1. July 2005A.Fabich, CERN AB-ATB1 MERIT (ntof11) experiment: Diagnostics A.Fabich CERN AB-ATB http://cern.ch/proj-hiptarget July 2005

2. A.Fabich, CERN AB-ATB 2 Installation on beam line Proof-of-principle test of a liquid mercury jet target for multi-MW proton beams Beam attenuator Mercury loop Solenoid proton beam Target chamber

3. July 2005 A.Fabich, CERN AB-ATB 3 Target chamber Cut view side view

4. July 2005 A.Fabich, CERN AB-ATB 4 Primary Containment Cross Section Hg Supply Hg Jet Primary Containment Sight Glass Cover Reflector Sight Glass Optics Secondary Containment OD=6.18" (157mm) Magnet Bore ID = 6.38" (162mm) ~9 cm

5. July 2005 A.Fabich, CERN AB-ATB 5 Optical Diagnostics Shadow photography to visually observe mercury jet behaviour tight environment high radiation area high magnetic field: 15 Tesla pulsed non-serviceable area passive components optics only (no active electronics) back illuminated with a single fiber laser - pulsed laser X transmit image through flexible fiber bundle

6. July 2005 A.Fabich, CERN AB-ATB 6 Optical Diagnostics test target retroreflected illumination Spherical mirror laser illumination image collection Works OK in this tight environment cm scale

7. July 2005 A.Fabich, CERN AB-ATB 7 Radiation hardness Almost all parts sufficiently radiation hard BUT the fiber: 0% transmission after exposure to MERIT equivalent Search for fiber replacement is ongoing, but alternatives to present scheme have to be investigated …

8. July 2005 A.Fabich, CERN AB-ATB 8 “Pixel detector” What kind of pixel detectors are there? ATLAS, CMS enviroment: radiation, B-field, … Can we adapt such a system for our needs?

9. July 2005 A.Fabich, CERN AB-ATB 9 Operation Scenario Single pulse experiment About 150 extractions (integrated intensity < 3 10 15 protons) One extraction of up to 3*10 13 protons @ 24 GeV every ~30 minutes Proton beam properties change from pulse to pulse Solenoid temperature Proton intensity B-field and repeat

10. July 2005 A.Fabich, CERN AB-ATB 10 High Field Pulsed Solenoid collecting device for mesons 80 K Operation to optimize for costs Not superconducting! 15 T with 4.5 MW Pulsed Power 15 cm warm bore (L=1m) 4.5 ton Peter Titus, MIT power cycle 15 seconds Cooling cycle of solenoid limits to a minimum repetition time of 30 minutes between two pulses!

11. July 2005 A.Fabich, CERN AB-ATB 11 Radiation environment Simulated neutron flux at r = 0.6 m Radially: 10 -3 n/cm 2 /p.o.t. Forward: 1.2 x 10 -3 n/cm 2 /p.o.t. Backwards: 1.6 x 10 -3 n/cm 2 /p.o.t. Diagnostics are located at r = 0.03 cm → 400x A test in ISOLDE (1.4 GeV) with a total of 4*10 15 p.o.t. resulted in 3 kGy. At MERIT we expect more like 50-100 kGy.

12. July 2005 A.Fabich, CERN AB-ATB 12 Diagnostic specifications Area of “view”: 4 x 8 cm x 8 cm = 250 cm 2 Spatial resolution: ~ 0.2 mm Shutter time: ~1 micro-second Frame rate: 10 kHz to 1 MHz Record time: up to 1 second Radiation hard Exposable to 15-Tesla field, < 50 T/m