Walter Scott, Jr. College of Engineering

Graduate Exam Abstract

Taylan Sipahi
Ph.D. Final
Mar 08, 2017, 10:30 am - 1:00 pm
ERC Electronic Classroom A210
Beam-Driven Co-linear X-band Energy Booster (CXEB) for a Compact FEL and Improvements to the Engineering of High-Current Pulsed Magnetic Horn Systems
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 light source and the high-
energy physics 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 beam energy
up from the present 5 MeV to over 20
MeV, without the need of an additional,
expensive X-band power source
(klystron). 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). 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) and the newly
proposed LBNF (Long Baseline
Neutrino Facility), 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-the most powerful in
US and the longest in the world), and
LBNF 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 the evaluation of the
electromagnetic interactions of the
high-current striplines of the NuMI
Horn 1 at critical stress points in detail.
Additionally, the current on the
focusing part of a pulsed magnetic
horn needs to be quite uniform, which
would not be the case if the current
leads are at points/lines as presently.
Therefore some system is needed to
achieve the uniform distribution. We
optimize the necessary length of a
uniform equalization section to achieve
a certain level of uniformity and
consider (analyze and model) alternate
geometries for equalization that are
sculpted to achieve quicker
equalization, or convoluted to achieve
more compact convolution. 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: N/A
Publications:
• Sipahi, T., Milton, S., and Biedron, S. "Co-linear X-band Energy Booster (CXEB) for a Compact FEL" will be submitted to Physical Review Accelerators and Beams (PRAB) in February 2017.
• Sipahi, T., Milton, S., and Biedron, S. " Wakefield Excitation In Power Extraction Cavity of Co-Linear X-Band Energy Booster in Time Domain with ACE3P", In 2016 North American Particle Accelerator Conference Proceedings (NAPAC’16), Chicago, IL, USA, October 9-14, 2016. (pre-press)
• Sipahi, T., Milton, S., and Biedron., S. "Frequency Domain Simulations of RF Cavity Structures and Coupler Design for Co-linear X-band Energy Booster (CXEB) with ACE3P”, In 2016 North American Particle Accelerator Conference Proceedings NAPAC’16, Chicago, IL, USA, October 9-14, 2016.
• Sipahi, T., Biedron, S., Hylen, J., Milton, S., and Zwaska, R. "Simulations Of High Current Magnetic Horn Striplines at Fermilab", In 2016 North American Particle Accelerator Conference Proceedings NAPAC’16, Chicago, IL, USA, October 9-14, 2016.
• Sipahi, T., Biedron, S., Hylen, J., Milton, S., and Zwaska, R. "High Current Striplines for Neutrino Beams.", In 6th Euro-Asian Pulsed Power Conference (EAPPC 2016) with the 21st International Conference on High-Power Particle Beams (BEAMS) and the 15th International Conference on Megagauss Magnetic Field Generation and related topics (MEGAGAUSS) proceedings, Estoril, Portugal, 18-22 September, 2016.
• Sipahi, T., Biedron, S., Hylen, J., Milton, S., and Zwaska, R. "Simulations Of High Current NUMI Magnetic Horn Striplines at FNAL.", In 38th International Conference on High Energy Physics (ICHEP 2016), August 3-10, 2016, Chicago, Illinois, USA.
• 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