Abstract: Achieving compact, efficient and cost-
effective particle accelerators is an
overall goal of the community to help
propel future projects forward. In the
realm of the particle accelerators that
enable both the high-energy physics and
light source communities, achieving the
highest energy with the brightest beams
in the shortest distance is most
important and it is here where a
paradigm shift is needed. Achieving high
energies in a shorter distance (higher
gradients) than presently achievable is
important for even small laboratory
settings, i.e. universities or industries
desiring light sources, as it would permit
an affordable cost. While there are
several methods being considered for
compact, efficient particle accelerators,
we have chosen to pursue a unique
application of X-band (11.7 GHz) RF
cavities as they are capable, due to their
intrinsic high shunt impedance, of
generating high gradients with relatively
low input power. We have conceived of a
novel idea that can push the Colorado
State University’s (CSU) Advanced Beam
Laboratory’s beam energy up from the
present 6 MeV to over 25 MeV, without
the need of additional, expensive X-band
power sources. We call the concept a
co-linear X-band energy booster (CXEB)
and it relies on the use of X-band
structures powered by the beam that is
already available from the facility’s
existing L-band (1.3 GHz) linear
accelerator system. Also, we hope to use
this proposed system to provide beam to
a compact free-electron laser (FEL) at
CSU. The overall FEL system is quite
compact and comparatively cost-
effective given the fact that the existing
L-band infrastructure already exists.

Other than the challenge of reaching
higher energies in a reasonable distance
with higher gradients, one of the other
major modern challenges of modern
particle accelerators is in reaching high
intensities to explore exotic, low-
probability science. Our group is
involved in the Universities Research
Association (URA) Visiting Scholars
Award Program with Fermi National
Accelerator Laboratory (Fermilab). At
Fermilab, a major goal is achieving high-
intensity protons for the production of
high-intensity neutrinos. The main
beamline is the proton beamline and the
secondary beamline consists of a target
where protons collide in a fixed target to
create pions. The pions are focused and
subsequently decay to produce
neutrinos. To assist with these Fermilab
neutrino experiments, we have been
investigating the electromagnetic details
of the secondary beamline focusing
components of NuMI (Neutrinos and the
Main Injector), to further improve the
engineering designs. Both the NuMI
beam line, that has been providing
intense neutrino beams for several
Fermilab experiments (MINOS,
MINERVA, NOVA), and the newly
proposed LBNF (Long Baseline Neutrino
Facility) that plans to produce the highest
power neutrino beam in the world for
DUNE (the Deep Underground Neutrino
Experiment) need pulsed magnetic horns
to focus the pions. These horns are fed
pulsed high current through striplines
from the power supply. The magnetic
horn and high current stripline designs
have been evolving as NuMI reconfigures
for higher beam power and to meet the
needs of the LBNF design. We present
calculations and simulations using the
Poisson and ANSYS codes to evaluate
the electromagnetic interactions of the
high current stripline plates of the NuMI
Horn 1 at critical stress points in detail.
These results are being used to support
the development of new designs to
handle increased electric current and
higher beam power for NuMI upgrades
and for the LBNF.

Adviser: Stephen Milton
Co-Adviser: Sandra Biedron
Non-ECE Member: Alexander Brandl, ERHS
Member 3: Carmen Menoni, ECE
Addional Members:

