pop danny zhuang. laser fiber stretcher sensor photodiode amplifier split pxi-6221 pxi-6133 pxi-6221...
TRANSCRIPT
POP
Danny Zhuang
LASER
FIBER STRETCHER
SENSOR
PHOTODIODE
AMPLIFIER
SPLIT
PXI-6221
PXI-6133
PXI-6221
RECOMBINEINTERFEREDBEAMS
FEEDBACK LOOP TO INPUT TO FIBER STRETCHER
CONVERTS LIGHT INTO VOLTAGE
SENSES DARK MATTER BUBBLE POPS
DISPLACES TO FIX THE PHASE DIFFERENCE BETWEEN THETWO BEAMS
RECORDS DM BUBBLE POPS
RECORDS IFPHASE
Life with LabView Text Based Programmer Week and a half
learning Began coding, learned
as I went ActiveX controls,
DAQmx Functions LabView source is very
messy (spaghetti code) Powerful GUI’s Excellent debugger
COUPP COUPP (Chicagoland Observatory for Underground Particle
Physics) 60 kg bubble chamber underground to avoid cosmic rays Works to detect Dark Matter; can detect Gamma rays,
neutrinos, muons, alpha, WIMPs, etc CF3I(Trifluoroiodomethane) sensitive to both spin-dependent
and spin-independent WIMP interactions Ideal temperature for each particle detection
Muon WIMPNeutron(s)
60°C 40°C40°C
SNOLAB Underground
physics Laboratory in Ontario, Canada (2km)
Specializes in neutrino and DM physics
Located in Vale Creighton Mine (Active Mine)
S- SudburyN- NeutrinoO- Observatory
The Job Highly sensitive
microphone Neutron vs. WIMP Neutron single scatter
sounds exactly like WIMP Multiple neutron scatter
is distinguishable Acoustic signature
differentiates Dark Matter nucleation
has a much higher acoustic sound
WIMP’s Weakly Interactive Massive Particles Could comprise of most if not all DM in
the universe React with weak force and gravity, no
electromagnetism, difficult to see, no strong force so do not react well with atomic nuclei
Shares properties with neutrinos except large mass thus slower and cold
Dark Matter
Matter inferred to exist because of gravitational effects on visible matter
Neither emits nor scatters light or other EM radiation
Would account for discrepancies between calculations of the mass of galaxies
So Why…
What we know about the world makes up only 4% of the universe
The other 96% is divided into two parts, Dark Energy and Dark Matter
The Old Bubble Chamber Charged Magnetic
field Particle Detector Particles
influenced by magnetic field
COUPP’s Bubble Chambers Revived technology of
particle physics Used to detect WIMPs Filled with superheated fluid
(CF3I) Depositing a small amount
of energy can nucleate the formation of an easily visible bubble
Effectively blind to the largest category of backgrounds
Progress in rejecting alpha recoils by using acoustic signature of bubble formation
When DM Passes Note: WIMP’s rarely interact with ordinary matter1. DM particle passes through bubble chamber2. Collides with a nuclei3. Elastic scatter, energy released4. Triggers evaporation of small amount of CF3I 5. Resulting bubble grows6. Digital cameras catch the process once bubble
reaches 1 mm in size7. Data stored for analysis However, the previous acoustic sensors were giving
off background radiation themselves, turned towards interferometry
Interferometry Family of techniques in which
electromagnetic waves are superimposed (place over) in order to extract information about the waves
Used in the fields of astronomy, fiber optics, engineering metrology, optical metrology, oceanography, seismology, quantum mechanics, nuclear/particle physics, plasma physics, remote sensing, and bimolecular interactions
Interferometers
Single beam is split them combined, halves travel different routes
Amplitude Splitting- primary wave is divided into two segments which travel different paths before recombining
Separate waves are combined to show some meaningful property that is diagnostic of the original state of the waves (superposition)
Routes cause a phase difference between the initially identical waves because of the unequal distances traveled by each beam
Quality of the interferometer depends on the positions of the mirrors being precisely stable
Interferometers cont’d 2 waves of same frequency combine and
result is determined by phase difference, decides constructive or destructive interference
1 crest 1 trough destructive interference (cancel)
2 crests constructive interference (add) Resulting total light field’s amplitude is sum of
amplitudes of superimposed beams Interference fringe- bands caused by beams of
light that are in phase or out of phase with one another
The Interferometer’s Role Interferometer-
instrument used to measure waves through interference patterns
Closed Laser, laser travels through optical fibers, laser couplers
Fibers detect the characteristic acoustic sound of a DM bubble nucleation
InterferenceTwo or more light beams superimposed•Spatial and temporal overlap of the two light fields•Coherence (fixed phase relationship between the electric field values at different locations or at different times) of the two light fields•Spatial coherence- a strong correlation (fixed phase relationship) between the electric fields at different locations across the beam profile, similar amplitudes•Temporal coherence means a strong correlation between the electric fields at one location but different times, tells how monochromatic a source is or how well it can interfere with itself
