, London 18 TBM in Target Hall (May 2001) TBM - front TBM - back

S.Kopp: NuFact ’02, Imperial College, London 19 NuMI Decay Tunnel - July 2001

S.Kopp: NuFact ’02, Imperial College, London 20 Decay Pipe 2m Ø steel cans, 1 cm wall. Reinforced by 4” 20 ft. Decay volume evacuated to ~ Torr Helium-filling is a backup Complete decay pipe now in place, welded, inspected. Dual entrance window »Inner 1m Ø = 1.5mm Al »Outer 2m Ø = 1.0 cm Fe »Should readily handle increase in beam power (currently designed for beam accident)

S.Kopp: NuFact ’02, Imperial College, London 21 Sample Pipe / Shielding View concrete radiation shielding, density 2.1 g/cm 3 Decay pipe Decay region power deposition »63 kW in 1 cm thick steel decay pipe »52 kW in shielding concrete »Peak deposition in the steel is ~360 W/m »Drops to 20 W/m (at ~610 m) Heat removed by water-cooling »12 plastic-coated copper lines »Final temperature ~ 50 o C May be expensive to upgrade for  4 beam intensity. Target hall to absorber secondary access Relative centers vary along length

S.Kopp: NuFact ’02, Imperial College, London 22 Beam Absorber Egress path Absorber core »8 aluminum plates 30.5 x x cm 3 »dual water-cooling paths »8 kW peak power in one module (normal beam conditions) »followed by 10 plates of steel, each 23.2 cm thick. Total power into Absorber: 60 kW (400 kW beam power if accident) Water-cooled Aluminum easily can accommodate increased beam power from proton upgrad Steel is more problematic – require adding water cooling? Concret e blocks Absorber coreSteel blocks

S.Kopp: NuFact ’02, Imperial College, London 23 Summary of NuMI Upgradeability table courtesy N. Grossman

S.Kopp: NuFact ’02, Imperial College, London 24 Off-Axis case for Existing NuMI Plots assume current neutrino target, horns. Variable energy beam can help move peaks dynamically Antineutrino running takes factor 3 hit in rate NuMI ME Beam NuMI LE Beam figures courtesy M.Messier

S.Kopp: NuFact ’02, Imperial College, London 25 Instrinsic e in Off-axis Beam NuMI decay tube is quite long (675m) Good news: bckgd uncertainty lower in off-axis case. Back-fill last ~200m (water?) to reduce  decays for new exp’t? All e backgrounds From K decays figures courtesy M.Messier, R.Zwaska

S.Kopp: NuFact ’02, Imperial College, London 26 e Backgrounds Summary Plot assumes |U e3 | 2 =0.01,  m 2 =3.0  eV 2. NC is all interactions before any identification cuts. Detector design requires >10  reduction in NC events? For rest of discussion, assume NC reduced to level of beam e. figure courtesy M.Messier

S.Kopp: NuFact ’02, Imperial College, London 27 Comparison of Exp’ts Assume  m 2 = 3.0  eV 2, sin 2  13 =0.1, For NuMI, assume a 20kt detector, 85% fid.vol, analysis of low-Z calorimeter NuMI can make up for lower proton power, longer baseline because of higher neutrino, pion, cross sections. NuMI-MINOS, 2 8E20 POT NuMI Off-Axis, 4E20 POT/yr 712 km baseline JHF Phase I, 0.77MW 295 km baseline

S.Kopp: NuFact ’02, Imperial College, London 28 Interpretation of PhaseI Results Interpretation of   e observation Observation would be strengthened by antineutrino running.  Sign(  m 2 ) 

S.Kopp: NuFact ’02, Imperial College, London 29 Antineutrino Running Can we disentangle mass heirarchy and CP violation?

S.Kopp: NuFact ’02, Imperial College, London 30 Compare Baselines 950km 712 km 295 km sin 2  13 =0.02 sin 2  13 =0.05  m 2 >0  m 2 <0  m 2 >0  m 2 <0

S.Kopp: NuFact ’02, Imperial College, London 31 More Protons for NuMI Original baseline 4E13 protons/spill, 4E20/yr. Present performance of Booster is E12protons/batch (5 batches per MI extraction) Possible paths to improvement »Get all 6 Booster batches (post-collider) »Multi-filling of MI (‘stacking’) »Reduce MI acceleration time (requires new RF) Potential proton source upgrades -- $200M+ »16 GeV ‘proton driver’ »8 GeV proton LINAC (R&D for Linear Collider)

S.Kopp: NuFact ’02, Imperial College, London 32 Summary NuMI is substantial investment in US HEP program Design is flexible to permit variations, upgrades NuMI off-axis exp’t has complementary capabilities to JHF Real attack of CP violation requires substantial extensions to existing plans -- JHF-II and NuMI-II »4MW proton beam for JHF, 1.6MW for NuMI »HyperKamiokande, NuMI would have …? Lots more extensive documentation: »Letter of Intent to Build an Off-Axis Detector for NuMI, www-numi.fnal.gov/new_initiatives/new_initiatives.html »“The Proton Driver Design Study”, FERMILAB-TM-2136 » G.W.Foster, W. Chou, E. Malamud, FERMILAB-TM2169. »“Physics at FNAL with Stronger Proton Sources”, FERMILAB-FN-720