By Tom Mead
The second three-day workshop planning the capabilities of
the ORION Center for Advanced Accelerator and Beam Physics Research
concluded on February 20 at SLAC.
In keeping with the international mix of the 95 workshop
registrants, ORION, like SSRL, will be a university and national
laboratory collaboration. It will be a center of, and dedicated user
facility for, experimental research in plasma and laser acceleration of
particles, beam-plasma physics, ultra-short pulse electron and radiation
sources, and potentially, laboratory astrophysics.
As Tom Katsouleas, USC Professor of Engineering and
co-director of the nascent ORION Center, noted, "It is at the highest
energies that we see Nature on the smallest of scales. The realities
within those smallest scales are the foundation upon which the origin of
our Universe, stable matter, galaxies, and ultimately life, depends. The
development of entirely new approaches to reaching such high energies is,
at its heart, the true motivation behind ORION."
This graphic shows how the unique interrelationships
of the ORION Center and its state-of-the-art facilities (outer circle)
converge to enable advances in basic physics (mid-level), ultimately
leading to the energy frontier. (Graphic
by Tom Katsouleas (USC) and ScientificArts Media)
"But ORION is about more than developing future
accelerators. It turns out that the short bunches, lasers and plasmas
involved in these new approaches exhibit in themselves rich new physical
behavior that ORION will unveil along the journey toward the high energy
Research will begin, at inception of the Center, with
experiments at the Final Focus Test Beam (FFTB), an extensively
instrumented beamline at the end of the SLAC main linac that can deliver
30 GeV electron and positron beams. The FFTB will be available for two or
three more years.
In the longer-term, these experimental activities will be
concentrated at the ORION facility, funded through the Center. The ORION
Facility will be based on the Next Linear Collider Test Accelerator (NLCTA),
operating at SLAC, which is capable of providing beams from 50 to 350 MeV
in energy. For ORION, the NLCTA will be augmented with a new
high-brightness photoinjector source, two experimental halls, extraction
beam lines, a user laser room and a data acquisition area.
The Center is being designed to provide for the research
needs of the users. Thus, this workshop was used to explore the range of
experiments envisioned by potential users and to review the types of beams
available as well as the desired beam parameters. The workshop was an
opportunity for the research community to provide input on the facility’s
test beams, layout, shared diagnostic equipment, simulation and computing
capabilities, and user support infrastructure.
"This workshop," said Katsouleas, "was extremely useful
for assuring that ORION builds in the flexibility to serve as many user
experiments as possible. I think the science on ORION’s plate is excellent
and the enthusiasm of the participants at the workshop reflected this."
The ORION project arose because particle physics addresses
fundamental questions about the origin of mass and the observed symmetries
in nature. Historically, these types of questions have been answered at
the highest energies—the energy frontier—and science discoveries have
emerged hand-in-hand with the exponential growth of machine energies.
Thus, advanced accelerator research is essential to the future of particle
There are advanced accelerator concepts based on plasmas,
lasers, high-gradient radio frequency structures and novel technologies.
They hold the significant promise of continuing the growth in available
energy and, through it, profound new insights into nature.
Results from the workshop will help determine the
facility’s design, as well as help SLAC management plan for future on-site
user needs. Construction is expected to start in October 2003, and the
first beam for experiments is planned for 2005. The primary developers of
the facility are the University of Southern California, the University of
California at Los Angeles, Stanford University and SLAC.