1. FSC status and plans Pavel Semenov IHEP, Protvino
28 Jan 2005
FSC status and plans
Pavel Semenov IHEP, Protvino
on behalf of the IHEP PANDA group
PANDA Collaboration meeting, Turin
15-19 June 2009

2. Pavel Semenov, PANDA Collaboration meeting, Turin
Outline
MC simulations: to set detector requirements (Nikolay Minaev)
On the way to the full FSC simulation in PandaRoot (Dmitry Morozov)
Photodetector selection
List of reqs to FE and DAQ
Some new preliminary results of prototype 55x55 testbeam
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

3. Fast MC (photons energy distribution)
All photons energy (upper curve)
over photons at the Shashlyk
aperture (color curves)
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

4. Photons in the FSC, 6.27 GeV/c beam
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

5. Charmonium study, 6.27 GeV/c beam
Energy of photons from charmonium decays going to FSC is relatively small,
registration threshold should be similar to EMC
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

6. Pavel Semenov, PANDA Collaboration meeting, Turin
FSC in PandaRoot
Implementation of the optical model proved by testbeam measurements is underway
FSC geometry in PandaRoot is defined. Forward spectrometer geometry inconsistency found
Geo Mapper compatibility problem – in the current version FSC dimensions are hardcoded
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

7. Shashlyk module internal structure
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

8. FSC geometry and position
To check the
FSC geometry
description the
complete forward
spectrometer was
drawn
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

9. The last DCH Overlaps with FSC
Either position
or a size of the
DCH is incorrect.
Also forward
TOF wall is
missing
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

10. Photodetector selection
The goal was to select and test several PMT’s types (noise, dyn.range, rate effect, signal width, long term stability, dimensions)
Now we are in the process of buying samples from Hamamatsu and ElectronTubes (Photonis “temporarily” doesn’t produce PMTs)
R1925 looks attractive (like R7899 but more compact, only 43 mm and green enhanced)
ETL 9085B – compact, good stability, but expensive
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

11. FSC list of reqs for FEE and DAQ
Signal dynamic range 3 MeV- 15 GeV
Noise 1-3 MeV ? (testbeam showed pedestals sigma 5-6 MeV, mainly due to correlated pickup)
Hit rate 1 MHz near beam pipe, 300 kHz detector edge (per channel, energy over threshold)
Photodetector (PMT) signal (10 ns + 40 ns) goes directly to sampling ADC (180 MHz, 12 bits?) with 3 meter cable
Data size ~10 samples per event per channel
Overall channels: 1500, typical event size 3-5 photons (~100 amplitudes after feature extraction)
Tracking system information can be used to reduce data flow
Light injection monitoring system events readout
Prototype tested with slow ADC, next testbeam to test shashlyk performance with sampling ADC (Uppsala SADC?)
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

12. Proto64 (55x55 mm2 cell) testbeam results
Preliminary results:
Energy resolution dependence on electron energy
σE /E = 5.6/E  2.4/√E  1.3 [%]
σE /E = 3.5/E  2.8/√E  1.3 [%] Big cell prototype
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

13. Pavel Semenov, PANDA Collaboration meeting, Turin
Summary
MC simulations to set detector requirements show that for charmonium physics FSC should have good performance at relatively low energy (1.5 GeV and lower)
FSC implementation in PandaRoot framework is underway
Testbeam shows energy resolution for the small cell size similar to the big cell prototype
Getting ready to make a photodetecor and type of FEE choice
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

14. Pavel Semenov, PANDA Collaboration meeting, Turin
Backup slides
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

15. Shashlyk signal shape (cosmic muons)
Rise time ~10 ns,
tail ~40 ns
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

16. Pavel Semenov, PANDA Collaboration meeting, Turin
Shashyk module sizes
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

17. Shashlyk module tail stucture
Two types of possible mounting
of the module: 4 tubes or 1 screw
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

18. Overall design of the FS EMC
27x14 modules
(4cells each)
Frame sides to put FEE crates
(~3 meter signal cable from
PMT to ADC)
Back plate to fix modules
in Z direction (modules
position from one side and
photodetectors from the
other side of the plate )
Accelerator pipe hole
(2x2 modules) shifted
from the center
Dedicated rail system
for maintenance procedure
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

19. Pavel Semenov, PANDA Collaboration meeting, Turin
Detector sizes
Active zone 2970x1540 mm2
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

20. Time between energy depositions (one cell)
Near pipe
Detector vertical edge
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

21. Calorimeter at the maintenance position
To provide a possibility
of Shashlyk maintenance
A dedicated extensible
rail system is proposed.
Calorimeter can be
shifted out to the left or
the right side of the
Forward Spectrometer.
At the working position
it fixed by lock pins with
high precision
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

22. Pavel Semenov, PANDA Collaboration meeting, Turin
Testbeam setup
DC1
M14
DC2
DC3
DC4
ECAL
Target
Beam S3 S2 S1 St SA
Spectrometer consisted of 4 drift chamber stations and a magnet to measure beam particle momentum precisely
Calorimeter prototype
Al target at 1.5m and 3 m before the prototype
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

23. Testbeam results for 1.5 m (more sophisticated analysis)
Shower profile fit,
Charged hadrons removed (drift chamber),
Rough calorimeter calibration
π0 1-2 GeV, σm 12.5 MeV
Next steps:
Precise calibration,
All data analysis,
Big and small cell
performance comparison
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

24. New prototype parameters
64 cells (16 supermodules) assembled in matrix
380 layers of 0.3-mm lead and 1.5-mm scintillator, total length 680 mm
Transverse size 55x55 mm2
Effective Moliere radius: RM=59 mm
Effective radiation length: X0=34 mm
Total radiation length: 20X0
Light collection: 36 fibers BCF-91A (1.0 mm)
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin

25. Prototype modules production
14-19 June 2009
Pavel Semenov, PANDA Collaboration meeting, Turin