Mechanical and Cooling Specifications - *DRAFT*

Vacuum Pressure

10^-6 Torr

Maximum Radiation Dose

1X10¹⁴ 2 GeV electrons (~3X10¹³ 1MeV NEQ)

Maximum Magnetic Field

0.55 Tesla

Target

0.125% X₀ Tungsten (approx. 4 microns thickness)

# tracking planes

5

two modules per plane, one above and one below the dead zone

Sensors per module

2, in small angle stereo configuration

Stereo angles L1; L2; L3; L4; L5 (mrad)

(0/100); (0,100); (0,50); (0,50); (0,50)

stereo sensors dip away from dead zone on electron side. Stereo sensors rotated about centers.

Nominal dead zone between non-bend sensors w.r.t. photon line (y positions)

+/- 15 mrad

between sensitive regions

z-positions from target (mm)

100, 200, 300, 500, 700

x-positions w.r.t. photon line

0 in all layers

y movement (motorized)

top and bottom halves move separately in y with +/- 20 mm range

for nominal positions see dead zone specification above

pitch movement (motorized)

+/- 20 mrad

implied by y adjustability above at both ends in z

yaw movement (manual)

+/- 20 mrad

nominal bias voltage

150V

maximum bias voltage

500V

Material

<1% X0 per measurement pair averaged over tracking volume

Sensor Temperature

<0C over entire sensor before irradiation

APV25 Temperature

<30C for all chips

APV25 Temperature Stability

constant within 3C during physics running

does not include chip to chip variations, which can be larger

Flatness

all sensors planar within 50 microns total

includes thermal deformation

Non-bend Alignment of planes

within 0.5 mrad for all modules on each side of dead zone

means strips are projective to within 1 strip over entire solid angle

Stereo Angle Consistency

within 0.5 mrad of nominal in all layers

Bend-plane alignment stability

within 10 microns over all sensor surfaces on each side of dead zone during all running

Non-bend alignment stability

within 25 microns over all sensor surfaces on each side of dead zone during all running

Z alignment stability

within 50 microns over all sensor surfaces on each side of dead zone during all running