Post on 28-Mar-2015
transcript
J. Feikes; Status of MLS
European Synchrotron Light Source XVI.
Commissioning of the Metrology Light Source
in Berlin AdlershofJ. Feikes for the BESSY&PTB-Commissioning Team
• MLS = Light Source owned by the PTB (??)
optimized as a VUV to THz Source
• built and operated by former BESSY now HZB
• A dedicated design to include THz generation (Godes Talk)
J. Feikes; Status of MLS
European Synchrotron Light Source XVI.
Metrology Light Source
Some MLS parameters
• 48m circumference • Double bend achromat lattice• 200MeV - 600MeV operating energy• 1 electron up to 200mA current • 105 MeV injection Microtron
J. Feikes; Status of MLS
European Synchrotron Light Source XVI.
• July 13, 2007 first accumulated beam 1mA
• Aug 14, 2007 first beam ramped to 630 MeV
• Aug 25, 2007 accumulation up to 10 mA by slow injection (every 6 s )
• Sep/Oct 2007 current limit around 12 mA --> Ions
• April 1, 2008 start of user operation
• May 5, 2008 design current of 200 mA reached
• Nov 14, 2008 undulator U180 succesfully commissioned
MLS Commissioning Milestones
J. Feikes; Status of MLS
European Synchrotron Light Source XVI.
Accumulation up to 10 mA by slow injection (6 s )
current
be
am
cu
rre
nt
/ m
A
current loss per shot
J. Feikes; Status of MLS
European Synchrotron Light Source XVI.
Injection problems caused by ions
• current increment cause poor lifetime at I >few mA
• reason: beam blow up due to ions. Beam fills aperture completely solutions:
ion clearing (-300V at 8 BPMs at ends of straights)
beam shaking at transversal Tune
beam scrubbing -> next slides
J. Feikes; Status of MLS
European Synchrotron Light Source XVI.
Cycling with minor beam loss
1. faster current refill 2. radiation protection - no beam loss@630 MeV 3. simplifies automated scrubbing
J. Feikes; Status of MLS
European Synchrotron Light Source XVI.
Automated beam scrubbing tool: “Operation Master“automated operator („state machine“)
J. Feikes; Status of MLS
European Synchrotron Light Source XVI.
Operation Master –flow chart
J. Feikes; Status of MLS
European Synchrotron Light Source XVI.
Beam Scrubbing – Operation Master (detail)
• highly complex • minimizing operator errors• develops iteratively by practical use• good experience with automated operation
correct ramp tables loaded ?
J. Feikes; Status of MLS
European Synchrotron Light Source XVI.
Automated Beam Scrubbing at MLS
J. Feikes; Status of MLS
European Synchrotron Light Source XVI.
Beam Scrubbing – efficiency still improving
J. Feikes; Status of MLS
European Synchrotron Light Source XVI.
MLS – typical user operation conditions
• typical initial currents of 120 – 140 mA at 8 hrs LT
• typical Run time 6 hrs
• Injection cycle: Ramp-Down-Refill-Ramp-Up ~ 15 min