Astronomical Interferometry
Interferometers are ubiquitous
VLA (Very Large Array)- 27 telescopes giving 351 independent baselines at once, radio array
Mach-Zehnder Interferometer Used to determine relative phase
shift between two nearly parallel beams from a coherent light source
High coherence light from laser is split into reference and sensor arm then recombined
Photodetector measures combined light intensity
External influence (noise)
fiber couplers Instead of beamsplitters and fibersInstead of open source
Intro to Fiber Optics Optical fiber- thin, flexible fiber that acts as
a waveguide, transmitting light between the two ends of the fiber
Also used for illumination, wrapped in bundles
Immune to EM interference light goes through with few hindrances
compared to electrical cables (better) Wavelength division multiplexing (WDM)-
each fiber can carry many independent channels with light of different wavelengths
Multimode fibers- fibers that support many waves, efficient, cheaper
Single mode fibers- fibers that support a single wave, few hindrances
Good sensors for strain, temperature, pressure (DM sensor)
Laser Basics Laser emit amplified light
(electromagnetic radiation) with high spatial and temporal coherence
At higher temperatures, more current is needed to get the same power
Cold = more power Window between effective
output current and breaching max operating current is slim
Diode- semiconductor with 2 terminals, flows one way
Hardware: Building the Interferometer
Wavelength stabilized single mode fiber coupled laser diode 5mW of 1300nm
(wavelength) -infrared Low threshold current
and high slope efficiency
Operating temperature range: -40ºC 50ºC
Built-in monitor photodiode, thermo-electric cooler, and thermistor
LASER
SPLIT
Optiphase PZ1 Fiber wound piezoelectric element (transfers
electrical to mechanical) Takes in voltage, displaces the optical fiber to
get rid of phase differences between 2 beams High-speed fiber stretcher
Sensor
Optical Fibers Picks up noise
LASER
FIBER STRETCHER
SENSOR
SPLIT RECOMBINEINTERFEREDBEAMS
SENSES DARK MATTER BUBBLE POPS
DISPLACES TO FIX THE PHASE DIFFERENCE BETWEEN THETWO BEAMS
InGaAs Fixed Gain Detector Used to convert
light into voltage 700-1800 nm
(infrared) 150 MHz BW Amplified
photodetector
LASER
FIBER STRETCHER
SENSOR
PHOTODIODE
SPLIT RECOMBINEINTERFEREDBEAMS
CONVERTS LIGHT INTO VOLTAGE
SENSES DARK MATTER BUBBLE POPS
DISPLACES TO FIX THE PHASE DIFFERENCE BETWEEN THETWO BEAMS
T-Cube Laser Diode Controller
T-Cube TEC Controller
PXI-6221 Capable of both Analog
Input and Analog Output (ideal for the feedback loop to the Fiber Stretcher)
Slower than 6133 (250k samples per second)
PXI-6133 Only Capable of
Analog Input 10 times faster
than 6221 (2.5M samples per second)
LASER
FIBER STRETCHER
SENSOR
PHOTODIODE
AMPLIFIER
SPLIT
PXI-6133
PXI-6221
RECOMBINEINTERFEREDBEAMS
CONVERTS LIGHT INTO VOLTAGE
SENSES DARK MATTER BUBBLE POPS
DISPLACES TO FIX THE PHASE DIFFERENCE BETWEEN THETWO BEAMS
RECORDS DM BUBBLE POPS
RECORDS IFPHASE
PID Controller Proportional-Integral-Derivative (PID) control is the most
common control algorithm used in industry and has been universally accepted in industrial control
generic control loop feedback mechanism used in industrial control systems
Attempts to minimize error by adjusting process control inputs
PID feedback loop fixes the phase difference between the two beams and keeps the ideal fringe (light/dark; constructive/destructive)
PID Controls P- Proportional (Kp) I- Integral (Ki) D- Derivative (Kd)
The “Car” Analogy A car’s cruise
control is a PID Controller
PID Theory P Response- determines ratio of output
response to error signal controls the speed of the control system response depends on error (set point – process variable) can cause process variable to oscillate and system to
become unstable I Response- sums error over time (past error)
increases more as the error term increases D Response- predicts future error
causes output to decrease if process variable is increasing rapidly
increases with rate of change very sensitive to noise
PID Equation
U(t) = controller output MV(t)= manipulated variable Kp= proportional gain, constant Ki = Integral gain, constant Kd = Derivative gain, constant E = error (Set Point – Process Variable) T = Time
Terminology
LASER
FIBER STRETCHER
SENSOR
PHOTODIODE
AMPLIFIER
SPLIT
PXI-6221
PXI-6133
PXI-6221
RECOMBINEINTERFEREDBEAMS
FEEDBACK LOOP TO INPUT TO FIBER STRETCHER
CONVERTS LIGHT INTO VOLTAGE
SENSES DARK MATTER BUBBLE POPS
DISPLACES TO FIX THE PHASE DIFFERENCE BETWEEN THETWO BEAMS
RECORDS DM BUBBLE POPS
RECORDS IFPHASE
School
Applied science jumpstart to career and prepare for the real world
Principles and the laws of science are applicable to many things
Ability to do specialized and targeted research goes a long way
Computer Programming Awareness Growing industry Useful in almost
any job field In high demand Creativity FUN
To the Next Group of Victims and Scientists
VI readme for all programs My deepest regrets Advice document listing useful
tutorials, articles, websites, etc. My programs
Special Thanks Jeter Hall- Mentor, teacher, and
companion Supervisors Julia Dawson & Fritz
Dejongh