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Cosmic Ray Research. Alex Souvannakhot & Sisi Srisutiva. Overview. This experiment aims to study the relationship between high energy particles and the radio waves they produce. The radio waves will provide a better picture of the primary particles. What are cosmic rays?.
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Cosmic Ray Research Alex Souvannakhot & Sisi Srisutiva
Overview This experiment aims to study the relationship between high energy particles and the radio waves they produce. The radio waves will provide a better picture of the primary particles.
What are cosmic rays? High energy particles from deep space are bombarding the atmosphere creating a shower of particles. μ → e− + Ve + Vμ
Cosmic Ray Detectors • Consists of a scintillator and a photomultiplier tube • These connect to a data acquisition (DAQ) board which screens the data and records hits which can be read through a terminal emulator in Windows • Since our overall goal is to trigger the oscilloscope when the detector sees a coincidence and our trial of Hyperterminal expired, we bypassed the DAQ through the NIM setup • NIM units had to be adjusted to mimic DAQ board • .300V threshold
Calibration of CRDs • CRDs require plateauing to achieve optimal operating voltage • A signal must exceed the threshold value of .300V to be counted. • Plateauing adjusts the voltage to each PMT • Higher voltage means higher sensitivity to hits • Aiming to find the optimum voltage where the PMT is sensitive enough to pick up cosmic ray hits but not excess noise
To Plateau • Set a reference channel while all other channels are turned to the minimum voltage • Adjust the voltage of another channel until the graph of number of coincidences vs the channel voltage plateaus and begins to separate from the graph of the single hits • Repeat for other 3 channels
Displacement Study • To verify that our detectors were working and plateaued correctly, we used a displacement study. • Limits the angles of incoming cosmic rays that can hit the detectors
Nuclear Electronics • NIM- Nuclear Instrumentation Modules • BNC- Bayonet Neill- Concelman • LEMO-name of producer • NIM standard allows for flexibility of interchanging of instruments. • Process fast pulse- up to nanoseconds • CAMAC and VMEbus
NIM Rig • CRD • Quad Discriminator • Coincidence Unit • Oscilloscope • Antenna
Discriminator • Once the amplitude exceeds the threshold - 300 mV-, a standardized NIM pulse will be sent out.
Timing Diagram • The signal will experience delay as it passes through the cables and modules • The delay must be known to find the timestamp of the event(coincidence)
Cable Delay • We used a formula to predict the cable delay and verified with a scope. • ε = insulation dielectric constant
Oscilloscope and Antenna • The oscilloscope is programmed to collect data from the antenna when a pulse from the coincidence unit passes the threshold.
Results Results will be coming shortly. We will be testing to see if we can collect valid data in a farm on the outskirts of Lawrence.
Problems Encountered • Light leaks • Background noise picked up • Broken power sources • Lack of manuals of NIM • Programming the oscilloscope • Expiration of HyperTerminal trial
Improvements • Use a radioactive source, such as a 60Co source, to sweep the CRDs during calibration. • Create a better and sturdier detector holder.
Works Cited Weinberg, Matthew. "Measurement of the Decoherence Curve of Cosmic Ray Muons Using Silicon Photomultipliers." Thesis. University of Minnesota, 2008. Web. 20 July 2012. <http://mxp.physics.umn.edu/s08/Projects/S08_SiMultipliers/mweinberg.pdf> Cable Delay Formula. Digital image. Digi Key. N.p., n.d. Web. 20 July 2012. <http://www.digikey.com/Web%20Export/Supplier%20Content/GenCable_42/PDF/GC_CableDesignEquationsCoaxialCable.pdf?redirected=1> Blanco, F. Educational Cosmic Ray Experiments with Geiger Counters. University of Catania, n.d. Web. 20 July 2012. <http://arxiv.org/ftp/physics/papers/0701/0701015.pdf>. Cable Delay Formula. Digital image. Digi Key. N.p., n.d. Web. 20 July 2012. <http://www.digikey.com/Web%20Export/Supplier%20Content/GenCable_42/PDF/GC_CableDesignEquationsCoaxialCable.pdf?redirected=1>. Hong, Yung M. "MUON'S LIFE TIME MEASUREMENT AND HIGH ENERGY COSMIC RAYS SIMULATION." Summer Undergraduate Research Exchange Program (SURE). N.p., n.d. Web. 20 July 2012. <http://www.phy.cuhk.edu.hk/sure/comments_2001/yung_paper.html>. Karn, Peter. "The Kake Cosmic Ray Telescope." N.p., n.d. Web. 20 July 2012. <http://mxp.physics.umn.edu/s07/Projects/S07_CosmicRaysDistribution/index_files/page0003.htm>. "Scintillator." Wikipedia. Wikimedia Foundation, 19 July 2012. Web. 20 July 2012. <http://en.wikipedia.org/wiki/Scintillator>. Weinberg, Matthew. "Measurement of the Decoherence Curve of Cosmic Ray Muons Using Silicon Photomultipliers." Thesis. University of Minnesota, 2008. Web. 20 July 2012. <http://mxp.physics.umn.edu/s08/Projects/S08_SiMultipliers/mweinberg.pdf>. .
QUESTIONS? READ THE MANUAL!!!!11one
Acknowledgements Without the help of the following, we would not achieve the same level of success: • Prof. Dave Besson • Kate Orr • Bob Peterson • Google