ACCELERATOR PHYSICS AT NORTHERN ILLINOIS UNIVERSITY Courtlandt L. Bohn Northern Illinois University Department of Physics (as of 15 August 2005)

Proximity to Two Major Laboratories NIU FNAL ANL 0 10 km

Aerial View of University (location: DeKalb, Illinois) Aerial View of University (location: DeKalb, Illinois)

Faraday Hall: Home of Physics Department

Beam Physics and Astrophysics Group Main Interests Beam Physics and Astrophysics Group Main Interests  Production of high-brightness beams (electron, hadron)  High-resolution electron-beam diagnostics: interferometry (transition radiation) electro-optic sampling (electromagnetic fields)  Theory and simulation of space charge: chaos in time-dependent systems mixing in N-body systems (beams, galaxies) multiresolution analysis (wavelet-based algorithms)  Production of high-brightness beams (electron, hadron)  High-resolution electron-beam diagnostics: interferometry (transition radiation) electro-optic sampling (electromagnetic fields)  Theory and simulation of space charge: chaos in time-dependent systems mixing in N-body systems (beams, galaxies) multiresolution analysis (wavelet-based algorithms)

Beam Physics and Astrophysics Group People Beam Physics and Astrophysics Group People  Faculty: Court Bohn, Bela Erdelyi, Philippe Piot  Postdocs: Daniel Mihalcea, Ioannis Sideris, Balša Terzić  Graduate Students: Greg Betzel, Marwan Rihaoui, Ily Vass  Many collaborators For more information, see  Faculty: Court Bohn, Bela Erdelyi, Philippe Piot  Postdocs: Daniel Mihalcea, Ioannis Sideris, Balša Terzić  Graduate Students: Greg Betzel, Marwan Rihaoui, Ily Vass  Many collaborators For more information, see

Beam Physics and Astrophysics Group Beowulf PC Cluster Beam Physics and Astrophysics Group Beowulf PC Cluster  56 dual-processor nodes linked via 100 Mbit network  Server: 1GB RAM, 2x Athlon 2600+, shared 1.5TB raid array  Worker nodes: 1GB RAM/node, Amd Opteron 1800 (2x15 nodes), Amd Atlon 2400+(2x24), 1800+(2x16), shared disk space: 4.5TB  Software: PV-WAVE (visualization, data analysis) ROOT (analysis of large data bases), LAM (enables parallel processing) CONDOR (managing batch jobs)  56 dual-processor nodes linked via 100 Mbit network  Server: 1GB RAM, 2x Athlon 2600+, shared 1.5TB raid array  Worker nodes: 1GB RAM/node, Amd Opteron 1800 (2x15 nodes), Amd Atlon 2400+(2x24), 1800+(2x16), shared disk space: 4.5TB  Software: PV-WAVE (visualization, data analysis) ROOT (analysis of large data bases), LAM (enables parallel processing) CONDOR (managing batch jobs)

Beowulf PC Cluster 56 nodes  112 CPUs in a climate-controlled room

Status:Funding is in hand to build the Lab; equipment is on order Plans:Electron gun (borrowed from Argonne) Titanium-Sapphire femtosec-class laser (to be purchased) UHV preparation capability State-of-the-art electronics and controls

Context of Accelerator Physics Program  Electron photoinjectors and linacs for Linear Collider (Fermilab) X-ray FEL (Argonne) high-average-power FEL (Argonne, Jefferson Lab)  Hadron linear accelerators for isotope production (Argonne, Fermilab?) neutrino physics (Fermilab)  Proton booster synchrotron with high current for neutrino physics (Fermilab)  Electron photoinjectors and linacs for Linear Collider (Fermilab) X-ray FEL (Argonne) high-average-power FEL (Argonne, Jefferson Lab)  Hadron linear accelerators for isotope production (Argonne, Fermilab?) neutrino physics (Fermilab)  Proton booster synchrotron with high current for neutrino physics (Fermilab)

Overview of Experiments and Hardware Development Overview of Experiments and Hardware Development

Fermilab/NICADD Photoinjector Laboratory  Electron source at A0  Jointly operated by Fermilab/NICADD  Beam Physics  International Facility (Chicago, Cornell, Georgia, Michigan, NIU, Rochester, UCLA, Fermilab, DESY, LBL, INFN Milan)

Longitudinal density profile of compressed 3 nC bunches: measured (red) vs. PARMELA with 20,000 particles (blue). Longitudinal Density Profile via Interferometry of Coherent Transition Radiation

Electro-Optical Sampling Proof-of-principle experiment (and Univ. of Rochester Ph.D. dissertation for M. Fitch): Measured beam-induced wakefield of 6-way cross. Goal for future work: Measure beam field directly (not wakefield) to infer the beam density profile. A key: need low-impedance vacuum chamber. Ultimate objective: Noninvasive bunch monitor

Overview of Theory Program (more information can be found in Group publications) Overview of Theory Program (more information can be found in Group publications)

NONEQUILIBRIUM BEAM: A CARTOON

Transient Chaos in a Breathing Bunch log 10 |f(t)| vs. t

Impact of Unavoidable Noise on Halo Breathing mode Internal mode (oscillating envelope) (stationary envelope) Both the topology of the mode(s) and the strength of the noise are important to halo formation. Breathing mode Internal mode (oscillating envelope) (stationary envelope) Both the topology of the mode(s) and the strength of the noise are important to halo formation.  |  |  = 10 -3

Wavelets (a)Haar wavelet, (b) Morlet wavelet, (c) Daubechies wavelet. 1D Daubechies least symmetric N = 10 two-dimensional wavelet. 2D

Fermilab/NICADD Photoinjector Simulations rms beam radius (mm) rms normalized transverse emittance (μm) rms bunch length (mm) rms normalized longitudinal emittance (ps-keV)

Simulations of AES/JLab Photoinjector Green Function + Fast Fourier Transform Wavelets + Preconditioning

Summary  Northern Illinois University is serious about accelerator physics  Focus is basic research, especially as concerns: Production, measurement of high-brightness beams Fundamental understanding of space-charge dynamics Improved simulation codes to include multiscales, halo  In-house facilities are in place for theory, computations, and small-scale laboratory work  Many collaborations are in place, including with Fermilab and Argonne  We seek excellent students who are likewise serious!  Northern Illinois University is serious about accelerator physics  Focus is basic research, especially as concerns: Production, measurement of high-brightness beams Fundamental understanding of space-charge dynamics Improved simulation codes to include multiscales, halo  In-house facilities are in place for theory, computations, and small-scale laboratory work  Many collaborations are in place, including with Fermilab and Argonne  We seek excellent students who are likewise serious!

We plan shortly to establish a special fellowship: The NICADD Fellowship in Accelerator Physics  Very competitive: for especially gifted students  At most 2 recipients per year  Annual stipend of ~$30,000  Full tuition waiver We plan shortly to establish a special fellowship: The NICADD Fellowship in Accelerator Physics  Very competitive: for especially gifted students  At most 2 recipients per year  Annual stipend of ~$30,000  Full tuition waiver Announcement