O'Shea, Patrick G.
Institute for Research in Electronics & Applied Physics
Space Charge Dreams (by Chip Simons)
Professor O'Shea is Principal Investigator in the Bright Beams Collective Research Group
He was born in Cork, Ireland, and holds a BSc degree in Experimental Physics from the National University of Ireland, University College Cork, and MS and PhD degrees in Physics from the University of Maryland.
In recognition of significant achievements in education and research, he has been elected a Fellow of the Royal Society for the Arts, American Association for the Advancement of Science, American Physical Society, Institute of Electrical and Electronic Engineers, Irish Academy of Engineering, and won the University of Maryland's Distinguished Scholar-Teacher Award.
Professor O’Shea’s technical expertise lies in the field of applied electromagnetics, nonlinear dynamics, and charged particle beam technology, and applications.
Professor O'Shea has previously served as:
President of University College Cork, Ireland,
Vice President for Research at the University of Maryland,
Chair of the Department of Electrical & Computer Engineering at the University of Maryland’s A. James Clark School of Engineering.
Director of the Institute for Research in Electronics and Applied Physics (IREAP) at the University of Maryland.
Faculty member at Duke University
Project Leader at the University of California Los Alamos National Laboratory.
- President Emeritus, University College Cork, Ireland
- Royal Society for the Arts, Fellow
- American Association for the Advancement of Science, Fellow
- Distinguished Scholar-Teacher, University of Maryland
- Irish Academy of Engineering, Fellow
- Alan Berman Research Publication Award, U.S. Naval Research Laboratory
- American Physical Society, Fellow
- Institute for Electrical and Electronic Engineering, Fellow
- Distinguished Project Team Award, Los Alamos National Laboratory
- Leadership Maryland
The University of Maryland Electron Ring (by Tim Koeth)
Dr. O'Shea's current research is in the area of charged particle beam technology, electromagnetics, and their applications.
- Demonstrated space-charge limited current phenomena in the propagation of high-current low energy electron beams in solenoidal and gas-focused regimes
- Demonstrated and studied an advanced accelerator concept known as the laser-controlled collective ion accelerator. Achieved an accelerating gradient for protons of 30 MV/m
- Developed record high brightness 1-MeV H-, and Ho beams on Beam Experiments Aboard Rocket (BEAR) test stand.
- Demonstrated autonomous operation of a directed energy experiment in space using radio-frequency quadrupole H- accelerator. Studied propagation Ho, H-, and H+ beams in geomagnetic ﬁeld at an altitude of 200 km
- Demonstrated a high-current radio-frequency photocathode electron source as a driver for a high-gain infrared free-electron laser - ﬁrst operation of a high-current RF photoinjector coupled to a linear accelerator.
- Demonstrated operation of electron photoinjector with space-charge emittance compensation whose brightness exceeded that of conventional sources by two orders of magnitude. Experimental conﬁrmation of the theory of space charge emittance growth compensation.
- Demonstrated free-electron lasing from 370 nm to 11 µm using low-energy, high-brightness electron beam, and achieved a record short wavelength for a linear accelerator-driven FEL
- Member of the team that demonstrated inverse Compton γ-ray production using an FEL
- Developed a theory of reversible and irreversible emittance growth
- Electron beam production of medical radioisotopes
- Developed the nitrogen-laser driven RF photoinjector
- Compact electron ring (UMER), an analog computer for beam physics studies in the space charge dominated regime; thermodynamics of beams and energy transfer mechanisms in beam systems. Discovery of solitary waves in electron beams.
- Developed dispenser photocathode electron source.
Bright Beams Collective
We believe that a bright beam is a better beam. By “beam” we mean a swarm of charged particles (electrons or ions) that is collectively heading off to do something useful. The nonlinear dynamics of these swarms are really interesting. Understanding the swarms is important for many applications, including high energy physics accelerators; particle-beam-driven high-energy-density physics, inertial fusion energy; applications to galactic dynamics; and free-electron light sources.
The group began exploring space-charge-dominated beams (intense swarms) in the 1980s under the direction of the late Professor Martin Reiser.
Today, the Bright Beams Collective (BBC) Research Group hosts world-class research facilities for collective beam dynamics and accelerator technology at the Institute for Research in Electronics and Applied Physics of the University of Maryland, College Park. Using scaled low-energy electron beams, our UMER electron ring and LSE linear facilities cleverly access the intense, high-brightness regime of beam operation in accelerators at a much lower cost than larger and more energetic machines. Therefore, we have ideal testbeds for exploring how to enhance the brightness of beams of existing and future accelerators.
Our BBC research explores the physics of charged particle beams at the extreme frontier of intensity. For many applications, the intensity or luminosity frontier is as vital as the energy frontier. Examples of such applications include high-luminosity colliders, spallation neutron sources, and X-ray-free electron lasers and related intense light sources, high-average-power-free electron lasers, and future heavy ion-driven inertial fusion concepts.
