# Presentation: 636067

## High-Power Targetry

- Fermilab
- December 20, 2005

***Fermilab, Accelerator Physics***
***Energy Deposition Group***

_**Fermilab Muon R&D**_

- Nikolai Mokhov

## OUTLINE

- Neutrino Factory Target Concepts
- Targetry Issues
- Simulations, Benchmarking, Optimizations
- MERIT Experiment at CERN
- Target Test Facility at FNAL

## NEUTRINO FACTORY TARGET CONCEPTS

- 3. Rotating inconel band:
- performance in between (1) and (2)

- 1. Baseline: Tilted mercury jet in 20-T solenoid,
- highest yield, Megawatt beams

- 2. Graphite rod: lowest yield,
- bad for low-energy beams,
- good for < 0.8-1 MW

**Aspect ratio v:h = 1:20**

- 4. Levitating tantalum  Hula-Hoop (RAL)

## TARGETRY ISSUES

**To design high-efficiency target system and achieve its best performance, one needs to address the following issues:**
-  Production and collection of maximum numbers of /.
-  Suppression of background particles down the beamline.
-  Target and beam window operational survivability and lifetime: compatibility, fatigue, stress limits, erosion, remote handling and radiation damage.
-  Protection of a focusing system including provision of superconducting coil quench stability.
-  Heat loads, radiation damage and activation of components.
-  Spent beam handling, and shielding issues from prompt radiation to ground-water activation.

## SIMULATION CODE REQS

- Reliable description of x-sections and particle yields from a fraction of eV to many TeV for hadron and heavy-ion projectiles (event generators).
- Leading particles (elastic, diffractive and inelastic).
- 0 – production (EMS) and K0 – production (e).
- Annihilation, stopped hadrons and muons.
- Nuclide inventory, residual dose, DPA, hydrogen and helium production.
- Multiple Coulomb scattering (not a simple Gaussian or Molier).
- Hadron, muon and heavy- ion electromagnetic processes with knock- on electron treatment   and – at high energies – bremsstrahlung and direct pair production (not a simple dE/ dx).
- Full accurate modeling of electromagnetic showers (EMS) with hadron/muon photo-production.
- Accurate transport from micron-size to ~30 nuclear interaction lengths.
-  Accurate tracking in magnetic field.
-  User-friendly geometry, histograming and GUI.
-  Interfaces to MAD, ANSYS and hydrodynamics codes.

_**FLUKA, GEANT4, MARS15**_

## Pion Yield Benchmarking: MARS15 vs E-910 and HARP

- MARS15 vs E910

- MARS15 vs HARP

- _Waiting for MIPP data_

- Recent developments in MARS15 and benchmarking: Coulomb scattering in LHydrogen
- (vs MUSCAT), nuclide mass/charge yields (vs GSI), heavy-ion collisions (boosting
- pion production; RIA, NASA, RHIC and LHC).

## Mercury Jet Target and Decay Channel Optimizations

- Thorough MARS optimization
- of / production and capture
- vs beam energy and size,
- target material, dimensions,
- tilt, and magnetic field value
- and profile, as well as of all
- other target system issues
- listed above.

- Jet breakup by beam, and MHD stabilization (BNL/FNAL)

- Using same tools, full modeling
- of 2003 Tevatron beam accident:
- beam dynamics, energy deposition,
- and ablation

## MERIT Experiment = MERcury Intense Target

_**A proof-of-principle test at CERN nTOF11 which will include (April 2007):**_
- A high-power intense proton beam: up to 2.8e13 protons (1-4 bunches) within a 2-s spill. Spot size r > 1.2 mm (rms): peak ED of 180 J/g.
- 15-T pulsed solenoid with a warm bore of 15 cm, cooled to 77 K by liquid nitrogen to reduce the resistance of its cooper coils (MIT).
- The Hg jet delivery system is being designed, built, and tested at ORNL. This system will generate a 1-cm-diameter mercury stream with velocities up to 20 m/s, tilted by 100 mrad
_**Experimental goals include (but not limited to):**_
- Studies of the Hg jet dispersal provoked by an intense pulse of a proton beam in a high solenoidal field; optical diagnostics (a set of four view-ports along the interaction region will be connected by imaging fiber-optic bundles to four high-speed cameras).
- Studies of the influence of entry angle on jet performance.
- Scintillation counters will monitor the flux of secondary pions produced during each of the each of the 1-4 bunches of a beam pulse to provide a measure of possible beam-induced reduction of density of the liquid jet.
- Confirm Neutrino factory/Muon Collider Targetry concept

## MERIT Schematic View

## Fermilab: MARS15 Modeling of MERIT Experiment 

- Fermilab: 1. MARS modeling (S. Striganov and NM): particle yields; fluxes, energy deposition, accumulated and residual dose in all the components, shielding
-                2. D. Jensen: scintillation counters.

## Target Tests Downstream FNAL pbar Target

- Pat Hurh, NM and BNL

- In Run-II: beam time is “free”, but space and access are limited
- Broad spectra and dynamic range: from 3 Mrad/pulse and 3e13 cm-2s-1
- Variety of irradiation conditions, e.g, emulating LHC-like in SC magnets
- Tight collaboration with BNL group who has expensive equipment and
-   experience for post-irradiation tests

- Available location

- Test module location

- DS end of PMAG

## Target Test Facility at AP-0

_**Significant interest from several groups:**_
** **
-  Targetry: high-power NuMI, shock studies for  NuFact (RAL, Sheffield, BNL), SNS-type Megawatt beams, etc
-  LHC/LARP collimation, instrumentation and  superconducting magnet materials
-  ILC collimator and positron source
-  Electronics, RIA, NASA etc

- AP-0 could be converted into full-scale Target Test Facility
- Some minor kicker changes could allow full NuMI beam to be delivered to tests at AP-0 (as NuMI operations allow)
- Just after Run II: 120 GeV, 0.5 Hz, 7.5-10 e12 ppp, Sigma 0.1 - 5 mm (2,000 - 3,000 J/g in Ni)
- After proton intensity upgrade (proton driver, proton accumulator): up to 2 MW, 0.75 Hz

_**BNL samples:**_

_**After Run II**_: