sid02

This is the version of the Silicon Detector modelled for the Letter of Intent (LOI) exercise.
The compact description of this detector in xml format can be found at http://www.lcsim.org/detectors/sid02.zip.

What follows is a plain text description of the file compact.xml found in this zip file.

Where a material is listed as xx% coverage, the density of the material has been reduced to xx% of its nominal value to mimic the effect of cutouts in the material. 

The tracking region is defined to be a cylinder with radius 126.5cm and z extent +/- 167.9cm.

Beampipe:

The beampipe consists of a cylindrical central tube and forward/backward conical sections.  The 0.040cm thick Beryllium central tube has an inner radius of 1.2cm and extends to |z|<6.25cm. The conical sections have a cone half-angle of 43.4mrad with an inner radius that flares from 1.2 cm at 6.25cm to 8.218cm at |z|=167.9cm. The conical sections are 0.0875cm thick Be for 6.25cm<|z|<37.5cm, where they transition to steel. The thickness of the steel section flares from 0.0875cm at |z|=37.5cm to 0.1992cm at |z|=167.9cm. A titanium liner on the inner surface of the beam pipe consists of a 0.0025cm thick cylinder and 0.0075cm thick conical sections.

Vertex Detector:

The vertex detector is composed of a central barrel system with five layers and forward systems composed of four disks.

Barrels 

The barrels are composed of .0113cm thick Silicon, of which the outer .002cm is sensitive, with the following inner radii and |z| extents:

Sensors are supported by cylinders made of 0.026cm thick carbon fiber with 25% coverage.

The cylinders attach to 0.026cm thick carbon fiber (25% coverage) bulkheads that span 1.44cm<r<7.16cm and have an inner |z| of 6.27cm.  The vertex detector is attached to the support tube by 0.026cm thick carbon fiber (25% coverage) support disks that span 1.44cm<r<16.87cm and have an inner |z| of 6.30cm.

Disks

There are four forward disks on either end, composed of a total of .0113cm of silicon, of which the inner .002cm is sensitive. The radial extent and inner |z| for the disks are:

The forward disk supports are 0.026cm thick carbon fiber (25% coverage) disks located as follows:

Readout Electronics and Cables 

For the barrel, readout electronics are modeled as G10 rings that are currently located outside the support membrances:

Forward disk readout electronics are modeled as inner and outer rings, both made of G10:

Barrel cables first are brought radially down to the beam pipe.  These radial cables are modeled as Cu disks:

 The remaining cable and service materials are located along the beam pipe. Inner cables are 0.012cm thick copper and run conically from an inner radius of 1.32cm at |z|=6.9cm to a radius of 1.455cm at |z|=10.0cm.  Service material is 0.3cm thick G10 that runs conically from an inner radius of 1.455cm at |z|=10cm to 1.542cm at |z|=12cm. Outer cables are modeled as copper that flares from a thickness of 0.010cm with an inner radius of 1.542cm at |z|=12cm to a thickness of 0.004cm with an inner radius of 8.310cm at |z|=167.9cm.

Support Tube 

The entire vertex detector is enclosed within a double walled carbon fiber support tube. The support tube walls are 0.05cm thick carbon fiber with inner radii of 16.87cm and 18.42cm and a |z| extent of |z|<89.48cm. The ends of the support tube double-walled disks of 0.05cm thick carbon fiber disks located as follows:

Tracker:

The tracker is composed of five cylindrical barrels with four disk-shaped endplanes. The z extent of the barrels increases with radius and the endplane for each extends beyond its cylinder in radius to provide overlap. The sensitive medium is silicon, assembled into carbon-fiber/Rohacell/PEEK modules and read out via a bump-bonded chip and Kapton/Copper cables. These modules are supported by carbon-fiber/Rohacell/carbon-fiber barrels or disks. Each barrel cylinder is supported from the next barrel out by an annular carbon fiber-ring. Outside each of these support rings in z, G10/Copper printed circuit boards are mounted for power and readout distribution to all silicon modules in a layer.

Barrels:

The radii and |z| extents of the barrel silicon layers are:

The estimated material thickness for modules, silicon, readout, and cables are averaged over the barrel and are given by:

The barrel support cylinders are composed of .05cm CarbonFiber, 0.80cm of Rohacell31 (15% coverage) and 0.05cm CarbonFiber. The inner radii and |z| extent are given by:

The barrels are supported by 0.05cm thick carbon fiber (15% coverage) rings:

Endcap:

Each layer is composed of two sensor modules to measure coordinates in two stereo (u-v) views. The table below shows the radial extent of the disks and the inner |z| position for the "A" and "B" sensor planes.

