**Simulation of High Power Targets for Future
Accelerators**

**PI:
Roman Samulyak (SBU / BNL)**

**Collaborators:
K. McDonald (Princeton University), H. Kirk (BNL)**

**Source
of support:** DOE HEP (completed
in FY15)

The targetry
group of DOE's Muon Accelerator
Program (MAP) is exploring the feasibility
of high power liquid mercury targets for future particle
accelerators. The
numerical simulations aim to describe the hydrodynamic
response of the target
interacting with proton pulses in magnetic fields and provide
input for the
design of reliable targets. Simulations use FronTier,
a multiphysics code with explicit
resolution of
material interfaces based on front tracking, a smooth particle
hydrodynamics
code, and a newly developed Largangian
particle code
that significantly improves accuracy of previous
particle-based methods. We
have performed simulations of liquid mercury jet targets
interacting with high
power proton beams in magnetic fields. MHD simulations which
predicted strong
distortion of the jet entering a 15 Tesla solenoid and the
reduction of the
target efficiency have led to a
change of design
parameters for the CERN MERIT experiment. Simulation
also predicted
strong instabilities and cavitation of the mercury jet
interacting with proton
pulses at zero magnetic field, and
a stabilizing
effect of the magnetic field. The main conclusion of the targetry
program is that liquid mercury jet targets can reliably work
in future
accelerators and neutron sources up to 8 MW power limit. This
research resulted
in unique computational tools that will be able to serve as a
design tool for
future accelerator and neutron source targets.

Mercury
jet target disintegration after interaction with 24 GeV,
12 teraproton
bunch. Left:
experiment, right: simulation.

_{}

Experimental
images of mercury thimble experiments: mercury splash at t =
0.88, 0.125, 0.7 ms after impact
of 12 teraproton
beam (A. Fabich)

Particle-based
simulation of mercury thimble experiments: mercury splash at t
= 0.5 and 0.7 ms

**Recent
Publications:**

1.
T.
Guo, S. Wang, R. Samulyak,
Sharp interface algorithm for large density ratio
incompressible multiphase magnetohydrodynamic,
Procedia
Comp. Science, 18 (2013), 511 - 520.

2.
R.
Samulyak, H.C. Chen, H. Kirk, K.
McDonald, Simulation
of high-power mercury jet targets for neutrino factory and muon
collider, Proceedings of PAC2013, Pasadena, CA USA, paper
TUPBA09.

3.
R.
J. Abrams et. al.,
International
design study for the Neutrino Factory, interim design report,
2011. BNL-96453-2011; CERN-ATS 2011-216

4.
R.
Samulyak, W. Bo, X. Li, K.
McDonald, H. Kirk,
Computational algorithms for multiphase magnetohydrodynamics
and applications, Condensed Matter Physics, 13 (2010), No 4,
43402: 1 - 12.

5.
S.
Wang, R. Samulyak, T. Guo,
An embedded boundary method for parabolic problems with
interfaces and
application to multi-material systems with phase transitions,
Acta Mathematica
Scientia, 30B (2010), No. 2, 499 -
521.

6.
H.G.
Kirk, R. Samulyak, N. Simos,
T. Tsang, I. Efthymiopoulos, A. Fabich,
H. Haseroth, F. Haug, J. Lettry,
V.B. Graves, P.T. Spampinato,
K.T. McDonald, J.R.J. Bennett and T.R. Edgecock,
A
proof-of-principal experiment for a high-power target system,
BNL report BNL-82153-2009-CP,
2009.

7.
J.
Du, T. Lu, R. Samulyak,
Algorithms for magnetohydrodynamics
of ablated materials, Journal of Nanoscience
and Nanotechnology, 8 (2008), 3674 - 3685.

8.
R.
Samulyak, J. Du, J. Glimm,
Z. Xu, A numerical algorithm for
MHD of free surface ows at low
magnetic Reynolds numbers, J. Comp. Phys., 226
(2007), 1532 - 1549.

9.
T.
Lu, R. Samulyak, J. Glimm,
Direct numerical simulation of bubbly flows and its
application, J. Fluid Eng.,
129 (2007), 595 - 604.

10.
R.
Samulyak, T. Lu, Y. Prykarpatskyy, J.
Glimm, Z. Xu, M.N. Kim, Comparison of heterogeneous and
homogenized numerical
models of cavitation, Int. J. Multiscale
Comp. Eng., 4 (2006), No 3, 377 - 389.