Transcript NIMROD’s GUI - Texas A&M University

The development of the NIMISiS
Bias Control GUI
by Christopher Crane
Mentor Dr. Sherry Yennello
Outline
Overview of intermediate energy physics
Why use NIMROD?
NIMROD upgrade
What is a silicon detector and a photodiode
detector?
What is a bias box?
Previous methods of setting channels and
why use a graphical user interface?
Connecting NIMROD and Summary
Intermediate Energy Physics
Different kinds of particles and the necessity for
different kinds of particle detectors
From fragment yields at intermediate energies
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From isobaric ratios
We can learn about temperature
The asymmetry term in the equation of state*
2
E B (Mev)  av A  as A 3  Ac
Z2
A
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Get isotopic distributions
Phase transition
1
3
( N  Z )2
 asym
A
Why Use NIMROD?
NIMROD consists of telescopes and super
telescopes.
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A telescope consists of a gas detector, a silicon detector,
and a cesium iodide detector.
A super telescope consists of a gas detector, two silicon
detectors, and a cesium iodide detector.
These are arranged in a 4π or spherical
arrangement.
This is good for central, intermediate energy
collisions. It is also efficient at detecting heavy
residues.
Super Telescope Detector
NIMROD Picture
Upgrade of NIMROD
Additional silicon detectors are being
added in the forward beam direction to
NIMROD
The addition consists of an additional ring
from 45 to 90 degrees and a half sphere
from the ISiS array.
The ISiS array also consists of telescopes
(gas detector, silicon detector, and cesium
iodide detector)
ISiS
Silicon Detectors
Silicon detectors are a PN junction.
The detectors need an electrical voltage to
be applied in order to create a layer of
depletion at the junction.
Why depletion is important?
What is leakage current?
As Radiation bombards these silicon
detectors it becomes harder and harder to
maintain the depletion layer.
Photodiode Detector
A silicon wafer that is used to capture light
signals produced by radiation in cesium
iodide detectors
This are used to collect the signals from
the cesium iodide detectors of ISiS
What is a Bias Box?
Delivers positive or negative voltage.
between 0-255 volts
It can control up to 320 channels at one
time
Can monitor leakage current and actual
voltage on a silicon or photodiode type
detector
Bias Box
Previous History
All silicon detectors have either there own
individual high voltage supply modules or
they were controlled by a box which set
multiple silicon but each silicon had to be
set by hand or “dialed up”.
It also monitored leakage current but an
experimentalists had to be inside the cave
to monitor the values, which means loss of
beam time about ($750/hr).
Why make a Bias Box GUI?
We need to be able to remotely
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Bias all channels at once
Set all channels to zero at once
Bias a single silicon
Monitor the voltages and leakage currents
Load voltages from a file and save voltages to
file
Change a voltage array file conveniently
Automatically ramp the voltage up and down
The Bias Box GUI
Bias Box GUI Picture #2
Bias Box GUI Picture #3
Connecting the components
The Bias Box
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To add voltage to the silicon through the controller board
Connect to an Analog to Digital Converter (ADC) for monitoring
the voltages and currents.
The Controller Board
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The NIMROD silicon detector is managed by a controller board
on the outside of the ring.
The controller board delivers voltage to the silicon.
It pre-amplifies the analog signals produced by the silicon.
Then passes the amplified signal to another amplifier
Path of The Signal
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After the amplifier the signal then goes to an ADC which passes
the signal to the computer
Afterwards a graph is produced from the energy loss between
the ion chamber and the silicon; from which particle identification
can be done.
Controller Board
Summary
User Interface program was designed with the
intent of monitoring voltage and current while
biasing to NIMROD’s detectors remotely,
including the new addition of ISiS, a spherical
particle detector.
The program takes user input values and sends
Biasing voltages to NIMROD’s silicon detectors.
The GUI also monitors the actual charge held in
the detectors of a specified silicon, and the
leakage current on a specific silicon.
Acknowledgements
The National Science Foundation
The Department of Energy
SJY Group
Dr. Sherry Yennello, Sara Wuenschel, August Keksis,
Zach Kohley, Brian Stein, Sarah Soisson, George
Souliotis, and Dinesh Shetty.
Thank You for your attention
Thank You REU Program at Texas A & M
University