Commissione Scientifica Nazionale III
Bari 15 settembre 2014
L’esperimento JLAB12: stato e prospettive
M. Battaglieri & G.M. Urciuoli
per conto della collaborazione JLAB12
INFN-GE – INFN-RM1
Italy
Measurement of the Target-Normal Single-Spin Asymmetry in Deep-Inelastic Scattering from the Reaction 3He↑(e,e’)X
Phys. Rev. Lett. 113, art. no. 022502 JUL 11 2014
SuperBigbite Spectrometer in Hall A
Large luminosity
Moderate acceptance
Forward angles
Reconfigurable detectors
Background:
photon (250-500 MHz/cm2)
charged (160-200 kHz/cm2)
Physics:
Nucleon Form Factors
SIDIS – TMD’s
... Nucleon structure
Front tracker reused in
BigBite
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Silicon Detectors
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12
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GEM
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Main Technical solutions
 Use the COMPASS approach: 3xGEM, 2D readout - one significant difference: use new single mask GEM foil
(instead of double mask) – cheaper and faster production
 Modular design: chambers consists of 3 independent GEM modules (40x50 cm2) with thin dead area
 Electronics around the module, direct connection; 90 degree bending between modules
 External support frame in carbon fiber (long bars) to minimize thermal deformation
40x50 cm2
module
Front Tracker Chamber: 40x150 cm2
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GEM Module construction process
Module production fully established in INFN-Catania
Electronics preliminary QA in Genoa
Module integration and characterization in INFN-Sanità
Electronics
Test
GEM Foils
HV curing and
quality test
Production rate
2 modules in 3 months
Stretching
Assembling
gas lines
(improvement under development,
no signficant impact on cost/production)
7 July 2014 - JLab
Finalization
(solder resistor, check HV)
SBS Coll. Meeting - Front Tracker GEM
Gluing
Put together
(align on reference pins)
Glue Curing
in vacuum bag
(>24 h)
Clean room
Electronics integration
Test and characterization
by rad. source and cosmics
Permaglas Frames
Visual Inspection
Ultrasound bath
cleaning
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SBS GEM Tracker - Test Beam / Jan 2014
Small scale final
system (gas,
LV, HV
monitored)
Main Goals:
 Characterize
chambers in
terms of charge
sharing,
efficiency and
spatial
resolution at
different HV,
gas mixture.

Figure out the
gain variation
of the previous
test
3 Big GEMs
DESY/EUDET
Pixel Telescope
Reference
Small GEM
1-4 GeV
Electron
Beam
AIDA-EUDET support
→ Got lot's of good data with high spatial resolution information
from pixel telescope
→ Stable performance (“all” conditions carefully monitored)
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Sij – neuron (0 or 1) – connection between two points
Track Association by NN / Simulation
Energy
j
Vi
Neuron changing rate
Kalman Filter Reconstruction: simulation
Residues
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GEM Production and Test Status
Produced or
Assembled
Tested
NOT Accepted
Comment
GEM foils
51
25
7
2 can be probably
recovered
Readout+Honeycomb
15 / 18
7
1
Bad gluing
GEM Module
6
3
1
N2 gas cleaning to be
done
Front End Electronics
250*
60
2
VME Modules
28
10+
2
Backplane
80
20+
1
Patch Panel
50
many
many
Minor fix
returned to company*
• The very first 4 GEM foils did not pass the original quality checks, 3 recent GEM foils of the same
bunch did not pass the new quality check
• One readout + honeycomb suffered bad gluing (probably still usable)
• 2 of the GEM modules passed preliminary tests but then degraded significiantly (large dark
current); one recovered after N2 gas cleaning.
• * soldering problem, bug fixed by the company
7 July 2014 - JLab
SBS Coll. Meeting - Front Tracker GEM
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GEM Tracker Activity 2014-2015
• Continue Production
• Test, Characterization and Calibration of GEM and electronics
• Fix damaged modules/material, replace if no fix possible
• Finalization of a rubust and efficient track reconstruction algorithm
• Complete and test the complex firmware of the DAQ
• Study (and solve) open issues
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Electronic (GEM + Silicon detector)
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Electronics for GEM and SiD
VME Module (MPD) ver. 4.0 firmware upgrade
• Revised memory mapping
• Event builder implemented and simulated:
– Multiblock (compliant to JLab request)
– 24 bit, packed to 32 bit on 64 bit boundary for efficiency
– 128MB FIFO data buffer using DDR2 SDRAM (pretty complex code)
• D64 read only cycle implemented: MBLT, 2eVME, 2eSST (3 cycles):
– 2eSST tested on STRUCK SIS-3104 (2 Gb/s optical link that limit the band)
CYCLE
DATA period
Simulated peak speed
Readout Average Speed
2eSST160
6 ck = 54 ns (3s/3h)
148 MB/s
117 MB/s
2eSST267
4 ck = 36 ns (2s/2h)
222 MB/s
124 MB/s
2eSST320
3 ck = 27 ns (2s/1h)
296 MB/s
124 MB/s
• To be done
– Multiboard block transfer
– Firmware for fiber optic protocol (important if modules will sit near the front-end electronics)
– Deep debug and test (implies rewriting of some DAQ code)
– Minor development to reduce backplane material budget and add flexible kapton bus (for SiD)
– Study long cable induced noise
7 July 2014 - JLab
SBS Coll. Meeting - Front Tracker GEM
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HCAL
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Hcal
Italian activity
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HCAL 2014-2015 activity
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Analysis
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9Be(e,e’K)9Li
L
(G.M. Urciuoli, F. Cusanno et al. Submitted to PHYS REV C)
Experimental excitation energy vs Monte
Carlo Data
(red curve) and vs Monte Carlo data with
radiative
Effects “turned off” (blue curve)
Radiative corrected experimental
excitation energy vs theoretical data
(thin green curve). Thick curve: four
gaussian fits of the radiative
corrected data
An elementary model for the (e,e′K+) reaction with a different
balance of spin-flip and non-spin-flip amplitudes might help to
resolve the disagreement with theory of the relative strenght of
the peaks in the doublets
Experiment E07-002
Present result for KLL in E07-002 seems to confirm previous measurement of E99-114,
at a different angle. Work in progress.
Study of systematic uncertainties is undergoing.
Optimize analysis in order to conclude that at our energy
regime, pQCD predictions are excluded.
With those points included, ready for
publication
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Studies on 3He as neutron effective target in SIDIS
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