Characterization and Applications of Hybrid CMOS Detectors in X-ray Astronomy

Open Access
Author:
Bongiorno, Stephen Dominick
Graduate Program:
Astronomy and Astrophysics
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
April 30, 2013
Committee Members:
  • Abraham David Falcone, Dissertation Advisor
  • David Nelson Burrows, Committee Member
  • Stephane Coutu, Committee Member
  • Lawrence William Ramsey, Committee Member
  • Michael Eracleous, Committee Member
Keywords:
  • X-ray
  • Instrument
  • High-Energy Astrophysics
  • CMOS
  • Active Pixel Sensor
  • Hybrid CMOS Device
Abstract:
The hybrid CMOS detector (HCD) is a powerful focal plane array (FPA) architecture that has begun to benefit the visible-infrared astronomical community and is poised to do the same for X-ray astronomy. Since Servicing Mission 4 in 2009, an HCD has given the Hubble Space Telescope's Wide-field Camera 3 improved imaging capability in the near-infrared. HCDs have been specified to operate at the focal plane of every science instrument on board the James Webb Space Telescope. A major goal of the Penn State X-ray Detector Group has been to modify the flexible HCD architecture to create high performance X-ray detectors that will achieve the currently unmet FPA requirements set by next-generation telescopes. These devices already exceed the radiation hardness, micrometeoroid tolerance, and high speed noise characteristics of current-generation X-ray charge coupled devices (CCDs), and they are on track to make a breakthrough in high count rate performance. This dissertation will begin with a presentation of background material on the detection of X-rays with semiconductor devices. The physics relevant to photon detection will be discussed and a review of the detector development history that led to the current state of the art will be presented. Next, details of the HCDs that our group has developed will be presented, followed by noise, energy resolution, and interpixel capacitance measurements of these detectors. A large part of my work over the past several years has consisted of designing, building, and carrying out tests with a laboratory apparatus that measures the quantum efficiency of HCDs. Details of this design process as well as the successful measurements that resulted will be presented. The topic of discussion will then broaden to the HCD's current and future roles in X-ray astronomy. The dissertation will close with the presentation of a successful project that used Swift XRT data to confirm the binary nature of the TeV emitting object HESS J0632+057, making it one of five confirmed TeV high mass X-ray binaries.