Publications:
• Sipahi, T., Biedron, S., and Milton, S. "Frequency Domain Simulations of Co-linear X-band Energy Booster (CXEB) RF Cavity Structures and Passive RF Components with ACE3P." In 7th International Particle Accelerator Conference (IPAC'16) Proceedings, Busan, Korea, May 8-13, 2016, pp. 477-479. JACOW, Geneva, Switzerland, 2016.
• Sipahi, T., Biedron, S., and Milton, S. "Wakefield Excitation in Power Extraction Cavity (PEC) of Co-linear X-band Energy Booster (CXEB) in Time Domain with ACE3P." In 7th International Particle Accelerator Conference (IPAC'16) Proceedings, Busan, Korea, May 8-13, 2016, pp. 480-482. JACOW, Geneva, Switzerland, 2016.
• Sipahi, T., Biedron, S., Hylen, J., Milton, S., and Zwaska, R. "Simulations of High Current NuMI Magnetic Horn Striplines at FNAL." In 7th International Particle Accelerator Conference (IPAC'16), Busan, Korea, May 8-13, 2016, pp. 1230-1232. JACOW, Geneva, Switzerland, 2016.
• Sipahi, T., Biedron, S., and Milton, S. “Co-linear X- Band Energy Booster (XCEB) Cavity and RF System Details.”, In 6th International Particle Accelerator Conference (IPAC'15) Proceedings, Richmond, Virginia, USA, May 3-8, 2015, pp. 3421- 3424. JACOW, Geneva, Switzerland, 2015.
• Sipahi, T., Biedron, S., and Milton, S. “Achieving Higher Energies Via Passively Driven X-band Structures.”, In 5th International Particle Accelerator Conference (IPAC’14) Proceedings, Dresden, Germany, June 15-20, 2014, pp. 3933-3936. JACOW, Geneva, Switzerland, 2014.
• Milton, S., Biedron S., Harris, J., Martinez, J., D’Audney, A., Edelen J., Einstein, J., C. Hall, Horovitz, K., Morin, A., Sipahi, N., Sipahi, T., Williams, J., Carrico, C., and van der Slot, P.J.M. “Colorado State University (CSU) Accelerator and FEL Facility.”, In 5th International Particle Accelerator Conference (IPAC’14) Proceedings, Dresden, Germany, June 15-20, 2014, pp. 3937-3939. JACOW, Geneva, Switzerland, 2014.
• Sipahi, T., Sipahi, N., Biedron, S., and Milton, S. “X-band RF Power Generation via an L-band Accelerator System and Uses” Directed Energy Professional Society (DEPS) 16th Annual Directed Energy Symposium Proceedings, Huntsville, Alabama, March 10-14, 2014.
• Sipahi, N., Sipahi, T., Biedron, S., and Milton, S. “X-band RF power Generation via L-band Accelerator System and Uses.”, In 25th North American Particle Accelerator Conference (NA-PAC’13) Proceedings, Pasadena, California, USA, Sept. 29-Oct. 4, 2013, pp. 951-953. JACOW, Geneva, Switzerland, 2014.
• Sipahi, T., Sipahi, N., Biedron, S., and Milton, S. “Passively Driving X-Band Structures to Achieve Higher Beam Energies.”, In 25th North American Particle Accelerator Conference (NA-PAC’13) Proceedings, Pasadena, California, USA, Sept. 29 – Oct. 4, 2013, pp. 1001-1003. JACOW, Geneva, Switzerland, 2014.
• Milton, S., Biedron S., Harris, J., Martinez, J., D’Audney, A., Edelen J., Hall C., Horovitz K., Morin A., Rand L., Sipahi N., Sipahi, T., Williams, J., Medicine Bear, S., Carrico, C., Moin, N., Van Keuren, J., van der Slot, P.J.M., Bos, A., Dong, A., Kang, L., Kenny, K., Smith. J. “Status of the CSU Accelerator and FEL Facility”, Directed Energy Professional Society (DEPS) Fourth Annual Advanced High-Power Lasers Meeting Proceedings, Santa Fe, New Mexico, USA, June 24-27, 2013.
• Sipahi, N.*, Sipahi, T.*, Biedron, S., Milton, S. and Adolphsen C. “Passively Driving X-band Structure to Achieving Higher Beam Energies”, In 6th International Particle Accelerator Conference (IPAC’13) Proceedings, Shanghai, China, May 12-17, 2013, pp. 1304-1306. JACOW, Geneva, Switzerland, 2013.
• Milton, S., Biedron, S., Burleson, T., Carrico C., Edelen, J., Hall, C., Horovitz, K., Morin, A., Rand, L., Sipahi, N., Sipahi, T., van der Slot, P.J.M., Dong, A., Yehudah, H., “The CSU Accelerator and FEL Facility”, 34th International Free Electron Laser Conference (FEL 2012), Nara, Japan, Aug. 26-31, 2012, pp. 373-376. JACOW, Geneva, Switzerland, 2012.

Program of Study:
ECE581A3
ECE680A3
ECE680A4
ENGR697
PHYSICS745
ERHS530
ECE799
GSTR600