Agenda for October 31, 2002

Christoph\-\--results of machine tests with respect to coupling/vertical
dispersion correction using individual skew quads

Malcolm\-\--Scattering and the "bow tie" effect.

David\-\--report from Pascal Ellaume conversation

Phil\-\--report from visit to Trieste

Alan \-\-- Action Item review

MINUTES

The Physics group and the ID folks confirmed that they would be prepared
for the W11 review on November 19. The "second" week in January ( the
week beginning January 12 !) was confirmed as suitable for the full
project review. Alan will communicate this to Kem Robinson.

It was pointed out that the W11 review needed to include a presentation
of the impact on the Protein Crystallography program. Next week Ross and
Steve will update the W11 industrial progress in preparation for the
review. The protein crystallography situation should also be discussed
to firm up the agenda and speakers at the review.

Christoph reported on the progress of the minimization of the vertical
emittance, correction of the spurious vertical dispersion and control of
the vertical beamsize. To control those quantities 18 individual skew
quadrupoles are used. The coupling distribution is measured precisely by
analyzing orbit response matrizes. There are many reasons why these
efforts are important for the femtosecond project. The main reason is
that the vertical dispersion bump to achieve the necessary separation
creates a significant amount of vertical emittance. So to keep the
overall emittance at the level it is right now and therefore minimize
the impact on other users and improve the separation for the femtosecond
line, the baseline emittance ratio has to be improved over what we
routinely have achieved in the past Goal values (compare Sasha\'s note)
are emittance ratios of 0.5-1.0%. Using the above mentioned tunes we
have achieved emittance ratios of about 0.5% in a very systematic and
therefore reproducible way. In addition we have tested a method to
control the vertical beamsize by using a vertical dispersion wave. This
will be important to keep the beamsize constant when the field of the
superconducting undulator is changed.

Malcolm deferred his optics progress report to next week. He handed out
a paper setting down scattering theory and recommended that it be read
in preparation for next weeks presentation. He then went on to explain
his interpretation of the "bow tie" images seen in data from beamline
7.3.3. He proposed that the effect was a result of scattering in
conjunction with the coma aberration of the toroidal mirror. That is,
the image created as a result of the scattering is as if the object were
stretched out. Stretched out objects are known to create a bow tie image
after a sagitally focussing mirror. The effect will not be an issue for
our application as this scattered part of the image is offset from the
central beam and can be masked out.

David gave a report on his conversation with Pascal Ellaume from ESRF.
Pascal is enthusiastic about the use of cryocoolers and is serious about
getting into the superconducting ID business. He is planning on a
program at ESRF with the goal of having a usable device four or five
years from now when he believes these devices will outperform in-vacuum
ID's. He is thinking of building one device in-house and one with ACCEL,
he wants expertise to be developed in-house. Bob commented that this
seemed to be a philosophy change with regard to how ESRF does business.
Ross and Steve responded that this was consistent with their approach to
conventional ID construction. Engineering designs were developed by ESRF
staff and the fabrications were carried out with industrial contracts,
They drew a comparison to our methods which are similar except at LBNL
we have used our own shops for the major assembly work rather than
industry. They said that ESRF had been motivated to transfer technology
to industry so that other institutions could be referred to industry as
a resource for the devices rather than having to rely on assistance from
ESRF. Following up on an action item Ross said that he had sent Email to
ACCEL asking for an interest statement and for a possible visit . It was
commented that ESRF has leverage with ACCEL as they are potentially a
big customer and can be the conduit for significant business.

Phil reported on his visit to Trieste. They have accepted the
superconducting wiggler from Novosibrsk. It completed 3.6 Tesla field
and quenching tests. This device has cryocoolers but requires liquid
helium for cryogenic performance to meet operational parameters. It has
a 20K cold bore vacuum vessel. It was commented that there had been a
lot of problems with the cryogenic design of this wiggler. It was
suggested that we talk to people from BESSY 2 who have additional
experience with a similar device from Novosibirsk. Ross commented that
they were not pushing the state of the art like we must to meet our
needs. Ben pointed out that we want to tap into the knowledge of others
in this field. The group was in agreement to this but had concerns that
experience indicated that ACCEL, who must operate in a commercial
competitive environment, were reluctant to share information. As we are
planning on a design that has a 4K vacuum wall temperature it was
suggested that contact be made with people at MAX lab. They have data on
the heat load that may be expected under similar conditions to what we
must design to.

Ben raised the question of the reuse of the support and drive system
from W16 for W11. He suggested that it may be possible to do magnetic
characterization on W11 without the need for the support and drive from
W16, this would reduce the downtime required for the switch. Howard
reminded us that it would be necessary to have a structure capable of
holding and moving the magnetic structure,, it would need to move from
the open to the closed position and would need to handle the large
magnetic forces. Subsequent to the meeting Steve reported to Alan that
he estimated the time to remove W16, disassemble, install new backing
beams and a new vacuum chamber, and reinstall, to be seven weeks.

Alan reviewed all current Action Items for acceptance by the designated
person responsible, and for status.

ACTION ITEMS

Presentation by Rob and Phil of the beamline status on November 7.

Check options for W16 cost recovery with Jeff Weiner\-\-\--Alan

Get written approval for the installation of W11 from BCSB
management\-\--Howard?

Prepare formal request for UCDRD funds for wiggler\-\--Bob

determine the status of other sc undulator projects - particularly at

ACCEL, see if they would be interested to bid on our device, or if a

collaboration with another facility would be worthwhile\--Ross/Steve

establish criteria for evaluating field roll-off specs for wiggler and

undulator-Christoph

get list of Robinson Review requirements and set date for full project

review\--Bob/Alan

check status of budget and start date with DOE-Bob