1. Physics program in Hall A for the CEBAF 12 GeV era
SBS Physics
Nucleon Form Factors (FFs)
SIDIS, TMDs
Nucleon Structures
SBS detectors:
Large Luminosity & moderate acceptance
Independent arm (re-configurable detectors)

2. GEM Trackers of the Super Bigbite Spectrometer (SBS)
Front Tracker (FT): INFN Roma & Catania (E. Cisbani)
6 layers (1st tracker) with an active area of 150 cm * 40 cm
Each layer: vertical stack of 3 (50 cm * 40 cm) triple GEM modules
Production: 18 modules
Back Tracker (BT): University of Virginia (N. Liyanage)
2 * 5 layers (2nd & 3rd trackers) of an active area of 200 cm * 60 cm
Each layer: vertical stack of 4 (60 cm * 50 cm) triple GEM modules
Production: 40 (+ 5) modules
BT layer
(2nd & 3rd Trackers)
FT layer
(1st tracker)
60 cm * 50 cm
BT Module
50 cm * 40 cm
FT Module
Proton arm of the SBS spectrometer in the Gep(5) configuration

3. Construction and Characteristics of the SBS GEM modules
Prototype of the Back Tracker module
Front Tracker layer with the APV25-MPD FE cards
Spatial resolution
Uniformity
Charge sharing
sx =58 mm