NSW alignment Layout Alignment Bars and BCAMs Design

NSW alignment Layout Alignment Bars and BCAMs Design Andrey Dushkin, ( Brandeis University) March 12 2015, CERN

Summary q All alignment related documents can be found in the BNL database http: //atlas 3. b 459. bnl. gov/DDB/default. aspx? id=203 q Alignment layout • Alignment scheme and number of alignment lines defined • Layout of proximity and azimuthal lines completed and posted • Layout of source platforms on MM and TGC chambers completed however number of sources is not completely defined and will be based on simulations • Proposed layout of the additional interconnects completed and posted q Alignment bars • Number and position of the alignment bars defined • In-bar alignment scheme defined, design of the in-bar mechanics and electronics completed, drawings posted • 3 D-model of the L and S bars completed and posted q BCAMs • Type and number of the BCAMs defined • N-BCAM designed, drawings posted, H-BCAM slight modifications needed

NSW alignment system Old (current) alignment system Polar BCAM Mask L-Bar S-Bar Proxy camera Azimuthal line Azimuthal BCAM Proxy line Source Polar BCAM Alignment bar Source platform In the current Small wheel 8 alignment bars located in the cavity between to large chambers and alignment elements “look” into a gap of 40 mm between large and small sectors. Three proxy cameras that are mounted on a platform glued to one side of a chamber(IP side for L and HO for S chambers) viewing RASNIK masks on either bar or adjacent chamber. In addition there a saloon door sources that are viewed by azimuthal BCAMs. Basically all alignment lines are in one plane between large and small sectors with exceptions of two polar alignment lines. Such a scheme successfully works since each chamber treated as a one object, precisely built and its shape monitored by in-plane alignment system. In the New Small Wheel Large and a Small sectors have four individual layers of either chambers(MM) or wedges (TGC), each treated as one alignable unit that have to be monitored. The current scheme- adding another 8 “S” alignment bars to the existing 8 “L” bars (16 in total per wheel) then linking modules/wedges in large sectors to the two adjacent “S” bars and those in small sectors to the adjacent “L” bars. There are two planes of proxy lines per sector that runs in the gaps between TGC and MM wedges and one plane of azimuthal lines in-between large and small sectors.

L-Proximity lines Fiber with a ferrule at the end Source platform S-Bar Kinematic triplet S-Proximity lines Azimuthal BCAM L-Bar Source platform MM Azimuthal lines In more detail one Large and one Small sectors with two pairs of bars(L-Bar and S-Bar). Proxy BCAMs on a bar viewing sources assembled on a TGC and a MM chamber surfaces. One proxy line (BCAM to BCAM) picks 3+3 sources on both MM and TGC. In each source platform there are four precision holes drilled. Once platforms installed fibers with precision ferrules at each end that delivers the light from a light injector installed. Platforms precisely glued and surveyed w. r. t. a precision pins(MM) or a V-slot and a flat(TGC). Source platform precision holes measured on a CMM w. r. t. a built in kinematic triplet. Each BCAM calibrated w. r. t a built in kinematic triplet. BCAM sit on a three spheres glued into a bar clamp. Spheres position measured on a CMM w. r. t. a bar survey rings. Sources align chambers(wedges ) to a bar. Azimuthal BCAMs align bars within a wheel. Polar BCAMs align bars to other wheels. Survey ring Source platform TGC Proxy BCAM Mid ETA polar BCAM High ETA polar BCAM

Source platforms on a large MM. There are six proxy BCAM lines on IP side and six on HO side of the bar running across one large sector. Three source platforms glued on a chamber surface along each line. The mid platform has four sources shining in both direction two outer ones have two sources shining at far BCAM. Outer platforms glued on top or close to a quadruplet frame. The interconnect have to be placed in close vicinity of the mid platform in order to minimize unpredicted movement of the platform due to a surface deformation once quadruplet pressurized. Three proxy lines per each quadruplet. Source platforms on a large TGC. The same six proxy BCAM-BCAM lines on IP side and six on HO side of the bar running across one large TGC wedge. Three source platforms glued on a chamber surface along each line. The mid platform has four sources shining in both direction two outer ones have two sources shining at far BCAM. Outer platforms glued at 10 -15 mm distance from the TGC frame. There is one proxy line across TGC 1 , three across TGC 2 and two across TGC 3.

