D. Shane Smith
Ohio State University
Outline of Talk
Introduction
Projects:
BaBar HV System
ATLAS Optoboard
Compton PET
Conclusion
Introduction
Professional Experience
6 years electronics engineering experience at
the Ohio State University physics department
B. S. E.C.E. The Ohio State University
obtained while working full time at OSU
electrical engineering specialization
B.S. E.E.T. DeVry University
Introduction
Project Overview
High Voltage Power Supply for the BABAR
Muon Detector System
Opto-Board for the ATLAS Pixel Detector
Optical Links
High Resolution PET Camera
Projects: BaBar
HV Power Supply for BaBar Muon Detector
 80 output channels per HVPS
 1.5nA current measurement resolution per channel
 per channel output protection circuitry
 4 high voltage segments (20 outputs per segment)
 individually adjustable from 0 - 6KV DC, 1V resolution
 Controlled by a Xilinx FPGA and Rabbit Microcontroller
via CANBUS or Ethernet interface
 HV rail generated by a commercial DC-DC converter
 89 O.S.U. designed printed circuit boards per HVPS
 Total of 25 HVPS boxes produced
 1/3 of the system installed at SLAC and taking data
My Role in the HVPS System Development
 Realization of system level to hardware level design
 schematic and PCB layout design
 component selection and procurement
 Designed all Xilinx FPGA firmware
 FPGA performs data collection and control signal generation
 bus interfaced to CANBUS controller and Rabbit Microcontroller
for remote control
 Supervised production of HVPS
 selected and contacted outside vendors on fabrication and assembly
of printed circuit boards
 instructed technicians on assembly techniques, soldering, testing,
and troubleshooting of all phases of HVPS production
 Periodically traveled to the Stanford Linear Accelerator
Center for installation, upgrades, and repairs
Top View
Over-Current Protection and Voltage Control
Current Measurement Module
 Per channel floating power supply and low power ADC circuit
 Floating supply referenced to output voltage
 operation at any output voltage
 floating circuitry survives unexpected output transients
 Per channel over-current protection
 per channel output voltage “self ” adjusts without disturbing other
channels within the high voltage segment
Current Measurement Module Circuit
Installation of HVPS boxes at SLAC
HVPS back panels
& HV cables to
detector
Opto-Board for the ATLAS Pixel
Detector Optical Links
 Miniature optical transceiver board
 thick film circuitry on Beryllium Oxide substrate
 14 electrical, dielectric, resistor, and mechanical layers
 Houses two O.S.U. ASICs and associated optical devices
 DORIC - Digital Optical Receiver Integrated Circuit
 VDC - VCSEL Driver Chip
 Both done in IBM .25m CMOS
 8 channel VCSEL arrays
 8 channel PIN diode array
 custom packaging developed by Taiwanese collaborators
 Opto-Board ASICs and optical components proven to
tolerate radiation doses up to 30 MRad
My Role in the Development of the Opto-Board
 Designer of all prototype and production Opto-Boards
 Produced test systems for all ASIC generations
 packaged chips
 irradiation test systems
 used LabVIEW for data acquisition
 Trained junior engineers and graduate students
 printed circuit design
 ASIC and Opto-Board operation
 LabVIEW programming
 Designed probe cards for bare die qualification
 Participated in ASIC irradiation experiments at CERN
Opto-Board Block Diagram
Opto-Board Prototypes
• Opto-RV1 (FR4)
• DMILL DORICs and VDCs
• OSU 2X VCSEL 1X PIN Arrays
• Opto-RV2 (FR4)
• DMILL DORICs and VDCs
• OSU 1X VCSEL & 3X PIN Arrays
• Opto-RV3 (FR4)
• IBM .25m DORICs and VDCs
• Taiwan 2X VCSEL 1X PIN Arrays
Opto-Board Prototypes Continued
• Opto-RV4 (FR4)
• IBM .25m DORICs and VDCs
• Taiwan 8X VCSEL &8X PIN Arrays
• Opto-BeO1 (BeO)
• IBM .25m DORICs and VDCs
• Taiwan 8X VCSEL &8X PIN Arrays
ASIC Irradiation Data Acquisition System
control room circuitry
25m
in beam circuitry
OSU ASIC
Opto-Board Irradiation Data Acquisition System
Test electronics at
OSU before trip to
CERN
25 meter optical fiber
Opto-boards
Rad hard
optical
fibers
Stage moves 25m to
reach proton beam
Production Opto-Board (BeO)
PIN Pack
VDC
VCSEL Pack
DORIC
Housing
Compton Camera Hybrid
 Low noise amplifiers attached to a 512 channel Si Pad detector
 Used in high resolution PET imaging
Energy Resolution of Photons from Technicium-99
Images of Two Point Sources
Compton PET
MicroPET R4
Source
F-18
in glass capillary tubes
5
F-18
5
4
4
1.1~1.2 mm
3
0.4 mm
3
2
2
1
1
Glass wall
0.2 mm
0
0
cm
1
2
3
4
5
0
0
cm
1
2
3
ML-EM Image reconstruction with Si-Si coincidence events
4
5
Diamond Radiation Monitors
 Radiation monitors for BABAR, Belle, CDF, ATLAS, and CMS
 Reside in high radiation regions
 Used to achieve high / safe experiment luminosity
hand crafted prototype
multi-layer alumina production model
Other Notable Experience
 CADENCE integrated circuit design software
 designed a high speed, low noise, charge sensitive amplifier in the
AMS .5m CMOS process
 HSPICE circuit simulation
 simulated commercial device models and integrated circuit designs
 Microelectronics fabrication
 familiar with repair, maintenance, and use of a Kulicke and Soffa
1460 automatic wedge wirebonder
 operated and programmed a Karl Suss AP-6 semi-automatic probe
station
Questions?
D. Shane Smith