SPEAR Accelerator Restarts Operations
By Eduardo Guerra
and Jeff Corbett
SSRL’s SPEAR3 facility has restarted
operations after completing its restart validation process and receiving
approval to resume operations by the SLAC Director in consultation with
“The safe and smooth restart of SPEAR
was possible due to the extraordinary effort by SSRL staff and the
tremendous support SSRL received from the other SLAC divisions
throughout this process and the efforts by all the staff to implement
and follow safety protocols,” said SSRL Associate Director Keith
SSRL department heads developed a
Facility Restart Plan over the winter break to present to Director
Jonathan Dorfan of SLAC for formal approval to operate SPEAR3. A review
team appointed by the SLAC Director carried out a validation process of
the restart plan between January 3 and January 13. The validation team’s
report was positive, and on January 14, Ray Orbach, Director of the DOE
Office of Science, concurred with Dorfan’s recommendation that SSRL
Following written authorization from
Dorfan, the SSRL Accelerator Systems Department received permission from
Hodgson to turn on SPEAR3 on January 18. The accelerator startup process
proceeded smoothly. After commissioning the 100 MeV LINAC, transport
line and 3 GeV booster synchrotron, 10mA was stored in SPEAR3 on January
23 at 6 pm.
Interlock and electronic calibration
checks ensued and the circulating current was increased to the nominal
operating value of 100mA. Measurements of electron beam position and
storage ring optics indicated the beam conditions were precisely the
same as for the previous phase of operation. At present, the photon beam
line check-out procedures are underway and the vacuum chamber is
processing at a record pace.
After completing the pre-start
requirements identified during the validation review, Dorfan gave
written approval on January 27 to start the process of bringing the beam
lines back on line for the users. This began with the execution of the
beam line authorization process in which Radiation Physics and SSRL
staff ensure the proper placement of radiation shielding components. The
first beam line was then certified and by Friday, four beam lines were
opened for alignment and initial radiation surveys.
During the coming week to 10 days,
the remainder of the beam lines will be opened and the detailed
radiation surveys will be performed. It is expected that beam will
become available to users on some beam lines or before February 7.
Normal full beam line operations are expected within two weeks
SPEAR3 and the B Factory have been
shut down since October, when a serious electrical accident led Dorfan
to order the immediate suspension of operations.
Since the accident, SLAC has been
rigorously scrutinizing safety procedures and safeguards to ensure that
the accelerator facilities will be operated at the highest levels of
safety. Dorfan was determined that each major facility complete a
specific safety validation review to satisfy him and the DOE that there
was a safe path forward.
“The restart of SPEAR3 operations should not in any way divert our
ongoing attention from the strongest commitment to safety,” Dorfan said.
“Our long-held commitment is that operational expediency can never