Current scheme of the NSW alignment lines and on-chamber source platforms. Large sector. Documents can be found in the BNL database http: //atlas 3. b 459. bnl. gov/DDB/default. aspx? id=203 Large micromegas chambers proxy, azimuthal lines and source platforms layout. Large TGC chambers proxy, azimuthal lines and source platforms layout.

Source platforms on small MM. There are six proxy BCAM lines on IP side and six on HO side of the bar running across one small sector. Three source platforms glued on a chamber surface along each line. Same arrangements of sources as for the large sector (2+4+2) and same requirements applies to the platform and interconnect locations. Three proxy lines per each quadruplet. Source platforms on small TGC. The same six proxy BCAM lines on IP side and six on HO side of the bar running across one large TGC wedge. Three source platforms glued on a chamber surface along each line. Same arrangements of sources as for the large sector (2+4+2) and same requirements applies to the platform. There is one line proxy line across TGC 1 , three across TGC 2 and two across TGC 3.

Current scheme of the NSW alignment lines and on-chamber source platforms. Small sector. Documents can be found in the BNL database http: //atlas 3. b 459. bnl. gov/DDB/default. aspx? id=203 Small micromegas chambers proxy, azimuthal lines and source platforms layout. Small TGC chambers proxy, azimuthal lines and source platforms layout.

BCAM Light injector Source platform on TGC Source platform on MM Mock-up for one proxy line built at Brandeis. Two panels 185 x 22 sq. sm were glued on the granite table. Each panel has one side perfectly flat. On this mock-up we study different arrangements of the source platforms and different gaps, misplacement range of either bar or wedge that system can tolerate, reflection from the surfaces and ways to block it, effects from the surface distortion and we can also check whether simulation results correlate with our measurements.

Proposed Micromegas chambers interconnects layout. Documents can be found in the BNL database http: //atlas 3. b 459. bnl. gov/DDB/default. aspx? id=203 Large MM chambers. One Circles in red shown on both sides of the source platform. Only one interconnect close to platform is needed. Construction sites have to decide which one to pick. Small MM chambers.

BEE alignment to be incorporated into the NSW BEE alignment scheme BEE sources BEE 1 BEE 2 BEE proxy BCAMs held by a L-Bar. BEE proxy BCAM SW polar BCAM SW alignment bar ECT Two BCAMs mounted on a platforms attached to a small MDT chamber face away from IP viewing sources on the BEE chambers. These BCAMs have to be incorporated into a NSW.

BIS 78 alignment idea BCAM sitting on the Lbar looking at sources on BIS 78 chamber. Additional BIS 78 alignment platforms on a small TGCs, IP side. Platforms to be glued during TGC wedge assembly at CERN. Camera mounted on the TGC looking at RASNIK mask on BIS 78 chamber.

In-bar alignment layout for EI bars. CCD sensors are at the both ends of the bar and the two bar-heads mounted on the end-caps and CCDs connected with flex cables to the barheads. Two cables routed to the both ends of the bar from the repeaters. Internal routing to the LEDs and temperature sensors done from both bar-heads. In-bar alignment layout for the NSW bars. CCD sensors moved as far from high radiation region as possible. One bar-head mounted on the bar-head station located in-between two CCD stations. There is one cable ran from the repeater to the bar. Internal routing – four twisted pair wires routed from the entry circuit board mounted on the end-cap to the barhead. From the bar-head two twisted pair wires routed to the mask stations and two flex circuit board run to the CCD stations.

Mask station CCD station Lens station Bar head Flex circuit Bar head station Mask station CCD station Conduit In-bar alignment prototype tested on the test beam Lens station End cap with entry head CCD station Lens station Mask station Each in-bar alignment set attached to a moving platforms on the test beam. Cables cut to a length, connectors added. The whole system turned on. Position of the stations adjusted if needed and recorded. That record is shipped alone with complete in-bar alignment set to Freiburg.

