GEM detector configuration Stations 1 4 12 stations

GEM detector configuration Stations 1 - 4 12 stations: Z = 30 – 45 – 60 – 80 – 100 – 130 – 160 – 190 – 230 – 270 – 315 – 360 Stereo angles: 0 – 7. 5 deg in stat. 1 -4; 0 – 15 deg in stat. 5 - 12 Pitch: 400 um in stat. 1 -4, 800 um in stat. 5 -12 14 -oct-2014 A. Zinchenko 1

GEM plane Xsize, cm Ysize, cm dx / dy, см Zcoord-Ztarget hot zone 1 -2 60 60 3 / 7 / 12 / 18 30, 45 3 -4 80 80 4 / 9 / 15 / 25 60, 80 5 130 (2 x 66) 80 (2 x 41) 15 / 10 100 (prototype) 6 -7 160 80 (2 x 45) 40 / 15 130, 160 8 -12 200 80 (2 x 45) 50 / 20 190, 230, 270, 315, 360 R(beam pipe)= 2. 5 cm (1 plane), 5 cm (12 plane), linear rise, δ=1 mm, carbon dz 1(frame) = 1. 5 cm (G 10), dz 2 (sensitive volume)=1 cm (~0. 7% X 0), dx 1, dy 1 (inner frame) = 1. 7 cm (G 10), dx 2(outer frame) = 5 cm (G 10), dy 2 (outer frame) = 3. 75 cm (G 10), dz 3 = 2. 5 cm (G 10), spacers: net 10 x 10 cm, width / thickness 2 x 6 mm fiber glass, eff→ 0 Strip pitch (1 -4 planes) = 0. 4 mm, strip pitch (5 -12 planes) = 0. 8 mm

Structure of GEM plane 5 (4 x 66 x 41 cm, prototype) y R dy 1 x ysize dy 2 dz 3 xsize dx 1 dx 2 dz 3 dz 2 z dz 1 x dz 3

X‘ coordinate (odd planes 1, 3, 5, …): 2 1 1 quarter: +75 degree 2 quarter: +105 degree 3 quarter: -105 degree dy 3 dx 4 quarter: -75 degree 4 X‘ coordinate (even planes 2, 4, 6, …): 1 quarter: +105 degree 2 quarter: +75 degree 3 quarter: -75 degree 4 quarter: -105 degree X coordinate (odd and even plane): +90 degree spacers Structure of strips in GEM plane 5 (4 x 66 x 41 cm prototype)

Structure and length of strips in stations 1 -2, 3 -4

Geometry of the JINR GEM 1632 x 450 chamber R/O board width: 35 mm (max) R/O connectors Place for HV divider 00 strips +150 strips Right R/O board Left R/O board 450 HV 779. 9 (inner zone) 420. 1 150 R 40 5 Installation holes (Ø~5 mm) 400 1632 Boundary of the Left and Right R/O boards Number of strips Left R/O board Right R/O board X(00) strips Outer zone 1020 Inner zone 525 500 X(150) strips Outer zone 1131 Inner zone 507 531 3183 3182 25 25 Total strips: R/O Connect. (128

Specification of the Triple GEMs based detector prototype for BM@N (Baryonic Matter at Nuclotron) experiment at JINR Dubna 1. Triple GEM with x, y readout from strips on anode pcb. 2. Active area 1632 x 450 mm 2. 3. X-strips(00) parameters: pitch: 800 µm, width: 160 µm, length: 150 mm, 300 mm, 450 mm. 1. Y-strips(+150): pitch: 800 µm, width: 680 µm, length: 155 mm, 311 mm, 466 mm. 1. Drift gap: 3 mm, gem 1 -gem 2 gap: 2. 5 mm, gem 2 -gem 3 gap: 2 mm, induction gap: 1. 5 mm. 2. Output 128 pins connector: CLE-170 -0 -DV 3. Support frame: width </= 15 mm, height </= 10 mm. 4. Place for gas, HV and output connectors possible on the left, right and upper ages only.