Targets nFact03

1
Targets _at_ nFact03

• Paul Drumm
• Rutherford Appleton Laboratory

2
Programme

• Plenary Talks
• Neutrino factory RD Overviews
• Haseroth in Europe
• Mori in Japan (no info on targets)
• Zisman in US
• Targetry experimental plans and results
• Kirk McDonald

3
WG3
Neutrino Scattering and Muon Physics

• Target RD Session (joint with WG2)
• Targetry plans in Europe
• Roger Bennett
• US target program
• Harold Kirk/Kirk McDonald
• MECO target Popp
• PRISM target Koji Yoshimura

4
EU Target RD

• or the art to talk for half an hour about
  nothing
• but actually, theres quite a lot to show
• Helmut Haseroth (Plenary)
• Roger Bennett (WG3)

5
Assets
Target Studies
6
ISIS

• Staged ISIS upgrades to 1 4 MW
• Potential NF test facility _at_1MW,
• 3 GeV, 50Hz
• 8 GeV,16.67 Hz
• Bunch compression target tests

7

• The Liquid Metal (Mercury) Jet
• The jet is constantly being reformed for every
  pulse. The jet becomes heated by the beam and
  disperses to hit the walls
• No Problems with
• Radiation Damage
• Shock Damage
• Power dissipation
• Possible Problems with
• Jet formation
• Interaction with the magnetic field
• Interaction of the mercury with other equipment
• Tests to date indicate that the jet is viable

8
Hg-jet p-converter target with a pion focusing
horn
9
Targetry
Many difficulties enormous power density ?
lifetime problems pion capture
Replace target between bunches Liquid mercury
jet or rotating solid target
Stationary target
Proposed rotating tantalum target ring
RAL
Sievers
10

• A Water Cooled Cu-Ni Rotating Band Target (BNL
  and FNAL, Bruce King)
• A Radiation Cooled Rotating Toroid, (RAL)
• TOROID OPERATES AT 2000-2500 K
• RADIATION COOLED
• ROTATES IN A VACUUM
• VACUUM CHAMBER WALLS WATER COOLED
• NO WINDOWS
• SHOCK? Pbar target OK. Tests using electron beam
  simulation indicate no problem.

11

• Advantages of Solid Target
• No windows
• Cooling in the walls
• Simple concept
• Disadvantages
• Large rotating toroid or individual targets
• Problems if toroid breaks
• Thermal shock - toroid breaks
• Very radioactive

12
Granular target
Dt vs.D Increased rep. rate Larger
beam Stress from DT ltlt Elastic Limit
see Bruno Autin
13
E Beam Tests
Tests by RAL with electron beams show that
tantalum foils can withstand at least 200,000
pulses and have lasted for 1,000,000.
14
Granular Target
15
Funneling step by step

• Advantages for Horn Targets
• 25 average power
• Still have shock effects / power microstructure
  dependent

16
Contained liquid metal
17
Zisman
18
pulsed solenoid
15T
AGS J-PARC ?
19
Carbon Sublimation

• Materials with Low CTE
• suffer less thermal shock
• Carbon limited by sublimation
• suppressed by helium atm.
• limited by radiation damage
• other materials?

Kirk McDonald
20
Z2
21
Bennett

• Review of work in Europe
• Jets in beams and fields
• CERN/BNL, Grenoble
• still to do full speed tests in a B field
• Solid targets radiation cooled, Granular
• Contained Liquid Metals
• Future Plans
• EU network
• Bids to UK funding agencies (15 M)
• High power tests at ISOLDE or RAL

22
Kirk

• US high average power SNS high peak
  power NLC
• shared Interest
• Carbon target studies at AGS (1MW)
• Alternative Iron Alloys
• low CTE
• Irradiation tests
• evidence of damage related effects

23
Meco (J.Popp)

• Search for m to e conversion in a nuclear field
• Proposal to BNL/AGS
• 6 uA, 7.5 GeV
• 16cm long, 6-8mm diam. Target
• Considered radiation
• water cooling

24
Thermal Tests
Getting a lot of experience - not a trivial
problem
25
Prism Studies

• 40kW water cooled target
• Conducting Target ideas

Confine pions inside the target with toroidal
field - B. Autin, _at_Nufact01 Advantage over
Solenoid Low emittance beam Linear transport
element No SC solenoid channel Cheaper! Cooling
condition better?
26
Target Candidates

• Mercury is good candidate
• Minimum Power
• Easy to cooling
• Higher pion yield
• Technical Issues
• How to cut off electrical circuit?
• Stress due to pinch effect
• Container
• Shockwave
• Cavitation
• Thicker wall can be used!
• No reabsorption
• Window

Mercury Circuit Test Loop built
B. Autin et al.