Suite of three protein crystallography beamlines with single superconducting bend magnet as the source.
At the Advanced Light Source, three protein crystallography beamlines have been built that use as a source one of the three 6 T single-pole superconducting bending magnets (superbends) that were recently installed in the ring. The use of such single-pole superconducting bend magnets enables the development of a hard X-ray program on a relatively low-energy 1.9 GeV ring without taking up insertion-device straight sections. The source is of relatively low power but, owing to the small electron beam emittance, it has high brightness. X-ray optics are required to preserve the brightness and to match the illumination requirements for protein crystallography. This was achieved by means of a collimating premirror bent to a plane parabola, a double-crystal monochromator followed by a toroidal mirror that focuses in the horizontal direction with a 2:1 demagnification. This optical arrangement partially balances aberrations from the collimating and toroidal mirrors such that a tight focused spot size is achieved. The optical properties of the beamline are an excellent match to those required by the small protein crystals that are typically measured. The design and performance of these new beamlines are described.
MacDowell
Alastair A
AA
Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. aamacdowell@lbl.gov
Celestre
Rich S
RS
Howells
Malcolm
M
McKinney
Wayne
W
Krupnick
James
J
Cambie
Daniella
D
Domning
Edward E
EE
Duarte
Robert M
RM
Kelez
Nicholas
N
Plate
David W
DW
Cork
Carl W
CW
Earnest
Thomas N
TN
Dickert
Jeffery
J
Meigs
George
G
Ralston
Corie
C
Holton
James M
JM
Alber
Tom
T
Berger
James M
JM
Agard
David A
DA
Padmore
Howard A
HA
D018360:Crystallography, X-Ray / Q000295:instrumentation* / Q000379:methods*; D004553:Electric Conductivity; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008280:Magnetics / Q000295:instrumentation*; D011487:Protein Conformation; D011506:Proteins / Q000032:analysis* / Q000737:chemistry*; D017356:Synchrotrons; D018511:Systems Integration
D011506:Proteins