DRAFT Version, under construction.

This is the version of the Silicon Detector modelled as of November, 2006, post Valencia.
The compact description of this detector in xml format can be found at http://www.lcsim.org/detectors/sid01.zip . What follows is a plain text description of the file compact.xml found in this zip file.

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

Beampipe:

The beampipe is composed of three sections: a cylindrical central tube and forward and backward conical sections.
The central tube has an inner radius of 1.2cm and a z extent of +/- 6.25cm and is made of .040cm thick Beryllium.
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.
The beam pipe has a titanium inner liner 0.0025cm thick for the central barrel section and 0.0075cm thick for the conical sections.

Vertex Detector:

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

The barrels are all 12.5cm long and are composed of .0113cm Silicon, of which the outer .002cm is sensitive.
The inner radii of the layers are:

1.46cm, 2.26cm, 3.54cm, 4.80cm, and 6.04cm

Sensors are mounted on 13.5cm long support cylinders made of 0.0065cm thick carbon fiber (25% coverage of 0.026cm thick CF).
The cylinders attach to 0.0065cm thick carbon fiber bulkheads that span 1.45cm<r<6.04cm located at |z|=6.75 cm.
The vertex detector supports are 0.0427cm thick carbon fiber cylinders that span 1.45cm<r<16.953cm located at |z|=6.78cm.

Readout electronics and the radial cabling are modeled as disks at the ends of the sensors.
At the ends of each sensor layer are G10 rings with a radial thickness of 0.2cm and a thickness in z of 0.498cm.
The rings have an inner |z| position of 6.25cm and the inner radii are the same as the sensors.
Radial cables are modeled as Cu disks with an inner |z| of 6.90cm and radial spans and thicknesses given by the following table:

There are four forward disks on either end, composed of a total of .0113cm of silicon, of which the inner .002cm is sensitive.
All of the disks extend to a maximum radius of 7.5cm.
The innner |z| positions and inner radii for the four disks are:

The forward disks are supported by 0.0065cm thick carbon fiber (25% coverage of 0.026cm thick CF) that are located 0.02cm behind the inner face of the sensors and extend from the inner disk radius to an outer radius of 16.953cm.

Forward disk readout electronics and cables are modeled as having an inner and outer part.
The inner part consists of G10 rings of 0.1cm thickness in radius and 0.2mm thickness in z that are located radially just inside the sensors and begin 0.1cm in front of the inner sensor plane.
The outer part consists of G10 rings of 0.5cm thickness in radius and 0.2mm thickness that are located radially just outside the sensors and begin 0.2cm in front of the inner sensor plane.

Cables and services are in 3 parts.
The inner cables are 0.012cm thick and run conically from an inner radius of 1.32cm at |z|=6.9cm to 1.455cm at |z|=10.0cm.
Service material of thickness 0.3cm runs conically from an inner radius of 1.455cm at |z|=10cm to 1.542cm at |z|=12cm.
The outer cables are parallel to the conical beam pipe and flare from a thickness of 0.010cm at an inner radius of 1.542cm at |z|=12cm to a thickness of 0.004cm at |z|=167.9cm.

The entire vertex detector is enclosed within a 200cm long double walled carbon fiber support tube.
The support tube walls have inner radii of 16.954cm and 18.434cm and are 0.0427cm thick.
The ends of the support tube double-walled disks of 0.0427cm thick carbon fiber disks that span 5.5cm<r<16.953cm and are located at |z|=97.5cm and |z|=99.74cm.

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| extent of the barrel silicon 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 .025cm CarbonFiber, 0.8cm of Rohacell31 and 0.025cm CarbonFiber. The inner radii and |z| extent are given by:

Endcap:

The forward disks have two sensors per layer that are slightly displaced in |z|. The table below shows the radial extant of the disks and the inner |z| position for the "A" and "B" sensor planes.

Each A plane has the following material:

where each layer is composed of double-sided sensor modules to measure coordinates in two views. The forward disk supports are composed of .039cm CarbonFiber, 1.2cm Rohacell31 and 0.039cm of CarbonFiber. The sensor modules mounted outside of the disks are double-sided and have 0.03cm of silicon mounted on either side of CarbonFiber/Rohacell31 frames that clip into PEEK (Polyetheretherketone) mounts. The average thickness of the CarbonFiber, Rohacell31 and PEEK in the modules of each disk double-layer is assumed to be the same as that for the barrel modules. The average thicknesses of the readout material are also assumed to be the same, but are repeated on both sides of the modules for double-sided readout.

The the z-positions and radial extents of the annular support rings that complete the structure of the tracker are:

These rings are composed of 0.15cm thick CarbonFiber. The readout and power distribution boards are mounted on the outside surfaces of these 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.

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

The endcap plug sits inside the barrel cylinder, so the barrel z extent is +/- 182.0cm.
The endcap starts at an inner radius of 26cm and extends out to 126.5cm.

Segmentation

The readout is 3.5mm square cells.

Hadron calorimeter:

The hadron calorimeter is a sampling calorimeter composed of 34 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 +/- 277.2cm.
The endcap extends from an inner radius of 26.0 cm to an outer radius of 140.75, inner z of 182.0.

Segmentation

The readout is 1cm squares.

Solenoid:

The solenoid is modelled as a cylinder with an inner radius of 250cm. 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 octagonal). The barrel composition is as follows:

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

Muon System:

The muon system is implemented as a sampling calorimeter composed of 48 layers of:

The barrel inner radius is 333.0cm with z extent of +/- 277cm.
The endcap sits outside the barrel at an inner z of 277.5cm and radius from 26.0cm to 645.0cm

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

Segmentation

The readout is 3cm squares.

Masks and Far Forward Detectors

This detector is designed for the 2mr beam crossing solution. The far forward plug extends out to
a radius of 25cm. It starts with an electromagnetic calorimeter with the same composition as the
endcap calorimeter, extending from 8.68cm out to 25cm.

The calorimeter is backed up by a conically tapered tungsten mask, inner radius 8.68 at z of 182cm,
tapering to 16cm at z of 330cm. The outer radius is constant at 25cm.

There is a far forward low-Z shield (10cm thick Beryllium) at z of 285cm, with a 1.5 cm central aperture.

This is followed by a 50 layer silicon-tungsten calorimeter at z of 295cm, with a single aperture for
both the incoming and outgoing beams, radius 2cm.

Segmentation

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