1. Background Concept Results Conclusions
Simulating a Detector at a Future Electron Ion Collider
Akshath Wikramanayake
Faculty Advisor(s): Dr. Marcus Hohlmann, Dept. of Aerospace, Physics, and Space Sciences, Florida Institute of Technology
Background
The electron Ion collider (EIC) is a proposed particle collider that is to be built in the united states. One proposed detector to be used at the EIC is the Brookhaven eA Solenoidal Tracker (BeAST), which is currently being designed by the Brookhaven National Laboratory (BNL). In order to study the performance of the detector, BNL has released the EicRoot framework, which can be used to simulate detectors.
Concept
The BeAST detector is still in its design phase, and there are several proposed changes that could either benefit the resolution of the detector or reduce the cost of assembly. If the detector could be made to operate with a 1.5 Tesla magnetic field instead of the proposed 3 Tesla field, a solenoid from an existing detector could be reused. It has been hypothesized that an additional set of Gas Electron Multiplier (GEM) trackers in the far forward region of the detector could partially offset the resolution penalty associated with the weaker magnetic field.
In order to test this, EicRoot was used to create a partial model of the BeAST detector (figure 1), and the performance of the detector with and without these additional outer GEMs (figure 2 - bottom) was compared. The comparisons were made with simulated particles with pseudorapidities ranging from η = to η = 3.131, and momentums ranging from 2 GeV/c to 60 GeV/c
Results
The tests suggest that the far forward GEMs provide a significant improvement to momentum resolution for particles with pseudorapidities in the range
1.15 < η < 3.13 with the weaker 1.5 Tesla magnetic field. The improvement is also most pronounced for particles with momentums near either end of the tested range (2 – 60 GeV/c).
Magnet yoke
e/m calorimeters
RICH detectors
3T Solenoid Cryostat
Silicon trackers
hadrons
electrons
GEM trackers
MicroMegas barrels
Time Projection Chamber
Hadronic calorimeters
Figure 1: The proposed geometry of the BeAST detector
Conclusions
Since the momentum resolution of the detector is lowest for particles with high pseudorapidities and high momentums, the results suggest the outer GEMs will be a worthwhile addition to the BeAST detector. With the outer GEMs included, it is believed the momentum resolution of the detector can be brought down to the desired 1% range after the remaining detector components are added, even with the weaker 1.5T field.
The next step is to conduct these tests for all combinations of pseudorapidity and momentum. The correlation between the momentum resolution distribution and the number of detector hits will be studied to prove the statistical significance of these results. Furthermore, the simulation model will be updated to include the remaining components and any future design changes. Finally, EicRoot will be upgraded to include position resolution tracking.
Figure 2: The simulated detector as seen in EicRoot
Top: The current working detector geometry
Bottom: Partial geometry with and without outer GEMs