BESAC

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From Quark Confinement to Synchrotron
Radiation and Microwave Superconductivity to
Terahertz Spectroscopy
Possibilities of graduate research in/with
accelerators, particle and photon beams, free
electron lasers and microwave superconductivity
at Jefferson Lab
Swapan Chattopadhyay Jefferson Lab August 15, 2003
Seminar ORNL August 15, 2003
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• From Quark Confinement to Synchrotron Radiation
• and
• Microwave Superconductivity to Terahertz
  Spectroscopy
•  
• Possibilities of graduate research in/with
  accelerators, particle and
• photon beams, free electron lasers and microwave
  superconductivity
• at
• Jefferson Lab
•   
• Swapan Chattopadhyay
• Thomas Jefferson National Accelerator Facility
• After a brief overview of Jefferson Lab, I will
  outline the scientific reach of its facilities
  and the research and development of the enabling
  technologies behind them. Study of the strong
  force in nature by direct excitation of the
  glue that binds the fundamental quarks
  requires an understanding of the generation and
  control of a continuous train of intense
  electromagnetic wave field in superconducting
  microwave cavities and presents a fascinating new
  dynamical problem of control in a nonlinear,
  dissipative and dispersive system with memory.
  The mechanisms of acceleration of and
  radiation from a charged particle are
  fundamentally coupled. Working on intense charged
  particle beams via microwave fields and
  recovering the energy back for enhanced
  efficiency, requires precise manipulation of
  six-dimensional phase space of a many-body
  dynamical system interacting with self -generated
  coherent radiation fields. Yet the same self-
  interaction leads to phase-space bunching and the
  possibility of generating Terahertz radiation of
  unprecedented intensity and brightness. Novel
  radiation sources would have prized applications
  in studies of collective dynamics of condensed
  and soft matter. The long wavelength radiation
  when focused tightly leads to ultrashort bursts
  of energy and intense electromagnetic fields
  opening up new possibilities in high field atomic
  and molecular physics. As we discuss these
  fascinating ideas, possible graduate thesis
  topics in physics, applied physics, electrical
  and control engineering will be brought out along
  the way.

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Jefferson Lab Site
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Jefferson Lab Strategic Vision
Nuclear Physics
Nucleus
Nucleon
Quark
Gluon
Grand Instruments for Science
gt12 GeV/EIC
6 GeV
12 GeV
FEL
Photon Science and Applications
Complex Materials
Precision Dynamics
Nano-systems
Surface Processing
Bio-systems
Development of Unique Scientific/Technical Tools
Imaging and Instrumentation (Medical/Security)
Advanced Computational Science (LQCD)
10 Tflop ? 100 Tflop ? 1 Pflop
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Canvas of science-driven accelerator based light
sources
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Jefferson Lab Accelerator Site
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South Linac Cryomodules in Tunnel
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Hall A Electron and Hadron Spectrometers
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Hall B CEBAF Large Acceptance Spectrometer
(CLAS)
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Hall C High Momentum Spectrometer and Short
Orbit Spectrometer
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The JLab IR Demo Laser
The JLab IR Demo Laser the worlds most powerful
femtosecond laser the worlds most powerful
tunable IR laser
Wiggler
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JLab is the Leading International Facility in
Hadronic Physics

• Our approved research program involves half of
  our 2100 member user community
• 1011 scientists from 167 institutions in 29
  countries

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Accelerator Physics Collaborations


Daresbury 4 GLS
DESY/TESLA Hamburg

MSU

Cornell


FNAL


ANL
BNL
LBNL/LLNL

JLab

ORNL
5 RHIC II (BNL) 6 Femtosource (LBNL, LLNL) 7
SNS (ORNL)
1 RIA (MSU, ANL) 2 TESLA (DESY, FNAL)
3 ERL Prototype (Cornell) 4 4 GLS (Daresbury)
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Continuous Electron Beam Accelerator Facility
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Whats the Point of 12 GeV Upgrade?
Courtesy Alex Dzierba Leigh Harwood

• The 12 GeV Upgrade at Jefferson Lab aims at
  answering two core questions
• 1) What is the nature of quark confinement?
• 2) What is the fundamental nature of the nuclear
  force in terms of quark and gluon interactions?

Quark Confinement
Hall D
Analytical model (based on QCD) of nuclei as
groups of quarks
Halls A, B, C
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Quark Confinement

• Quarks are the only particles known that cannot
  be observed as individuals. They always occur in
  groups.
• This is known as quark confinement.

