Group-leader: Pat Colestock LANL (firstname.lastname@example.org)
Co-Group-Leader: Ralph Fiorito UMd (email@example.com)
In this working group study,
we will review three issues of advanced accelerators:
beam diagnostics, beam source characterization, and
control, synchronization and monitoring.
After reviewing the state of
the art in beam diagnostic techniques, this group will
confront the challenge of improving the the 6D phase
space diagnostic resolution by a factor of ten, for
low, medium, and high energy beams. The WG will also
identify the ultimate limit in measuring and controlling
the synchronization of two events in space, time and
frequency. (can we measure beam properties with sub-micron,
sub-10 fs accuracy?)
Depending on the beam’s
properties one would like to study (charge/current,
spatial profile, divergence, emittance, temporal length,
temporal shape, energy, energy spread, etc.) one would
use different diagnostics. Diagnostic techniques can
be either field based or radiation based. Few diagnostics
can provide the beam’s phase space properties
directly. Most will require some data processing, which
could be subject to human interpretation. For plasma
advanced accelerators, one would also want to know the
characteristics of the plasma through which the beams
Beam characterization at the
sources is the single most important step in understanding
the mechanisms of beam quality degradation. Beam’s
quality varies significantly from one source to another
and depends intricately on sources’ operating
conditions. We will review standard emittance measurement
techniques and analyze their capabilities and limitations.
Another important feature of low-energy beams is space-charged
induced effects such as transverse plasma oscillation,
a potential source of confusion for emittance measurement.
Longitudinal space charge effects such as virtual cathode
formation and longitudinal beam breakup have been experimentally
observed. Finally, halo formation is another topic of
great interest (or concern) as halos can lead to significant
Control, synchronization and
monitoring are crucial if the beams are to be used in
conjunction with the rest of the world. RF control and
synchronization are probably perfected by now, and so
are laser timing control and synchronization. Nevertheless,
control and synchronization of the RF and laser together
have not been that easy. Adding the beams to this mix
only compounds the problems. We will review the state
of the art of timing control and synchronization. We
will also study beam monitoring at low, medium and high
energy, with an emphasis on stray particle management.
We will tailor the invited talks
to match the above categories. We will accept contributed
papers in the above areas as well as other related topics.
We will ask participants of this working group to appoint
a “spokesperson” for each of the above categories.
The spokespersons will document all information relevant
to their respective areas. At the end we will review
the information with the spokespersons and ask for their
assessments. At the close-out, the spokespersons will
present the assessments of their respective issues to
the working group and open the floor for discussion.
Finally, the chairperson and the deputy will summarize
the working group findings.