The Design of a Detector for the Electron Relativistic Heavy Ion ColliderAnders Ingo Kirleis1, William Foreman1, Elke-Caroline Aschenauer2, and Matthew Lamont2

1 SUNY at Stony Brook, Stony Brook NY 11790 & 2Physics Department, Brookhaven National Laboratory, Upton, NY 11973

August 2009

CalorimetryA calorimeter in particle physics is a device which measures the energy of particles. When particles enter the calorimeter, a particle shower occurs at which time the energy is collected and analyzed. An electromagnetic calorimeter is one specifically designed to measure the energy of particles that interact via the electromagnetic interaction, i.e. , while a hadronic calorimeter is one designed to measure particles that interact via the strong nuclear force. Below we see the preliminary calorimeter design by itself. The electromagnetic calorimeter can be seen in blue and the hadronic calorimeter in green.

MagnetsOur design calls for a solenoid and two dipole magnets. The solenoid consists of wire coils wrapped around an iron core which, when an electric current passes through, produces an electric field of strength 4 T. Its main purpose is to bend the particles in the detector. Their momentum is determined from their curvature. The solenoid is shown below in red in the barrel. The dipole magnet creates a homogeneous magnetic field over some distance. It's purpose is to twofold: on one hand it is integrated in the accelerator to bend the particles so they collide in the detector and it is needed to detect low momentum particles from the collision. The dipole magnets are seen below in violet in the forward and rear regions.

Particle IdentificationOur design has a Detector of Internally Reflected Cerenkov light (DIRC), a High Threshold Cerenkov Counter(HTCC), and a Ring Imaging Cerenkov Counter (RICH). A DIRC can separate pions, kaons and protons up to 4 GeV with high efficiency. It can be seen below in blue in the barrel region. The main function of the HTCC is to aid in the identification of electrons. It uses CO2 as a radiator providing a high threshold such that will cause electrons to emit Cerenkov light. The HTCC can be seen below in red in the forward region. The RICH is filled with C4F10 gas combined with aerogel which will help to separate pions, kaons, and protons from each other. It can be seen below in green in the rear region.

Tracking

Results: Full DesignBelow we see all components together in the first ever electron relativistic

heavy ion collider design using GEANT.

Abstract Preliminary Design

Proposed Location OutlookFrom this point, steps can be taken to further develop the design of the detector. Magnetic fields and materials must be defined in the GEANT language where, once implemented, will allow scientists to more realistically simulate, what is happening during a collision using PYTHIA visually along with the three dimensional design view. GEANT simulates the detector response, a crucial element in allowing for excellent further analysis.

AcknowledgementsMatthew Lamont

Elke-Caroline AschenauerAbhay Deshpande

Pavel NevskiThomas Ullrich

The EIC Task ForceMelvyn Morris and the OEP Staff

Steven VigdorSamuel Aronson

We will have several tracking detectors which will allow us to determine the momentum and position of the outgoing hadrons and leptons. These tracking devices can be seen below outlined in black. The Central vertex tracking detector can be seen in the barrel region as it is encased in a yellow tube. It consists of a jet type drift chamber. Particle tracking at small forward and backward angles to the beam is done with planar drift chambers. The decays of short lived particles can be detected in a vertex detector which has a time-expansion type drift cell structure. For reference purposes the interaction point can be seen as a red star in the barrel region.

Background Photo: Google Earth