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MINOS/NuMI projects

●Introduction to kingdom MINOS/NuMI ●Physics goals of MINOS ●Kingdom built

●NuMI beamline ●MINOS detectors

●Running the kingdom - data taking● Atmospheric● Beam

● Summary

Hai ZhengHai ZhengCaltechCaltechMINOSMINOS

King Minos holding the sceptre that Zeus himself gave him

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Near Detector980 Tons measure the beam energy spectrumFermilab, IL

Far Detector5.4 kTons measure the oscillationSoudan, MN

Introduction MINOS is an accelerator-based Long-Baseline

neutrino experiment to study oscillationwith

high statistics ’s are generated at Fermilab from 120 GeV protons and delivered by the NuMI beamline

Both detectors have magnetic fields:

first large underground detectors to identify - and + separately

Detector 2

Detector 1 735 km

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MINOS Physics goals

m223

disappearance :– Confirm oscillations

– Precise Measurement of sin2(223) & m223 :

● Poscillationsin2(223)sin2(1.27m223 L /E)

● Goal: 1 precision 3-5%

Search fore appearance:

• Might be able to observe e appearance

Atmospheric measurements and capable of first direct observation of separated atmospheric ν and ν oscillations

P(esin2(213)sin2(23)sin2(1.27m2 L/E)

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MINOS sensitivity for m2 and sin22

• location & depth of the signal yield m2 & sin22measurements• be able to rule out non-oscillation models• precision improves with additional protons

For m2 = 0.0025eV2, sin22 = 1.0

Oscillation measurement: Compare the observed energy spectrum at the far detector to the expected un-oscillated spectrum calculated from the near detector measurement

Left: the ratios of oscillated to un-oscillated spectrum

signal

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MINOS Sensitivity to e Appearance

For m2 = 0.0025 eV2, sin2 213= 0.067

Assuming 25 x 1020 protons on target

Background dominated by Neutral current interactions

(+ some intrinsic beame’s)

Energy Spectrum

m2 = 0.0025 eV2

detection of e at m2atm

evidence for non-zero 13

Can improve 90% CLby a factor of ~2 with higher proton intensity

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NuMI – MINOSNuMI – MINOS @ Fermilab @ Fermilab

Tevatron

MainInjector

Booster

TargetEnclosure

DecayEnclosure

MINOSNear

Detector

To Soudan M

ine

NuMI BeamlineNuMI BeamlineTo transport protons to the To transport protons to the target & generate the target & generate the beam beam Designed for up to 4 x 10Designed for up to 4 x 101313 protons/pulseprotons/pulse

Earlier commissioning:Earlier commissioning:●Delivered low proton intensity on the Delivered low proton intensity on the target with low repetition ratetarget with low repetition rate

February 18-March 23, 2005:February 18-March 23, 2005:•Varied Varied energy spectra by moving the energy spectra by moving the targettarget•MI was operating w/ high proton MI was operating w/ high proton intensityintensity

•reached up to 2.5reached up to 2.5 x 10x 101313 ppp ppp•Repetition rate was increased to Repetition rate was increased to nominal rate of 0.5 Hznominal rate of 0.5 Hz

Main Injector (MI) Main Injector (MI) goal for this yeargoal for this yearaccelerate 2.5 x 10accelerate 2.5 x 101313 protons protons every 2 seconds to 120 GeV every 2 seconds to 120 GeV ~8 ~8 sec spill,sec spill, 0.25MW 0.25MW

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NuMI Beamline Layout & components

Components

Layout• Aimed downwards at 58 mrad toward the Soudan mine

• Protons hit segmented graphite target & charged hadron beam is focused with two magnetic horns

• 675m long steel vacuum decay pipe

• Hadron monitor and hadron absorber downstream of decay pipe

• 200m rock upstream of Near Detector for muon absorption & muon monitors

207 m

ProtonsProtons

π, K

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Horn 2

• 6.4 x 15 mm2

• ~1 m long: 2 interaction lengths

Graphite target w/ water cooling tube

target vessel (vacuum) with beryllium window

Target and Horns

Back face of horn 2Assembled horn 1

• Parabolic shape of inner horns gives focusing• 200 kA peak current• 3 Tesla peak field• 1.87 sec repetition rate(designed)

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Target Water Leak• Water-cooled graphite fins sit inside a vacuum chamber

• Target was filled with water in March, investigated• Leak self-repaired, target back in, operations resumed.

–Leak reappeared, now back pressuring helium–2nd target will be ready in Aug.–Building another spare target –Interesting facts learned:

• Beam scans across the target confirm extra material (proton radiography)

Attenuation through water?

