Give


Graduate Exam Abstract


Taylan Sipahi

Ph.D. Final

March 8, 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