Research Areas of Interest
- Experimental beam physics
- Nonlinear accelerator optics
- Ring physics
- Space charge in beams
- Advanced beam diagnostics
- Beam halo
- Nonlinear dynamics
Our research is supported by the U.S. Department of Energy, Office of Science.
Some interesting publications
P.G. O’Shea and H. P. Freund, Science, 292, 1853 (2001)
C. Hernandez-Garcia, M. Stutzman, and P. G. O'Shea Physics Today, February 2008, page 44
Y.C. Mo, R.A. Kishek, D. Feldman, I. Haber, B. Beaudoin, P.G. O'Shea, and J.C.T. Thangaraj, Physical Review Letters 110, 084802 (2013).
S. Bernal, B.L. Beaudoin, T. Koeth, and P.G. O'Shea, Physical Review Special Topics - Accelerators & Beams 14, 104202 (2011).
B. Beaudoin, I. Haber, R.A. Kishek, S. Bernal, T. Koeth, D. Sutter, P.G. O'Shea, and M. Reiser, " Physics of Plasmas 18, 013104 (2011).
K. Tian, R.A. Kishek, I. Haber, M. Reiser, and P.G. O'Shea, Physical Review Special Topics - Accelerators & Beams 13, 034201 (2010).
D. Stratakis, R.A. Kishek, I. Haber, R.B. Fiorito, M. Reiser, and P.G. O'Shea Journal of Applied Physics 107, 104905 (2010)
K. L. Jensen, P. G. O'Shea, D. W. Feldman, and J. L. Shaw, J. Appl. Phys. 107, 014903 (2010)
J.G Neumann, R.B. Fiorito, P.G. O'Shea, H. Loos, B. Sheehy, Y. Shen, Z. Wu, J. Appl. Phys. 105, 053304 (2009)
D. Stratakis, R.A. Kishek, R.B. Fiorito, K. Tian, I. Haber, P.G. O'Shea, M. Reiser, and J.C.T. Thangaraj,12, 020101 (2009).
J.R Harris, P.G. O’Shea, Phys. Plasmas 15, 123106 (2008)
M.A. Holloway, R.B. Fiorito, A.G. Shkvarunets, P. G. O’Shea, S.V. Benson, D. Douglas, P. Evtushenko, and K. Jordan, Phys. Rev. ST Accel. Beams 11, 082801 (2008)
K L Jensen, BL Jensen, EJ Montgomery, DW Feldman, PG O'Shea, and NA Moody, J. Appl. Phys. 104, 044907 (2008)
K L. Jensen, Y. Y. Lau, D. W. Feldman and P. G. O’Shea, Phys. Rev. ST Accel. Beams 11, 081001 (2008)
KL Jensen, JJ Petillo, EJ Montgomery, ZG Pan, DW Feldman PG O'Shea, NA Moody, M. Cahay, JE Yater, JL Shaw J. Vac. Sc. & Tech B, 26, 831 (2008)
J. R. Harris and P. G O'Shea, Journal of Applied Physics. 103, 113301 (2008)
J. R. Harris, J. G. Neumann, K. Tian, and P. G. O’Shea, Phys. Rev. E, 76 026402 (2007)
K. L. Jensen P. G. O'Shea, D. W. Feldman, and N. A. Moody, Applied Physics Letters. 89, 224103 (2006)
Kevin L. Jensen, Donald W. Feldman, Nathan A. Moody, and Patrick G. O'Shea, J. Appl. Phys. 99, 124905 (2006)
Kevin L. Jensen, Donald W. Feldman, Nathan A. Moody, and Patrick G. O'Shea, Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures 863, (2006)
J.R. Harris and P.G. O'Shea, IEEE Transactions on Electron Devices 53(11), 2824-2829 (2006).
K. Tian, Y. Zou, Y. Cui, I. Haber, R. A. Kishek, M. Reiser, and P. G. O’Shea, Physical Review. ST Accel. Beams 9, 014201 (2006)
J. R. Harris, J. G. Neumann, and P. G. O'Shea, J. Appl. Phys. 99, 093306 (2006)
Bernal, H. Li, R. A. Kishek, B. Quinn, M. Walter, M. Reiser, P. G. O’Shea, and C. K. Allen. Phys. Rev. ST Accel. Beams 9, 064202 (2006)
H.P. Freund, P.G. O’Shea, S. Biedron, Physical Review Letters, 94, 074802 (2005)
Y. Zou, Y. Cui, M. Reiser, and P. G. O'Shea, Physical Review Letters, 94, 134801 (2005)
K. L. Jensen, D. W. Feldman, and P.G. O’Shea, Applied Physics Letters. 85, 5448 (2004)
H. P. Freund and P.G. O’Shea, Physical Review Letters, 84 2861 (2000)
Other professional society fellows
- Royal Society for the Arts
- Irish Academy of Engineering