Valproic acid in SMA Brunhilde Wirth Institute of Human Genetics University of Cologne, Germany.
PRESORT OF THE DATA OF THE COLOGNE TEST EXPERIMENT
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Transcript of PRESORT OF THE DATA OF THE COLOGNE TEST EXPERIMENT
PRESORT OF THE DATA OF THE
COLOGNE TEST EXPERIMENT
● Quality and integrity of data● Detector numbering and positions ● Calibrations and gain stability● Reactions channels identification
The experiment
Main characteristics of the setup
BEAM 48Ti 100 MeV
TARGET 48Ti + 2H 220 μg/cm2
Si detector
thickness 300 μm
segmentation 32 rings, 64 sectors
Absorber thickness 16 μm (Al)
AGATA symmetric triple-cluster
What to check
● Quality and integrity of data
– Sector energies mostly missing
– Some segments are in short circuit and other are
missing● Detector numbering and positions● Calibrations and gain stability● Reactions channels as expected ?
Quality and integrity of data
validation
• Silicon detector fires with almost all his sectors and rings every event
• The time of a lot of channels is in overflow
We can ask for a validation with an autocoincidence
After validation the multiplicity of sectors and rings is (1, 1) as expected for the reaction
TDC of silicon detector
Quality and integrity of data
real gate validation
TDC of silicon detectorTDC of germanium detector
Quality and integrity of data
With gate on sector energy
Without gate on sector energy
Quality and integrity of data
3 segments in short circuit
2 segments in short circuit
Some segments missing/low statistics
What to check
● Quality and integrity of data● Detector numbering and positions
– Ring numbering
– Sector numbering
– Silicon detector position● Calibrations and gain stability● Reactions channels as expected?
Geometry – ring numbering
Counts on the rings ~ ring solid angle
Tape number 19: alpha source
● Inverse numbering of
the rings● The distance between
the source and the silicon
detector is 34 mm
(what about the target?)
Geometry – sector numbering
)cos(1
1 2
cmlab
EE
Depends on the angle of the firing sector
49Ti: 1381 keV
48Ti: 983 keV
The Doppler correction depends also on:
• the mass of the scatterer nucleus
• the reaction mechanism
Geometry – sector numbering
x
y
12.3 ± 0.5 deg
08
16
24
3240
48
56
63
FRONT view (from the target)
Center of the cluster in the yz plane
Ge detectors
Eγ – sector # Eγ – sector #
Geometry – silicon detector position
BEAM IS OFF AXISDISTANCE: 2.67 ± 0.01 mmDIRECTION: 100.4 ± 0.1 deg (~ direction of sector 19)
Center of silicon detector
Beam position
SI DETECTOR IS NOT PERPENDICULAR TO BEAMANGLE (θ): 4.50 ± 0.02 degDIRECTION (φ): 100.4 ± 0.1 deg (~ direction of sector 19)
OR
beam
Si det
Target
Rint = 16.5 mmd = 2.7 mmθ = 4.5 deg
ring # – sector # ring # – sector #
What to check
● Quality and integrity of data● Detector numbering and positions● Calibrations and gain stability
– DGF stability● Reactions channels as expected?
Electronics stability
DGF gain stability: ● rough calibration using 60Co sources● fine recalibration using
511 keV peak during run
with beam
What to check
● Quality and integrity of data● Calibrations and gain stability● Detector numbering and positions● Reactions channels as expected?
– (d,p) 49Ti
– (d,d’) and (d,pn) 48Ti
– Other reaction channels ?
Channel identification: gamma spectrum
Gammas from 49Ti
Channel identification: (d,p) through direct reaction
Q value of (d,p) reaction: 5.92 MeV
Excitation energy: 6.2 MeV
keV
keV
Channel identification: (d,p) through fusion evaporation
PACE calculation: proton spectrum in CM
PACE Coulomb barrier: 3.95 MeV
Proton with 4.5 MeV in CM
4.53.5
5.56.5
Channel identification: gamma spectrum
Gammas from 49Ti and 48Ti
Channel identification: (d,d') direct and (d, pn) fusion
evaporation
(d,d’) direct (d,pn) fusion-evaporation (?)
Gate on gamma energy 983 keV
Channel identification: other reaction channels ?
Gate on gamma energy 983 keV
Protons and deuterons can not deposit so much energy
Is it noise? Why only at small angles?
48Ti
2H
Channel identification: other reaction channels ?
16O
12C
Channel identification: other reaction channels ?
12C 14N 16O
Channel identification: other reaction channels ?
Absorber thickness: 16 µm
ABSORBER NUCLEUS
6 µm 48Ti
10 µm 27Al
16 µm 16O
18 µm 14N
21 µm 12C
logbook
Channel identification: other reaction channels ?
Channel identification: other reaction channels ?
Low energy
High energy?
• Time correlation between high and low energy events in si-detector
• Concentration of impurities increases with time
• High concentration of low energy events in tape 15 and 16 not understood
Channel identification: other reaction channels ?
new target (chamber opened)
changed Si-HV and threshold
Overflow is expected here but there is not!
Channel identification: other reaction channels ?
Overflow is expected here but there is not!
This region has the right:• deflection angles• gamma spectrum• statistical dependence on time• Doppler correction
Channel identification: other reaction channels ?
Overflow is expected here but there is not!
This region has the right:• deflection angles• gamma spectrum• statistical dependence on time• Doppler correction
Channel identification: other reaction channels ?
This can mean that electronics did not work the way we expected
Channel identification: other coulex reactions
This region has the right:• deflection angles• gamma spectrum• statistical dependence on time• Doppler correction
This can mean that electronics did not work the way we expected
Channel identification: statistics and selection
mechanism Gamma energy
Energy in silicon detector
counts
(d,p) direct 1381 keV
750k(d,p) fus-evap 1381 keV
(d,d’) direct 983 keV < 30k
(d,pn) fus-evap 983 keV < 15k
(HI, HI’) coulex 983 keV E > 8 MeV 80k
(HI, HI’) coulex 983 keV 2 < E < 8 MeV ~ 100k
(HI, HI’) coulex 983 keV 0.3 < E < 2 MeV 140k
mixed
mixed
220k counts
Conclusion: what to analyse ?
16O
12C
Experiment designed for d(47Ti, 48Ti)p direct
reaction
Beam was 48Ti No direct reaction
on target
We still have a nice direct reaction on contaminant(s) !
BUT
• Smaller statistics• Use of background
Quality and integrity of data
Quality and integrity of dataData structure
Sector #, Energy, Time Sector #, Energy, Time…Ring #, Energy, Time Ring #, Energy, Time…
Germanium #, Energy, Time…
Segment #, Trace, Energy….
Silicon detector
Germanium detector
VME modules
DGF modules