Water Filling Target Can Water Being Pumped

from Target Can

Multiple scattering

through H2Obaffle baffletarget

baffle baffle

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• Can change the energy spectrum by moving the target (shown in plots), or by moving horn 2, but needs more work

NuMI eam Running

Target is inside horn 1 (LE)2.5 x 1020 protons/year produces ~1600 CC events in FD assuming no-oscillation

Energy spectra for different target positions

Data acquisition was stopped because of water leak in the target

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60-plane ‘micro - MINOS’ -- has taken data at T7 & T11 test beam lines at CERN during 2001, 2002, 2003

MC expectation

Calibration Detector

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Far Detector

8m octagonal tracking Calorimeter486 planes (5.4 kTon total)2 super modules(SM) : 15 m long eachToroidal B-field: 1.3 T at r = 2m Veto shield for cosmic’s Completed in July 2003 Recording cosmic ray muons since 2002

Plane with scintillators installedCompleted Far

Detector

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Near Detector at Fermilab

Completed Near Detector

Partial plane Full plane

Same basic design as the far detector but smaller

• 282 single steel planes• 980 Tons

Combination of partially & fully instrumented planes

● Calorimeter (120 planes) is partially instrumented except for 1/5 of planes with full coverage

● Spectrometer (162 planes) has only every 5th plane instrumented

Plane assembly was completed in August 2004

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MINOS Running• To ensure smooth running of the long baseline neutrino experiment,

we need good coordination and monitoring between near and far sites

• Experts on-call• Fermilab main control room – physicist shifters• Soudan control room – now mainly mine crew, not 24/7

• Collaboration with Fermilab accelerator division on different projects for better beam quality and high intensity beam

• NuMI beam monitoring and instruments• MI/Booster upgrade and improvements, such as:

• damper system to reduce oscillation amplitude• cogging to synchronize Booster extraction with MI with

multi-batch operation• and many more ...

• Proton intensity, such as barrier RF stacking and slip stacking• Overlapping collaborators with experiments such as MIPP,

MINERA, with broader scope of neutrino physics in mind

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Atmospheric •Since completion in August 2003 the Far

Det has been taking atmospheric neutrino data.

•Beam switched on 1st March 2005 at which point the Far Detector had collected 420 days of physics quality data, excellent for a detector still in commissioning stage.

•Total of 6.18 kton-years of data suitable for atmospheric neutrino studies, c.f. Soudan 2's 7.36 kton-years

•Will still take atmospheric neutrino data during beam running.

•Publication coming soon, stay tuned!

MINOS PRELIMINARY

DATA

V vs Z

ADC vs Z

Time vs Z(2.4 ns)

U vs Z

stopping

with

veto hits

Example EventsFully Contained Partially Contained

Downward Going

ν induced μPartially ContainedUpward Going

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Accumulating beam data at both detectors !!!

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Incoming Direction for Near Detector Neutrinos

• Zenith and azimuth show point of origin of the neutrinos within spill time

• Beam points downward 3.3 degrees, expect peak at cosθ = 0.06

• Beam also points west of north, expect peak at 156 degrees

• Neutrinos definitely coming from the beam! S

EW180

90270θ

Near Det.

Thousands of 's already!

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2.51012protons/1.6s spill

Separation of two categories of interactions:

• Interaction inside of the near detector: Fully contained event

• from interaction in the rocks surround the near detector: Rock this one goes through the whole detector

Interactions of the beam in Near Detector

Beam direction

MINOS preliminaryBack view

v

u

u view

v view

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First beam event at Far Detector: Rock

Event seen in both SuperModule1 & SuperModule2Charge identification from curvature : -Detected momentum ~12 GeV from curvature & the # of planes the track passed

Entrance point

x

y

B

Beam direction

MINOS preliminary

u view

v view

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First Fully Contained Event in Far Detector

Beam direction

Showering event(Neutral Current candidate?)

MINOS preliminary

discovered by our Greek collaborator at the end of March

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More Far Detector Events

Beam direction

Charged current quasi-elastic scattering candidate n p?

MINOS preliminary

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More Far Detector Events

MINOS preliminary

Freshly produced in May

Another Charged Current

Candidate

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More Far Detector Events

MINOS preliminary

Freshly produced in May, from the same run

Showering Event (

e Candidate?)

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Summary

●NuMI beamline is completed and commissioned●2.5x1013 protons/spill & 0.5 Hz repetition rate have been achieved separately

●Water leak in target investigated and under control●MINOS detectors are completed & operating

●acquiring atmospheric ’s with over 90% live time, first publication coming out soon!

●beam data-taking at both detectors•precise measurement of m2 and sin22•search for non-zero by detectinge appearance

●Minoans have been working hard and eagerly await the final judgment

`Thus I descended from the first circle down into the second, which girdles less space, and so much more woe that it goads to wailing. There abides Minos horribly, and snarls; he examines the sins at the entrance; he judges, and he sends according as he entwines himself.'

Dante Alighieri - Divina Commedia

Gustave Dore