In-bar alignment elements Mask station CCD station Bar-head station Lens station All in-bar alignment parts drawings are final and can be found in the BNL database http: //atlas 3. b 459. bnl. gov/DDB/defa ult. aspx? id=203

New low profile short focal length BCAM (N-BCAM) Same kinematic mount pattern as for an old BCAM. Existing calibration stand planned to be used. New radiation hard CCD Shorter Lens-CCD distance Detachable front plate Flexible circuit board technology Laser circuit board

N-BCAM-BLACK assembly drawing. Machine shop drawings can be found in the BNL database http: //atlas 3. b 459. bnl. gov/DDB/default. aspx? id=203

New high profile short focal length double ended BCAM (H-BCAM) H-BCAM was developed by OSI. We will use their design though small mechanical modifications are needed in order to simplify assembly process.

NSW versus current bars. Current bar The current Small Wheel alignment elements (BCAMs, masks) are all facing one side (IP). The bar is recessed into the space between two large chambers with alignment elements stick into the 40 mm gap between Large and Small MDT chambers where all the alignment corridors are running. The off-center position of the elements rather close to the bar. Exceptions are two polar BCAMs. NSW L-bar In the New Small Wheel we have four 27 mm gaps in-between TGC and MM wedges (37 mm surface –to-surface), two in Large and two in Small sectors where proxy alignment corridors are running. In addition L and S bars are linked with azimuthal lines. Their corridors are running in the 60 mm gap between Large and Small sectors. L and S bars lined up with the center of the MM frame in their respective sectors. Alignment elements located on both, IP and HO sides of the bar and they are a mirror symmetry w. r. t. the bar axis. At the out most extremity of the L-bar( the one shown) there are rather bulky clamps to support polar, BEE and BIS 78 BCAMs.

NSW L-BAR model MUX BPX_R 4_HO BPX_R 5_HO BPX_R 2_HO BPX_R 1_HO SRG_R 1 GMB SLRG BPX_R 4_IP BPX_R 2_IP BPX_R 1_IP BAZ_R 2 BAZ_R 1 BPX_BEE BPX_BIS 78 BPL_R 1 BPX_R 3_HO BPX BCAM proxy BPL BCAM polar BAZ BCAM azimuthal MUX multiplexer SRG survey ring GMB gimbal SLRG slip ring MUX BPX_R 6_HO MUX SRG_R 2 BPX_BEE BPX_R 3_IP BPL_R 2 BPX_R 6_IP BAZ_R 3 BPX_R 5_IP

NSW S-BAR model BPX_R 4_IP BPX_R 2_IP MUX BPX_R 1_IP SRG_R 1 BAZ_R 3 BPX_R 4_HO BPX_R 2_HO BPX_R 1_HO BAZ_R 1 BPX_R 6_IP BPX_R 3_IP BPX BCAM proxy BAZ BCAM azimuthal MUX multiplexer SRG survey ring GMB gimbal SLRG slip ring BPX_R 5_IP GMB SLRG BPX_R 3_HO BAZ_R 2 SRG_R 2 BPX_R 5_HO BPX_R 6_HO

Production plan In-bar • • • Procurement of the mechanical stuff and electronics Once received, assembly subassemblies(CCD station, Mask Station, Lens station, missing components on a circuit boards etc. ) Assembly one set at the time on a test beam, wire stations. Test complete set and adjust stations if needed Record position of stations into in-bat alignment set passport Ship to Freiburg along with related documentation On-BAR • • • Complete machine shop drawings of the clamps for L and S bars Upload machine shop drawing files along with 3 -D models in the BNL data base Complete sphere coordinate file for each bar type that will be used in CMM measurements BCAM • • • Complete changes to the H-BCAM Procurement of the mechanical stuff and electronics Once received, assembly subassemblies(front plate with LED circuit board, missing components on a circuit boards etc. ) Assembly and test BCAM on the test beam. Calibrate each BCAM and record calibration data Ship to CERN