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Quark Confinement (contd)

• Current wisdom Fq-q k

Uq-q kr
Implication Field energy always increases as the
quarks separate
Quark Confinement
There is some separation distance at which
field energy Exceeds the mass of 2 quarks.
Can be reduced by creating
quark-antiquark pair.
Never find an isolated quark.
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Quark Confinement (contd)
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How to See the Flux Tubes
Flux tube
2 quarks 1 meson Spectrum is known.
Flux tube has its own quantum numbers
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Color Mapping in QCD
NUCLEAR PARTICLE PHYSICS
Graduate Research!!
t ltlt 10-18 sec.
Strategic Simulation Lattice-gauge QCD Code
Possible at JLabs 12 GeV Upgrade of CEBAF.
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6 GeV CEBAF
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RF Control

• Overall performance requirements
• Amplitude 1x10-4
• Phase 0.1º

• Algorithm choice
• Large Lorentz forces
• Narrow bandwidth
• Detuning curve is VERY different.

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Lorentz Detuning Effects
Tuner must run ? slow
Is there an alternative?
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RF Control (contd)
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RF Control (contd)
Graduate Research topic!! Applied Math, EE,
Nonlinear Dynamics!

• Algorithm for Amplitude and Phase Control.

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Energy Recovery and its Potential
First high current energy recovery experiment at
JLab FEL, 2000

• 2 kW average power
• 26.5 microns
• 500 femtosecond pulses
• 75 MHz rep rate

JLab ERL-based Free Electron Laser
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First Energy Recovery Experiment at High Energy
at CEBAF, April 2003
Beam profiles at end (SL16) of South Linac
Gradient modulator drive signals with and without
energy recovery in response to 250 ?sec beam
pulse entering the rf cavity
1 GeV Accelerating beam
100 MeV Decelerating beam
Energy Ratio of up to 150 tested at CEBAF (20
MeV 1 GeV)
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ERL RD for Electron-Ion Colliders, Electron
Cooling of Ion Beams and Bright Light Sources
Accelerator RD Issues Creation, transport and
acceleration of extremely low-emittance,
high-current beams up and down the energy cycle
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Energy Recovering Linacs

• Examples in this category include light sources,
  free electron lasers, electron coolers and
  electron ion colliders.
• These accelerators are characterized by large
  beam currents that are simultaneously accelerated
  and decelerated in the same cavities, so there is
  little net transfer of RF power between the
  sources and the cavities. These high currents
  still generate large amounts of HOM power that
  will need to be extracted in order to prevent
  beam instabilities and small fluctuations in the
  beam properties can cause a large random beam
  loading that will have to be controlled.
• The critical technical issues are
• Cavity designs for high current
• HOM mitigation and extraction
• RF control of random beam loading,
  microphonics
• Mitigation and control of beam lines
• Beam instabilities

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Accelerated Vacuum Radiation for JLab FEL
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Proposed Experiments at JLab and SLAC by
Collaboration(CWM/ODU/UVA/JLab/SLAC)
From Pisin Chen, SLAC
Temperature/acceleration relationship
New FEL can get a2x1024 m/s for an
electron Equivalent to a temp of 104K
LCLS
http//www.slac.stanford.edu/slac/media-info/20000
605/chen.html
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Accelerated Vacuum Radiation for JLab FEL (contd)
Possible Graduate Research Laboratory
Astrophysics!
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Ultrashort Bursts of Energy Motivation
Scientific Possibilities with Femto- and
Atto-second Electron Pulses, X-rays, g-rays and
FELS
10 18 seconds lt t lt 10 15 seconds


Novel interactions of ultrashort pulses with
particles/atoms/molecules/bulk matter at the
Quantum Limit of Rapidity
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Incoherent vs. Coherent Ionization
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Laser Femto-slicing of Electron Beams
Reference Generation of Femtosecond Pulses of
Synchrotron Radiation R. Schoenlein, S.
Chattopadhyay, H.H.W. Chong, T.E. Glover, P.A.
Heimann, C.V. Shank, A.A. Zholents, M.S.
Zolotorev Science, Vol. 287, No. 5461, March 24,
2000, p. 2237.
Unique experiment in the world
Optical Manipulation of Beams
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Outlook

• Understanding Quantum Optics driven by
  accelerated charges will be critical in these
  studies. ? Coherence and degeneracy of an
  attosecond light pulse in the THz!!
• Opportunities in Ultrafast Science, Nonlinear
  Dynamics, SCRF, THz Laboratory Astrophysics look
  exciting!!

only a few photons in coherence volume