View
231
Download
0
Category
Preview:
Citation preview
msantana@slac.stanford.edumsantana@slac.stanford.eduBLM review
Mario Santana Leitner
OUTLOOK ON FLUKA SIMULATIONS FOR UDULATOR DAMAGE AND BLM
RESPONSE
Mario Santana Leitner, Alberto Fassò
and Joachim VollaireRadiation Protection Department
Stanford Linear Accelerator Center
LCLS Beam Loss Monitor Preliminary Design ReviewSLAC, January 24, 2008
msantana@slac.stanford.edumsantana@slac.stanford.eduBLM review
Mario Santana Leitner- 2 / 18 -
Outline
Characterization of demagnetization under radiation
fields
Radiation showers along the undulator
Beam loss monitor response and correlation to losses in
the undulator
msantana@slac.stanford.edumsantana@slac.stanford.eduBLM review
Mario Santana Leitner
FLUKA geometrySLAC Experiment
(9 Nd-Fe-B Samples, 13.7-GeV electron)
Characterization of the demagnetizationLCLS Permanent Magnet Damage Study; experiment T493
Experiment spokesman: by
Heinz-Dieter Nuhn
msantana@slac.stanford.edumsantana@slac.stanford.eduBLM review
Mario Santana Leitner
1. Dose calculated and demagnetization measured are for the whole sample2. Difference between forward and side samples
Characterization of the demagnetizationMeasured Damage Not Proportional to Dose
msantana@slac.stanford.edumsantana@slac.stanford.eduBLM review
Mario Santana Leitner
Sample 1 Neutron fluence in all samples
Characterization of the demagnetizationDose Fraction and Neutrons
msantana@slac.stanford.edumsantana@slac.stanford.eduBLM review
Mario Santana Leitner
Characterization of the demagnetizationMapping of 2-D Neutron Fluence in Samples
msantana@slac.stanford.edumsantana@slac.stanford.eduBLM review
Mario Santana Leitner
Characterization of the demagnetizationMapping of Measurement of 2-D Demagnetization
Demagnetization
measurements analyzed
by Heinz-Dieter Nuhn
msantana@slac.stanford.edumsantana@slac.stanford.eduBLM review
Mario Santana Leitner
Characterization of the demagnetizationNew FLUKA simulations to match demagnetization grid
The geometry of the magnets has been re-written to match the
detector scoring with the virtual sub-regions
- 800 detectors for the fluence
- Region bin-size 2mm x 2mm
Simulations to be sent now
Analysis of the results requires some time
msantana@slac.stanford.edumsantana@slac.stanford.eduBLM review
Mario Santana Leitner
LCLS model including detailed
description of the segments, dumps,
magnets, magnetic fields, etc.
BLM array just introduced.
Radiation showers along the undulatorFLUKA model of LCLS
msantana@slac.stanford.edumsantana@slac.stanford.eduBLM review
Mario Santana Leitner
Radiation showers along the undulatorMagnetic field test. Electron transport.
30 micron
displacement in X or
Y plane.
Further analysis
ongoing…
msantana@slac.stanford.edumsantana@slac.stanford.eduBLM review
Mario Santana Leitner
BLM response simulation and
correlation to losses in the undulator
BLM coarse geometric implementation done.- Array of BLM’s at 40 cm from following segment- thin W radiator in the front. What should be the thickness?- What is the thickness of the aluminum wall in the inner
surfaces?
FLUKA scoring subroutines to be written.
Other FLUKA options to be examined.
Since
Biasing destroys correlations: therefore for this option it is necessary to run FLUKA in analog mode.
msantana@slac.stanford.edumsantana@slac.stanford.eduBLM review
Mario Santana Leitner
FLUKA features for BLM simulationsCommand DETECT
We call an "event" the energy deposited in a user-defined set of one or more DETECTOR REGIONS by one primary particle and by its secondaries.
We call a "signal" the energy deposited in a user-defined set of one or more TRIGGER REGIONS by the same primary particle and secondaries.
Output: a distribution of energy deposited per event in the DETECTOR REGIONS in coincidence with a signal larger than a pre-defined cut-off
Possible application: to find correlations between dose in BLM and dose in a set of magnets
Since
Biasing destroys correlations: therefore for this option it is necessary to run FLUKA in analog mode.
msantana@slac.stanford.edumsantana@slac.stanford.eduBLM review
Mario Santana Leitner
QUENCHING: FLUKA can calculate energy deposition in scintillators corrected for quenching, applying the Birks law.
This can allow to predict the correct BLM response in a mixed radiation field of photons, neutrons and other particles
OPTICAL PHOTONS: FLUKA can also produce and transport scintillation light if the user provides the wavelength.
FLUKA features for BLM simulationsQuenching and Optical Photons
Recommended