Each A plane has the following material thicknesses:

Each B plane has the following material thicknesses:

The endcap supports are disks made of two 0.05cm thick Carbon Fiber planes separated by a 0.63cm thick layer of Rohacell31 (15% coverage).  The radial span and inner z coordinate are:

Services

The readout and power distribution boards are mounted on the outside surfaces of the barrel support rings. The regions occupied by these boards and the average thickness of the material they represent are given by:

Note that in layer five, due to the constraints of the calorimeter, the readout boards are not mounted on this annular ring, but rather at smaller radius.

Forward Disks

There are also three forward disks at small angles composed of pixel sensor modules. The table below shows the radial extent of the disks and the inner |z| positions for the sensor planes.

 Each sensor plane has the following material thicknesses:

An x-y quarter view of the sid02 tracking detectors can be found at sid02_Tracker_QuarterView.eps
A plot of the material, expressed in percentage of a radiation length (X/X ₀ ), as a function of the polar angle, can be found at sid02TrackerMaterialScan.eps

Calorimeters:

Electromagnetic Calorimeter:

This element sets the basic size and aspect ratio for the rest of the detector. The inner radius for the barrel is 127cm. The aspect ratio is set to cos(theta)=0.8, meaning the inner z of the endcap EM calorimeter is at z of 168cm.

The EM calorimeter is a sampling calorimeter composed of 20 layers of

followed by ten layers of

There is a sensitive silicon layer before the first layer of Tungsten to provide additional electron/photon discrimination, giving a total of 31 layers of silicon readout.
The Tungsten alloy being used is TungstenDen24 (93% W, 6.1% Ni, .9% Fe) with a density of 17.8 g/cm ³ .
The endcap plug sits inside the barrel cylinder, so the barrel z extent is +/- 182.0cm.
The endcap starts at an inner radius of 20cm and extends out to 126.5cm.

Segmentation

The readout is 3.5mm x 3.5mm square cells.

Hadron calorimeter:

The hadron calorimeter is a sampling calorimeter composed of 40 layers of

It begins immediately outside of the EM calorimeters, with the endcap plug sitting inside the barrel.

The barrel inner radius is 141.0 with a z extent of +/- 294cm.
The endcap extends from an inner radius of 20.0cm to an outer radius of 140.75, inner z of 182.0.

Segmentation

The readout is 1cm x 1cm squares.

Solenoid:

The solenoid is modelled as a cylinder with an inner radius of 255cm. This is larger than the outer radius of the hadron calorimeter since we will not be building a cylindrical detector, but a polygonal one (current thinking is dodecagonal). The barrel composition is as follows:

This is capped with disk endplates of 6cm steel from r=250cm to 332.8cm

The field is solenoidal, constant 5 Tesla along z up to half the coil thickness and -0.6 outside.

Muon System:

The muon system is composed of 11 layers of 20cm thick Iron plates interspersed with double RPC readout.
The barrel inner radius is 338.8cm with z extent of +/- 294cm.
The endcap sits outside the barrel at an inner z of 303.3cm and radius from 20.0cm to 608.2cm

Segmentation

The readout is 3cm x 3cm squares.

An x-y quarter view of the sid02 calorimeters and solenoid can be found at sid02_Calorimeters_QuarterView.eps

Masks and Far Forward Detectors

The far forward region is designed for the 14mr beam crossing solution so has separate incoming (inner radius 1.0cm) and outgoing (inner radius 1.5cm) beampipes. The far forward plug is designed to fit within a radius of 20cm. It starts with an electromagnetic calorimeter (LumiCal) with the same composition as the endcap calorimeter, extending from 6.0cm out to 19.5cm.

The calorimeter is backed up by a conically tapered tungsten mask, inner radius 8.0cm at z of 182cm, tapering to 16cm at z of 313.5cm. The outer radius is constant at 15.5cm.

There is a far forward low-Z shield (12.39cm thick Borated polyethylene) at z of 282cm.

This is followed by a 50 layer silicon-tungsten calorimeter (BeamCal)at z of 295cm.

Segmentation

All the far forward electromagnetic calorimeters have 3.5mm x 3.5 mm square readout.

An x-y quarter view of the sid02 far forward region (also referred to as the machine-detector interface, or MDI) can be found at sid02_MDI_Cut.eps

For additional details, please see the xml file.