1 03/21/2006 GLAST CU Beam Test Workshop Scanning Table

2 03/21/2006 Specifications Rotary plate Rotation 360° Speed 1 rpm Precision < 0.5° (TBC) Instrument Weight: 750 Kg Carriage Stroke 1500 mm Speed 25 mm/s Precision +/- 0.5 mm Lifting plate Stroke 400 mm Speed 5 mm/s Precision +/- 1mm Lower position Height 850 mm Top position Height 1250 mm Displacements allow full scanning of the CU Slow speeds to minimize dynamic loading Speeds allow full stroke in 1 or 2 min

3 03/21/2006 Table control All 3 axis motorized with stepper motors –Open loop control: no feedback on true position 1 electronic board controlling 1 power module per axis –Modules mounted inside a control box attached to the carriage PC connected to the control board to send move orders to the table –Local connection or cable from the control room –Serial link, optionally internet protocol (requires add-on bard) Basic program language to communicate with the control board –“move to xx position” type of commands –Routines available to specific tasks: reference position Development of simple GUI is planed for a more user-friendly control of the table Reference position of the table defined by precision limit switches –Sensitivity +/- 1 motor step: negligible

4 03/21/2006 Test Area Requirements Space for to operate the table with CU mounted –3x3 m² if 360° rotation of CU Distance between ground and beam ~1300 mm –Ok for PS beam –Something needed at SPS to raise the table Cement blocks? Additional removable structure? Services –Power supply for the table control box Standard 220AC, around 1 KW needed Handling of table –Plan is to have removable wheels to bring to table close to the test areas –Lifting equipment probably needed to position it in the beam (weight around 300 Kg)

5 03/21/2006 Interfaces Electrical: NA Mechanical –Very simple due to CU mounted on large, stiff plate Threaded holes for fasteners: already in the design based on current CAD model of the interface plate Eventually additional holes for alignment pins Cables –Only a few cables coming in and out of the CU but still a concern due to large strokes of the tables Specific features need to be designed to deal with them

6 03/21/2006 Security Security features on table –Limit switches on 3 axis cabled on control board –Mechanical stops –Brake on motor lifting the table: won’t fall in case of power shutdown –General electrical shutdown CERN Approval –Concern maybe not a problem: everything needs to be arranged before the table is sent to CERN –First contact with CERN security personnel but no feedback yet –Table should not fit in lifting equipment category but in machinery: needs to comply with European directive 98/37/CE Certificate of Compliance required? => additional work, delay…

7 03/21/2006 Resources - Planning Budget: ok for 25 k€ –Money should be available by now at LLR: on time –Table more expensive than expected but most of the mechanical fabrication and assembly is done internally: compensates Manpower: ok –Personnel from LLR available to deal with mechanical, electrical and software aspects Planning: still on time –Mechanical design almost done: features to rotate the CU need to be reworked –First release of engineering drawings: allow fabrication work to start –Mechanical and electrical components chosen Purchase order in early April, components available mid-May –1 month for assembly and 2 weeks to test Table ready in early July: safety margin is 2 weeks before shipping to CERN

8 03/21/2006 Height of the table Design of the table doesn’t meet the requirements: 850 mm instead of 800 in lower position –Distance between center of top CsI log and edge (400mm) is more than 50 mm –Easy solution is to change/remove the anti-vibration feet Ok: grid reduced by an additional 42 mm