1. Roberto Calabrese Ferrara University and INFN
IFR status and outlook
Roberto Calabrese
Ferrara University and INFN
SuperB Workshop, Perugia June 16-19, 2009

2. Outline Introduction Progress since Orsay
Future activities towards TDR
Milestones
I will briefly present the general ideas of our experiment:
How it is possible to trap atoms using light force and magnetic field
Some words on Parity Non Conservation on Atoms (this is a field You know better than me…)
I will give then some details on the Fr element ; why it is suitable to perform PNC measurements
Then I will show the experimental setup (not yet complete!)

3. The IFR for Super B
The muon detector is build in the magnet flux return.
It will be composed by one hexagonal barrel and 2 endcaps like in Babar.
Possibility to reuse BaBar iron structure
Scintillation bars with WLS fiber to sustain rates O(100 Hz/cm2)

4. IFR requirements for Super B
Add iron to BaBar stack to improve m ID:
 8 detection layers should be enough
Keep longitudinal segmentation in front of
stack to retain KL ID capability.
The CDR layer configuration
Need to optimize:
Scintillation bars geometry
Number of active layers
Where and how much iron we need to add

5. The CDR style IFR
This technology was proposed also as replacement of the BaBar barrel.
One coordinate is measured by the position of the scintillation bar.
The other coordinate by measuring the time at both end of the bar.
Need input from simulation and background evaluation.
Time resolution and spatial segmentation
Number and location of active layers.
Need full simulation of the detector, reconstruction code and muon selectors.
From CDR: possible 4 fibers readout

6. Evolution from CDR
Some of the questions that we need to answer for TDR
Number of fibers per scintillation bar
WLS fiber diameter (1 mm), shape decay time, …
Use Geiger Mode APDs instead of APDs
What is the best mechanical design
What electronics
Read one or two side of the scintillator ?  ?   ?   ?   ?  ? ?

7. The scintillator bars In contact with FNAL-NICADD facility
Various candidates:
We have some spares from Minos and Itasca company that we are using for R&D

8. From Orsay to Perugia and beyond
End of Orsay meeting
R&D needs
evaluate different readout options
evaluate the possibility to bring the photon-detectors out of the iron
impact of neutron background on SiPM
Iron Structure: new structure vs partial recycle of BaBar iron (or total recycle)
impact on the budget
impact on the performances
Now
studies in progress + simulation needed
studies completed (will be reported in this meeting)
preliminary tests done
first cost evaluation
waiting for the simulation

9. Different readout options:
1st option: measure both coordinates with one
scintillation bar (position + time).
This is the baseline for the barrel.
1st option
As 2-nd option we are considering the “double coord layout”: orthogonal scintillator bars, 1cm thick (mechanically rather complicated for the barrel)
2nd option
Sketch of the two readout options

10. Light loss in the CLEAR fiber
WLS and clear fiber are coupled mechanically, no splicing
We expect roughly a 10% coupling loss
L= 10m, att length l = 10m
Aexp = Acoupl e-l/L ~ 0.9 * 0.37
~ 0.33
Ameas=146/446 = 0.33
This confirm our estimate for the fibers coupling loss
After 10m of 1.5 mm clear fiber
No clear fiber
<Q> = 146 ch
<Q> = 446 ch
ADC ch

11. 1 vs 2 vs 3 kuraray fibers at the close end (CLOSE end: ~0
1 vs 2 vs 3 kuraray fibers at the close end (CLOSE end: ~0.3m from scintillator)
1 fiber
R2/1 = 1.46
R3/1 = 1.65
ADC ch
With 3 fibers we
gain only 13% more signal wrt 2 fiber case
2 fibers
3 fibers

12. From Orsay to Perugia and beyond

13. SiPM currents and dark rates

15. If preliminary results will be confirmed SiPM can be damaged with a
dose of 109 n/cm2
Need for accelerator background simulations + study on neutron shielding

16. From Orsay to Perugia and beyond

17. Flux return - - - - CDR baseline = 920 mm Babar IFR thickness:
Barrel = 650 mm
Doors = 600 mm
Some parts of Babar have been thickness increased with brass and steel plates
Current thicknesses (equivalent):
Barrel ~ 795 mm
but last instrumented layer see 695 mm
FW doors ~ 835 mm
BW doors = 600 mm - -
Babar IFR with brass filling:
Barrel maximum thickness ~ 868 mm
but last instrumented layer see ~ 768 mm
FW doors maximum thickness ~ mm
BW doors maximum thickness ~ 900 mm
Which solution? Scenarios:
Doors: brass filling + 100mm steel, refurbish BW doors as FW ones (up to 920 mm)
Barrel:
brass filling + modify arches and cradle to allow outer scint. layer ~ 868 mm
Add 100mm plate outisde + new arches and cradle + 1 layer brass ~ 915 mm
Replace inner wedges + modify cradle and arches = 920 mm
CDR baseline = 920 mm -

18. Flux return cost evaluation
Mass Cost
Current IFR (wedges + doors + cradle + arcs): t (0.4 M€ transportation cost)
Different scenarios
Brass filling, 868 mm, arches and cradle modified 900 t M€
Brass + steel up to 920 mm doors and barrel t M€
New inner wedges, no brass t M€
Fully new IFR, max. thickness t M€
(950mm barrel, 1100 mm doors)

19. From Orsay to Perugia and beyond

20. Digitizer + clusterizer

21. From Orsay to Perugia and beyond

23. From Orsay to Perugia and beyond

24. Prototype preparation
layout based on:
5 layers of x-y scintillators, 1 cm thick, read in binary mode
3 layers of scintillators 2 cm thick, read in timing mode
Design of the prototype has started and will be finalized based on R&D and simulation.
Need to place the order for the scintillators by September: schedule for simulation is very tight.
SCINTILLATORS/FIBERS
IRON
FRAME
Electronics for the prototype is being designed to test different readout options.
Cooling system and other infrastructures to be developed.

25. From Orsay to Perugia and beyond

26. Milestones toward the TDR
order scintillators for prototype construction (needed simulation results)
finalize prototype design (mechanics and electronics) and begin construction.
begin prototype assembly
prototype test with cosmics
test beam
write TDR
September 09
Fall 2009
January 2010
Spring 2010
Summer 2010
Fall 2010
A lot of work to be done, but it seems we are on the right path