1. Target and Horn status report
Simone Gilardoni - PS Division Helge Ravn – EP Division For the Target and Horn Working Group

2. Schedule of the CERN Horn and Hg-jet R&D work in 2001
January Off-line tests of the Hg pump and jet
January Delivery and test of the endoscope and camera
February Commissioning of a Hg-jet in a 1.5 T CERN magnet
February Test the Hg-jet in a 13T magnet at Grenoble
February Planning a Hg-jet test in a 20 T Grenoble magnet
February Final design of the chamber for the Hg-trough test
April Successful tests of Hg-trough and –jet at Brookhaven
June Design and construction of a horn prototype
July Design and construction of a prototype horn power supply
September Hg-trough installation and feasibility test at ISOLDE
September Test the Hg-jet in a 20 T Grenoble magnet
October Redesign the Hg-jet chamber for the 20 T magnet
October Find specialists in hydrodynamics and heat transfer from the direct water- cooled granular metal target
December Finish and start testing the horn power supply
Work done Work in progress

3. Ongoing effort to integrate target and horn
Where we are ….
Ongoing effort to integrate target and horn
Target experiment
trough test at ISOLDE
New horn design
a short historical introduction
Horn test
Plans for future

4. Target+Horn station CERN work scenario

5. Isolde Mercury test setup
p beam
frontend
Hg container
mirror
camera

6. Plans of the CERN Hg-jet R&D work in 2002
January Test the Hg-jet in a 20 T Grenoble magnet.
January Start designing the spent beam absorber for the super- beam target version.
February Make a plan for which parameters of solid and liquid metal targets should be experimentally determined, what equipment is needed for their measurement.
April Systematic Hg-trough tests at ISOLDE.
April Modify existing hydrodynamic codes to which the experimental results should be compared.
April Start planning the in-beam tests of the Hg-jet in the ISOLDE target area.
March Design the vacuum vessels and support including Hg circulation and on-line distillation needed for the in-beam Hg-jet.
September Building and off-line testing of the in-beam Hg-jet.
October Request on-line tests of the Hg jet in the ISOLDE proton beam.

7. From results of target experiment ...
Inner Hg pipe
Shock due to Hg disruption
Thickness and material
Hg hydrodynamics
Speed of the Hg drops
Effective target length
Hg damping surface
best place
thickness

8. Old horn design Current: 300 kA Inner radius: 1.6 cm
Outer radius: 100 cm Technical Limits
High inductance Reduce high B field volume
Space for target
Hg - inner conductor insulation
LARGER INNER RADIUS

9. New “double” horn design
Increase of B at large radius
600 kA
300 kA
Old horn neck R = 1.6 cm
New horn neck R = 4 cm B field is 2.5 times smaller !
First decay channel solenoid

10. Horn to maximise the m flux for the phase rotation
Beam dynamics study
Horn to maximise the m flux for the phase rotation
Muons: MeV < EKinetic < 300 MeV
With new design flux losses of %
Pions have to be injected in the fringe field of the first decay channel solenoid
Constraints: max R = 30 cm, max P  80 MeV/c (Bsol=1.8 T)
Matching between horn and solenoid under study
Open question: relative position between horn and solenoid
Overlapping the fields?
One solution found: better to inject with small spot size but with a non parallel beam

11. From results of beam dynamics and Monte Carlo study ...
Inner Hg pipe
Max thickness allowed for pion absorption
First decay channel solenoid
Fringe field effect on focusing
Energy deposition in the first coil
Beam composition
pronton and neutrons flux
Hg damping surface
Max thickness allowed for pion absorption

12. Inner horn technical drawing
Water spray
Water channel

13. Where is the life time limit ?
Life time CNGS horn: ~ 2*107 pulses years at 95% C.L.
Life time NuMI horn: ~ 107 pulses year
Life time Nufact horn: ~ 2*108 pulses weeks at 95% C.L.
Who is the killer?
fatigue limit
stress due to electro-magnetic forces
thermal stresses
joule losses
particle energy deposition (still to be evaluated)

14. Plans for ongoing horn program
Power supply for Test One in construction in BA7
Ready for first test in December
First “inner” horn 1:1 prototype in construction
Ready for test in February
Test One: 30 kA and 1 Hz
First mechanical and thermal stresses measurements
Test of numerical results for vibration (work in progress)
Test of cooling system
Based on existing power supply
Test Two: 300 kA and 1 Hz
Depending on power supply
Last test: 300 kA and 50 Hz

15. Discussion of Design Methodology Cooling
To print from original !
Nozzle Heat Transfer Coefficient Measurement

16. A lot of work for results in a near future is going on Hot topics:
Conclusion
A lot of work for results in a near future is going on
Hot topics:
Results from ISOLDE experiment
Results from horn test
Target and horn study has to proceed in parallel:
material budget
horn shape
Thanks to all the collaborators also from outside CERN

17. Remark on pbar-horn
Current : 400 kA
Protons: GeV *1013 p/pulse sx=1 mm rms