Christoph Steier

1995: Obtained the degree ‘Diplom-Physiker’ (mostly equivalent to Master of Science) from Bonn University; title of the diploma thesis: ‘Theoretische und experimentelle Untersuchungen zu Vielteilcheneffekten bei der Elektronen-Stretcher-Anlage ELSA’ (Theoretical and experimental studies concerning collective phenomena at the Electron Stretcher Accelerator ELSA)

1999: Obtained the degree ‘Dr. rer. nat.’ (equivalent to PhD) from the Rheinische-Friedrich-Wilhelms Universität in Bonn (Bonn University, Germany); title of the PhD thesis: ‘Polarisierte Elektronen in der Elektronen-Stretcher-Anlage ELSA’ (Polarized Electrons in the Electron Stretcher Accelerator ELSA)

My major research activities have been in the design, study, optimization and operation of storage rings. The contributions have been theoretical, computational, as well as experimental across all areas of accelerator physics and also involved many hardware projects. The goal was to substantially improve the accelerator performance of several facilities. This included work to increase the beam intensity or reduce the beam emittance, both leading to higher luminosity or brightness, work to enable new characteristics like polarized beams or special (ultrashort) time structures, work to improve stability and thereby enable ultra-sensitive experiments, or work to improve operational excellence and reliability. The performance and upgrade history of the ALS as well as the advanced technology and physics design behind ALS-U are the main manifestations of this work.

I was the System manager for ALS-U Accelerator Systems throughout the R&D and design phase, responsible for the design, manufacturing and commissioning of the ALS-U accelerator, and am now the ALS-U System Manager for Accelerator Physics and Commissioning.

C. Steier, “Possibilities for a Diffraction-Limited Upgrade of a Soft X-ray Light Source”, Synchrotron Radiation News, Volume 27, Issue 6, 2014, doi:10.1080/08940886.2014.970934.

C Steier et al 2014 J. Phys.: Conf. Ser. 493 012030 doi:10.1088/1742-6596/493/1/012030, “Completion of the Brightness Upgrade of the ALS”

M. Hertlein, A. Scholl, A. Cordones, J. Lee, K. Engelhorn, T. Glover, B. Barbrel, C. Sun, C. Steier, G. Portmann and D. Robin, “X-rays only when you want them: optimized pump-probe experiments using pseudo-single-bunch operation”, 2015 J. Synchrotron Rad. 22, 729-735.

C. Sun, et al., Small-emittance and low-beta lattice designs and optimizations, Phys. Rev. ST Accel. Beams 15, 054001

M. Bei, M. Borland, Y. Cai, P. Elleaume, R. Gerig, K. Harkay, L. Emery, A. Hutton, R. Hettel, R. Nagaoka, D. Robin, C. Steier, The Potential of an Ultimate Storage Ring for Future Light Sources, Nucl. Inst. & Meth. A, 622, 3 (2010) 518-535, doi:10.1016/j.nima.2010.01.045.

C. Steier, et al., Lattice and Emittance Optimization Techniques and the ALS Brightness Upgrade, Nucl. Inst. & Meth. A, doi:10.1016/j.nima.2010.11.077

C. Steier, et al., Successful Completion of the ALS Top-off Upgrade, AIP conference proceedings of SRI 2009, 10th International Conference on Radiation Instrumentation, Melbourne, Australia (2009)

L. Yang, D. Robin, F. Sannibale, C. Steier, Weishi Wan, Global optimization of an accelerator lattice using multiobjective genetic algorithms, Nucl. Instr. & Meth. A, 609, 1 (2009) 50-57, doi:10.1016/j.nima.2009.08.027.

D. Robin, J. Krupnick, R. Schlueter, C. Steier, S. Marks, B. Wang, J. Zbasnik, et al., Superbend upgrade of the Advanced Light Source, Nucl. Instrum. Meth. A 538, 1-3 (11 February 2005), 65-92

C. Steier, et al., Measuring and Optimizing the Momentum Aperture in a Particle Accelerator, Phys. Rev. E 65, 056506 (2002)

J. Byrd, W. P. Leemans, A. Loftsdottir, B. Marcelis, Michael C. Martin, W. R. McKinney, F. Sannibale, T. Scarvie, and C. Steier, Observation of broadband self-amplified spontaneous coherent terahertz synchrotron radiation in a storage ring, Phys. Rev. Lett. 89, 22, 224801 (2002)

D. Robin, C. Steier, J. Laskar, L. Nadolski, Global dynamics of the Advanced Light Source revealed through experimental frequency map analysis}, Phys. Rev. Lett., 85, 3, 558 (2000)

S. Nakamura et al., Acceleration of polarized electrons in ELSA, Nucl. Instr. and Meth. A 411 (1998) 93