NuMI

NuMI Target
Status, Testing, Support Module

NBI2003
November 7-11, 2003
NuMI Target
Jim Hylen / FNAL
Page 1At NBI’02:• Beam test results of Medium Energy style target(graphite fin clamped by aluminum cooling plates)• Design shown of Low Energy target(graphite soldered to Stainless water pipes)
At NBI’03:• Low Energy target construction complete• Vibration testing of target in progress• Design complete of target carrier (assembly begun)
which allows remotely changing neutrino beam energyOutlook:• Install target in target hall – June 2004• Measure hadron production using (spare) target in MIPP/E907 experiment - Fall 2004
• Commission NuMI with beam – December 2004

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NuMI target collaboration

NBI2003
November 7-11, 2003
NuMI Target
Jim Hylen / FNAL
Page 2IHEP 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
FNAL design team
J.Hylen, K.Anderson
FNAL beam test
J.Morgan, J.Hylen, H.Le, A. Kulik, P. Lucas, G. Koizumi
ANL vibration test
R.Wagner
Energy deposition calculations done with MARS
Target construction done at IHEPNuMI

NuMI target types(Low Energy refers to neutrino spectrum, not beam power)

NBI2003
November 7-11, 2003
NuMI Target
Jim Hylen / FNAL
Page 3Graphite (POCO ZXF-5Q)
is target material

Low Energy Target must fit in horn
this is what we have built
Medium Energy Target
easier, more robust

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Different ν spectra obtained bychanging target and moving 2nd horn

NBI2003
November 7-11, 2003
NuMI Target
Jim Hylen / FNAL
Page 4

L.E. gives MINOS best match
to current SuperK ∆m2NuMI

Reasonable High Energy beam canbe produced by just moving LE target“Semi-beams”
Just moving LE target

NBI2003
November 7-11, 2003
NuMI Target
Jim Hylen / FNAL
Page 5Full Beams
New target, move horn 2

νµ spectra moving off-axis

NuMI

Future off-axis experiment in Minnesota?

2 GeV beam off-axis
M.E.
L.E.

Off-axis experiment probably prefers M.E. configuration

NBI2003
November 7-11, 2003
NuMI Target
Jim Hylen / FNAL
Page 6NuMI

Low Energy Target Construction

Graphite Fin Core
2 int. len.
Water cooling tube
also provides mechanicalsupportAluminum vacuum tube

NBI2003
November 7-11, 2003
NuMI Target
Jim Hylen / FNAL
Page 7NuMI

Target – Internal Monitoring

NBI2003
November 7-11, 2003
NuMI Target
Jim Hylen / FNAL
Page 8Casing of target fin electrically insulated from base.
Wire strung from case to top of module. When moving,can sense if case touches horn by short to “ground”.

Narrow – location checked byscanning beam across edge.
Sense by:(i) charge (delta-rays) knockedout (wire connected totarget) (called Budal)(ii) scattered beam into crosshairs ionization chamber
(BLM)

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Will use Helium instead of vacuumfor high beam power running

NBI2003
November 7-11, 2003
NuMI Target
Jim Hylen / FNAL
Page 9Aluminum vacuum tube is insulated from water cooling to allow Budal monitor to work.
At design beam power, conduction from tube through helium to water pipe is important.
(downstream end still reaches 190 deg C).

Can still use vacuum
for low power beamalignment scans

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NuMI target vibration testing

NBI2003
November 7-11, 2003
NuMI Target
Jim Hylen / FNAL
Page 10Target tip vibration induced by:• Pulsing horn
< 0.01 mm(Target does not touch horn
2.5 mm clearance)• Air flow similar to target hall
~ 0.06 mm• Air flow with target out of horn
~ 0.5 mm(need to redo withouter tube in place)Target in L.E. location in horn
• Water flow(not measured yet)

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Target Temperature (Calculation)- lots of headroom

NuMI beam design parameters:•
0.4 MW beam power•
120 GeV/c proton beam•
4x1013 protons per 8.6 µsec beam spill•
1.87 sec repetition rate•
1 mm RMS circular beam spot size

NBI2003
November 7-11, 2003
NuMI Target
Jim Hylen / FNAL
Page 11

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Target dynamic stresscalculation

NBI2003
November 7-11, 2003
NuMI Target
Jim Hylen / FNAL
Page 12

Safety factor of 3.8
at fin center

Safety factor of 2.2
at curved edge of fin

Note fin is in 2 cm segments
to prevent stress buildup

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Radiation Damageis still the big uncertainty

NBI2003
November 7-11, 2003
NuMI Target
Jim Hylen / FNAL
Page 13

Most radiation damage info isfrom reactor neutrons
In this example, graphite selfdestructs at ~ 2x1020 n/mm2
Highest radiation density in
NuMI target is proton spotnear entrance~ 0.5x1020 p/mm2 / year
NuMI target test accumulated
0.023x1020 p/mm2
with no visible damage
Target longevity uncertain– will gain experience in 2005
Radiation Damage and Life-time Evaluation of RBMK Graphite Stack, XA9642904,
P.A.Platonov, O.K.Chugunov, V.N.Manevsky, V.I.Karpukhin, Russian Research Center Kurchatov InstituteNuMIBaffle

NBI2003
November 7-11, 2003
NuMI Target
Jim Hylen / FNAL
Page 14Protects beamline elements (e.g. target water lines) from mis-steered proton beamthat could do damage in a single pulse
Graphite encapsulated in aluminum tube
150 cm long, 6 cm diamter
11 mm diameter hole for beam
Air-cooling boosted by pin radiators
Scraping of a few percent of beam here
would affect neutrino spectrum
Detect scraping by temperature riseNuMI

Target station in pictures

Target withmotion system

NBI2003
November 7-11, 2003
NuMI Target
Jim Hylen / FNAL
Page 15

1 of 3Supportmodules(10% of )ShieldingBlocks
1 of 2 focusing horns

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Target and Horn hang fromsupport/shielding modules

Target/Baffle
ModuleHorn 1 Module

BaffleCarrier

Water tankTargetHorn 1

NBI2003
November 7-11, 2003
NuMI Target
Jim Hylen / FNAL
Page 16

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Target / Baffle can be remotely moved
2.5 m along beam direction,
20 cm vertically, +/- 8mm horzontally
Shielding /Support
ModuleDrive motors

NBI2003
November 7-11, 2003
NuMI Target
Jim Hylen / FNAL
Page 17

Vertical motion gets target outof way for beam scan ofhorn cross hairs

BaffleTargetT/B Carrier

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Target/Baffle Carrier

NBI2003
November 7-11, 2003
NuMI Target
Jim Hylen / FNAL
Page 18

Support shafts move whole carrier for transverse motion
but motion along beam uses ball screw below module
to push/pull cradle
TargetRollers

Dirt on screw drive test – no problem

BaffleWater lines compress
like springNuMI

NuMI Target
Summary

NBI2003
November 7-11, 2003
NuMI Target
Jim Hylen / FNAL
Page 19At NBI’02:• Beam test results of Medium Energy style target(graphite fin clamped by aluminum cooling plates)• Design shown of Low Energy target(graphite soldered to Stainless water pipes)
At NBI’03:• Low Energy target construction complete• Vibration testing of target in progress• Design complete of target carrier (assembly begun)
which allows remotely changing neutrino beam energy
Outlook:• Install target in target hall – June 2004
• Measure hadron production using (spare) target in MIPP/E907 experiment - Fall 2004
• Commission NuMI with beam – December 2004