1. Scintillator HCAL: LOI issues
Felix Sefkow
ILD meeting
Seoul, Korea, 17. February 2009

2. Felix Sefkow Seoul, 16. February 2009
AHCAL
Felix Sefkow Seoul, 16. February 2009

3. Cost drivers, optimization
The main cost driving parameters are
The choice of the absorber material
The overall depth in terms of interaction lengths L
The longitudinal sampling s
The transverse segmentation d
The dependence of PFLOW performance on geometrical parameters has been comprehensively studied with Pandora for stainless steel
Near plateau region for L and d
Shallow dependence for s, seems to be sensitive to algorithm
Other materials:
brass mechanically less attractive, but back-up if µ too large
Tungsten: probably too costly; study just started, not for LOI
AHCAL
Felix Sefkow Seoul, 16. February 2009

4. Felix Sefkow Seoul, 16. February 2009
Optimization studies
AHCAL
Felix Sefkow Seoul, 16. February 2009

5. Felix Sefkow Seoul, 16. February 2009
R&D status
CERN
FNAL
The first generation ‘physics prototype” is running in test beams since 2006, to be completed this summer
Robust and stable operation, low noise, no ageing (< 0.5 permille)
Test beam analysis
Done: calibration, e.m. linearity, hadronic response, resolution, longitudinal profiles  support Geant4 based Pandora studies
Still to come: shower radius, 2-particle separation, E+HCAL combined analysis, substructure and weighting  ~ 2011
AHCAL
Felix Sefkow Seoul, 16. February 2009

6. (Birks law, pulse shape)
Test beam results
Essential:
Corrections to data
(temperature)
and Monte Carlo
(Birks law, pulse shape) π e
Ongoing analysis
A.Kaplan
Ongoing analysis
B.Lutz
AHCAL
Felix Sefkow Seoul, 16. February 2009

7. Felix Sefkow Seoul, 16. February 2009
R&D plans
2nd generation technical prototype underway
Embedded electronics
New ASICs: power pulsing, auto-trigger, zero-suppr. + digit.
Several options for scint-SiPM/MPPC-electronic coupling
New operational challenges
Timeline
PCB with tiles in March
Full layer and e.m. tower end 2009
HCAL 2011
L.Raux 2m
M.Reinecke
K.Gadow
AHCAL
Felix Sefkow Seoul, 16. February 2009

8. Felix Sefkow Seoul, 16. February 2009
Dead zones
Detailed implementation of sector boundaries in Mokka
Too conservative with respect to most recent active layer design
Replace aluminum frame by srews, 99% filling possible
Variations simulated, not too critical for PFLOW
Space for external electronics at barrel end face, between cable routes; can be made small, like ECAL
M.Reinecke
AHCAL
Felix Sefkow Seoul, 16. February 2009

9. Felix Sefkow Seoul, 16. February 2009
Background
Radiation damage:
Only issue: neutrons in the very inner region of the end caps
Radiation hardness subject of photo-sensor R&D (sLHC)
Scintillator not affected
Occupancy:
Relevant for DAQ front end buffer depth and band width
Would like to study gamma gamma and mini-jet events
I recall from 2004 studies: 1 event every 3rd BX with 6 GeV in main calorimeters
AHCAL
Felix Sefkow Seoul, 16. February 2009

10. Felix Sefkow Seoul, 16. February 2009
Calibration
Temperature-induced variations of photo-sensor:
Monitor: single ph.e peaks
Control: compensate by adapting voltage
Possible long-term variations of light yield
Scintillator ageing, optical coupling instability,..?
Use track segments in hadron showers
F.Simon
AHCAL
Felix Sefkow Seoul, 16. February 2009

11. Felix Sefkow Seoul, 16. February 2009
ILD simulation study
Use algorithm developed on test beam data
1000 hits / cell
 GeV
 GeV
1000 hits / m2
 GeV
High granularity: insensitive to statistical cell to cell variation
Need clever averages to control trends
And good design, optical stability
S.Lu, F.Simon
9 tracks
AHCAL
Felix Sefkow Seoul, 16. February 2009

12. Felix Sefkow Seoul, 16. February 2009
Support structure
K.Kschioneck
K.Gadow
Following FEM calculations, support should be at 4 and 8 o’clock
HCAL stands on the tip!
AHCAL
Felix Sefkow Seoul, 16. February 2009

13. This and following slides:
Integration, step 1
This and following slides:
K.Gadow
AHCAL
Felix Sefkow Seoul, 16. February 2009

14. Felix Sefkow Seoul, 16. February 2009
Integration, step 2
AHCAL
Felix Sefkow Seoul, 16. February 2009

15. Felix Sefkow Seoul, 16. February 2009
Integration, step 3
AHCAL
Felix Sefkow Seoul, 16. February 2009

16. Felix Sefkow Seoul, 16. February 2009
Integration, step 4
AHCAL
Felix Sefkow Seoul, 16. February 2009

17. Felix Sefkow Seoul, 16. February 2009
ECAL integration, step 1
AHCAL
Felix Sefkow Seoul, 16. February 2009

18. Felix Sefkow Seoul, 16. February 2009
ECAL integration, step 2
AHCAL
Felix Sefkow Seoul, 16. February 2009

19. Felix Sefkow Seoul, 16. February 2009
Conclusion
Answers to IDAG questions reasonably well prepared
Well motivated design, clear R&D path
Status of LOI draft: still a lot to do
AHCAL
Felix Sefkow Seoul, 16. February 2009