Quarknet 2011:Students:

N.Tarshish, S. McNamara, B.

Goldblatt, P. Suganthan Teachers:

M. Baron, S. PolgarNote: some graphics taken from 2008 Quarknet site

What does CREAM Stand for?Cosmic

Ray Exposed Acquisition system of Muon track data that is later interpreted and analyzed at Quarknet 2011, a summer program for high school students at UPENN.

GoalsSet up hardware so that

cosmic rays trigger scintillators and detect the rays’ paths through chambers, which contain sets of 32 proportional drift tubes

Create a program to analyze data from the drift tubes

Determine, graph, and store equations of the muon tracks.

Muon Tracking Process Abbreviated

Primary cosmic ray strikes Earth’s atmosphere SAD PUTIN

Capturing The Cosmic Track

INVERSE CIA/KGB RELATIONSHIP

SAD PUTIN

Primary cosmic ray strikes Earth’s atmosphere

The Apparatus

Scintillators

Photomultiplier Tubes

ScintillatorsThe scintillators’ signals are sent first to the discriminator The scintillators’ signals are sent first to the discriminator and then to the logic unit. If the logic unit finds a and then to the logic unit. If the logic unit finds a coincidence, it sends a trigger signal to the Xilinx chips. coincidence, it sends a trigger signal to the Xilinx chips. Upon receiving a trigger signal, the Verilog captures data Upon receiving a trigger signal, the Verilog captures data from the proportional drift tubes. from the proportional drift tubes. Problems:Problems:

Checking for light leaksChecking for light leaksFinding the optimal running voltagesFinding the optimal running voltagesMaking sure we received coincident signalsMaking sure we received coincident signals

At the beginning of the project, we swept through At the beginning of the project, we swept through different voltages in order to find a voltage, at which we different voltages in order to find a voltage, at which we could be confident that we were detecting the presence could be confident that we were detecting the presence of muons and not noise interference.of muons and not noise interference.

Midway through the program, the top scintillator began Midway through the program, the top scintillator began reporting thousands of more events per second than reporting thousands of more events per second than was expected. This impelled us to identify a new was expected. This impelled us to identify a new voltage that yielded stable results.voltage that yielded stable results.

Proportional Drift Tubes

Photo Drift Tubes (PDTs) detected muons and sent signals to the ASD-Q and Xilinx chips

Problems: Finding the optimal

running voltages for the tubes

Getting a proper ground to reduce noise

Finding broken tubes and documenting malfunctions

Several of the tubes were not connected to the ASD chips and many of the connections needed to be fixed.

A handful of constantly firing tubes needed to be grounded.

Thresholds had to be re-established after the faulty tubes were removed.

In the end, since we had too many faulty tubes in chambers one and two and not enough time to fix them, the two chambers had to be abandoned.

Drift Tube Problems

ASD-Q Chip

This chip amplified, shaped, and discriminated “raw” signals from the drift tubes. These signals were then sent to the Verilog program in the Xilinx chip.

Problems:Reducing noise

through making better grounds

Finding the optimal threshold for the chips

Verilog/Labview/JavaWe inherited past years’ Labview and Verilog

programs. Slight modifications were made to the Verilog

program to correct a few errors in the code. Isaac also threw together a Java program to

convert Labview’s unstructured hex output into a structured decimal data file. Nathaniel and Ben further developed the program to match the C++ program’s needs.

C++ Program A major component of this

year’s project was the development of a program to analyze the data

C++ was selected because it was the only language that Nathaniel was familiar with.

The program takes in the Java program’s data txt file and outputs the graphs of the muons and the respective time circles that the track is tangent to.

The program successfully identifies tracks, but defines a limited solid angle. Therefore, only a small subset of the data matches the parameters set by the program.

Also, the program currently finds the path of the muon in only two dimensions due to the lack of functional tubes in the ZY plane.

Data Analysis Mathematics We developed a

method for finding a generalized common tangent line for any four possible timing circles. We had to design the mathematical solutions so that they were programmable.

We learned much about the subtleties and faults of our system during this stage of the project.

Final AnalysisOver the last few days, we

have been collecting data. Unfortunately, the majority of the events involved fewer than four tubes firing and therefore the C++ program was not applicable.

Some of the events involving three or more tubes appeared to be useable. While the coincidence times did not fit our expectations, the geometry of the tubes registering the events did.

Future Quarknet Goals Identify and fix all problematic

tubesIncrease solid angleGenerate a 3-dimensional

graph of the muon pathsCreate other data analysis

programs, which are based on tube firing frequency, the statistical distribution of the tracks, etc.

Begin running gas through the tubes and set up hardware as soon as possible

Other Unrelated DiscoveriesParticle accelerator or Death Star weapon?

Steve sleeps in various positions :

Highlights“So why do they pay for this?” – Ben

Goldblatt, asking Professor Williams mid-talk. “Look! I put the faculty to sleep!” – Professor

Devlin after noticing Mr. Polgar sleeping during his lecture. He then proceeded to shine the laser pointer on Mr. Polgar’s belly.

“I have this incredible urge to feel Rick’s beard.”- Anonymous

Polgart – the concoction of yogurt-drowned un-identifiable breakfast foods that Mr. Polgar daily consumes.