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SSRLUO Minutes
Welcome/Introductions
Attendees: Juana Acrivos, Zaven Altounian, Joy Andrews, Linda Brinen,
Michael Brzustowicz, Lisa Downward, Lisa Dunn, Jesse Guzman, Britt Hedman,
Bob Hettel, Cathy Knotts, Piero Pianetta, Bill Schlotter, Jo Stöhr,
Glenn Waychunas.
Safety Update
Ian Evans gave a presentation on safety, including suggestions for both work
and home. In reply to a question about the machine shop at SSRL, users were
discouraged from using this shop without specific authorization. They can,
however, contact SSRL staff or the Duty Operator to find out if someone can
help them to get parts machined. Users are encouraged to stay informed and
follow policies as they relate to safety and to ask if they have any questions.
Welcome/Introductions
SSRL Director's Update
SSRL Director Keith Hodgson reviewed recent organizational changes at SLAC,
which now has 2 main scientific programs: Photon Sciences (Keith Hodgson heads
this group) and Particle & Particle Astrophysics (Persis Drell heads this
group). Photon Sciences encompasses SSRL and ultrafast science which includes
the LCLS science program and a program to develop ultrafast scientific
instruments. Keith noted that the report from the DOE program review of SSRL
which was held in late January had been received; the report was overall very
positive and the panel made a few suggestions including the addition of a
separate scientific advisory committee, the need for more beam line support
staff, and further development of career paths for beam line scientists.
Keith also reported that SPEAR3 achieved a major milestone in June when 500mA
was reached for the first time; things are moving along smoothly and as
designed. Additional high current tests are planned for the remaining AP days
this run (July 18-19), including tests at BL6-2. Further reviews and approvals
are needed by Radiation Protection for 500mA operations in SPEAR and later to
deliver to beam lines. We anticipate periods of high current running sometime
next year.
Top-Off Injection
Bob Hettel summarized the status of SPEAR, including some diurnal changes,
movement and noise that has been noted. A medium orbit feedback system now
addresses the trestle movement which was distorting signal at 100mA. A group
(including Sean Brennan and Andrei Terebilo) has been assembled to investigate
stability issues. Users are encouraged to notify the program managers during
their 3 pm walk through whenever noise is experienced at the beam lines.
Bob stated the goal as low noise, thermally stable beam to users, working
towards the maximum potential which is 500mA. Higher brightness will be
advantageous for some experiments, but some beamlines would need to shut down
until they are fully upgraded for 500mA operations. We may try to question
users in the next call for beam time requests about their preference (or not)
for high current (beam time requests will be due in September for the run which
resumes Nov. 28th). It is difficult to predict now how this information will be
incorporated into the schedule for the next run until more information is
known; there will be internal meetings to help flush this out, and we hope to
be able to give users a better idea of the next run schedule before the Fall.
We want to be capable of reaching 500mA, and it would be easy to reduce
intensity if warranted. Results from early high current tests were promising,
and the various approvals are ongoing.
Questions were raised about shortening beam time allocations to accommodate
more users. Others noted that this was not very likely at SSRL given resources
limitations (experiment changeovers are still staff dependent). Also, longer
periods of beam time allow more difficult experiments or allow data to be
collected at lower concentrations. Group blocks of beam time may be
investigated, particularly among crystallographers, where groups running the
same type of experiment with the same equipment set up share beam time to
maximize available beam time (e.g., over a long weekend).
Bob discussed several fill scenarios for SPEAR3 at 500 mA as well as top-offs
at other labs. There are several reasons for pursuing this option, including
the potential improvement in the beam stability owing to the more constant
power loading on ring and BL optics as well as the performance boost associated
with top off. Without top off, there is some concern that 500mA power loading
on the BL optics will result in beam focus and monochromator tune drifts. The
issue will not likely be decided immediately (other labs took several years to
implement), and radiation protection approvals will need to be obtained for
both the ring and the individual beam lines. This topic will be discussed again
at the users' meeting with a brief presentation during the SSRL reports session
on Tuesday, October 18th and an opportunity to discuss in more depth at a
workshop on Wednesday, October 19th. SSRL beam line scientists and other users
with experience with top off are asked to be liaisons and encouraged to share
their experiences with the entire user community; this will help users get a
better idea of how and which types of experiments will be impacted with top
off.
SPEAR3- A Look into the Future (Including Pulsed Beam for Time Structure)
Jo Stohr presented several slides outlining the present status, vision for the
future, and goals for SSRL. Jo described 3 pillars of photon science at SLAC;
SPEAR3, LCLS, and Stanford Centers. This model is unique from other labs; the
overlap of faculty between Stanford and SLAC/SSRL and interplay of disciplines
represents a strong connection and asset. Jo briefly discussed opportunities to
use 50-100 ps systems (magnetism, surfaces, etc.). Currently electrons travel
in the ring in bunches or buckets. A pulsed beam would allow time resolved
studies. User input is requested to consider user interest for pulsed beam and
the impact on user experiments of this mode of operation; specifically, what
would be the desirable properties for a pulsed beam, how often, what types of
experiments would benefit, what is the impact on other types of experiments.
Jo also highlighted the unique role of X-rays over other technologies to better
understand structures and how they change with time - the future opportunities
are in the world of small and fast.
Piero Pianetta summarized the beam line upgrades and construction activities
planned over the summer shutdown which begins on August 1st, including upgrades
to BL10, BL9 and BL7. These beam lines will be available for users after
upgrades and commissioning are completed. For BL10-1, BL10-2 and BL9-3, this is
expected by mid December; BL9-1 and BL9-2 by January 2006. BL7-3 is expected to
be available for users by February 2006, with BL7-1 and 7-2 a bit later in
early 2006. A preliminary copy of 2006 user operations schedule, which is
expected to resume around November 28, 2005 and continue through July 31, 2006,
can be found at:
http://www-ssrl.slac.stanford.edu/schedules/06_run_preliminary.pdf
Update of User Activities and Activism
SSLRUOEC Chair Glenn Waychunas shared material prepared and presented by the
UEC chairs during the meetings in Washington in April.
3-3:30 pm SSRLUOEC Update
-
UEC chairs/vice chairs trip to DC in April; another meeting potentially in
the Fall
-
UEC chairs to meet at SSRL Oct. 17th
-
User activism (encourage visits to representatives; write letters)
http://www.dartmouth.edu/~ssrluo/
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3:30-4 pm 32nd Annual SSRL Users' Meeting
4:30-5 pm Outreach, Communications, User Administration (C. Knotts/L.
Dunn)
5-5:30 pm Walk-in Items
The meeting adjourned around 5:30 pm.
Cathy Knotts
SSRL Liaison to SSRL Users' Organization Executive Committee
