Team Muon Critical Design Review Jennifer Nill Chelsea Donaldson Graham Risch Jonathan Lumpkin Henry Shennan October 5, 2010 Fall 2010 Rev A/B

Mission Overview The purpose of our experiment is to determine how the number of high energy particles of ionizing radiation incident on a given area in a given period of time varies with the detector’s altitude. Particles produced as a result of air showers caused by the collision of cosmic rays with atmospheric matter. Specifically detecting muons (µ - ). Control measurement provided by a ground-based detector. Secondary purpose: To determine if the difference between muon flux at maximum altitude and the simultaneous flux on the ground support the conclusion that the relativistic effect of time dilation from the observer’s reference frame results in a greater flux on the ground than the value predicted by non-relativistic parameters. Because we CAN!

Requirements Flow Down Requirements set in Class: Must be under 850g, fly a camera, contain a HOBO, etc… Requirements set by our Team: Whenever possible, the walls of the craft shall be used to provide structural support to eliminate the need for additional supports and saving weight. Donated materials shall be used wherever possible in order to decrease the cost of the experiment. Several of the larger expenses, namely the two necessary photomultiplier tubes, will be eliminated through donations. The circuit board for the detector control shall be etched by hand to eliminate the expense of professional PCB fabrication. Materials durable enough to withstand brief shock and significant, sustained vibration (as determined by testing) must be used in the construction of the aerial component. Plastic-based scintillators shall be used in lieu of the traditional glass scintillators for their better thermal properties (no reduction in performance from 0 ｰ C to -60 ｰ C) and for their durability. Onboard electronics shall be placed on foam footers to reduce the effects of mechanical shock. The craft must include a thermally insulated section where the onboard electronics and secondary mission payloads will be maintained within their reliable operating temperatures (assumed to be greater than -10 ｰ C) The scintillators shall be supported mechanically in order to maintain their separation when influenced by shock or extreme air pressure.

Requirements Flow Down Team Requirements (cont’d): A pair of scintillators shall be used to detect and determine the directionality of incident high-energy ionizing radiation. Photomultiplier tubes appended to each scintillator paddle shall allow the detector to make measurements with the sufficient sensitivity to achieve the objectives of the mission. A microcontroller and flash memory must be used to collect and record data at 5s intervals from the detector board and record that data in a format in which it can later be easily extracted for analysis. A ground-based cosmic ray detector must be either built or acquired. The two detectors must be calibrated relative to each other so that the ground-based detector may take data to act as the baseline to which measurements made at altitude may be accurately compared. The firmware of a A570IS Canon digital camera must be reprogrammed to take photographs at specific intervals for the duration of the flight.

Drawing

Functional Block Diagram

Meeting Requirements Our Balloon SAT has been designed to ascend to about 30-40km and be able to return safely without harming our payloads. We have designed our spacecraft within the requirements set by the class. Under 850g, HOBO, camera, etc..

Parts PartDescriptionManufacturerSupplierDimensionsWeightCost S1A570IS camera and accessoriesCanonGTS45x75x90mm200gN/A S2HOBO data loggerOnset Inc.GTS68x48x19mm30gN/A S3Arduino MicrocontrollerArduinoSparkfun70x53x6mm40g$25.00 P1Scintillator plates (x2) (EJ-200)Eljen Tech. 70x50x7mm60g ea.$ P2Photomultiplier tubes (x2)RCAPhys. Dept.20mm dia., 70mm long 35g ea.donated P3Light paper (thick black cardstock)genericShennan3m 3 20gN/A P4Type HS-2 Optical Cement 1ozSummers Optical N/A<5g$18.00 P5PMT Wire sockets (x2)RCAPhys. Dept.22mm dia., 5mm long 5g ea.donated P6Electronics board for detector control VariableJ.B. Saunders70x60x10mm65g$55.00 est. A1Foam BoardunknownGTS4mm, 1.3m 3 60gN/A A2Foam InsulationunknownGTS6mm, 0.8m 3 50gN/A A3Heating circuit, excl. batteriesunknownGTS10x50x50mm55gN/A A410 9V batteries (3 flight, 7 testing)DuracellMcGuckin’s48x25x15<35g flight $30.00† TCO 2 (s) (temperature testing)N/ASafeway’sN/A $5.00 † G*Cosmic Ray DetectorN/AShennan200x150x150 mm 2500g + N/A

Mass and Money Budgets The estimated cost of our experiment is $218 Our estimated weight is 755g

Schedule 10/4Scintillators and PMTs ordered for the two detectors 10/7Interface board design complete 10/8Parts arrive 10/10Boards for both detectors drawn up and simulated 10/11Scintillator Testing 10/12Boards etched and populated 10/14Boards tested independent of PMT/scintillator assembly 10/14Microcontroller compatibility testing 10/18Ground detector assembled and structure testing 10/19Testing on ground detector completed 10/20Balloon SAT assembled 10/21Functional testing on aerial Balloon SAT completed 10/24Final Product Testing 10/26Pre-Launch Inspection 10/28Mission simulation (in-class) 11/2LLR presentation and DD Rev C 11/5Weigh In and Turn in 11/06Launch Date 11/30Final Presentations due 12/4Design document Rev D due and Design Expo 12/7Hardware Turn In *Team Meetings every Sunday at 6 PM

Test Plan Whip Test Temperature Test Test for data collection integrity Effect of temp on Scintillator readings Pressure’s effect on Scintillator readings Light Leak Test Scintillator Efficiency

Test Plan Schedule DateDescription 10/11Finish Scintillator Testing 10/18Finish Structure Testing 10/21Payload Testing 10/24Final Product Testing 10/26/10Pre-Launch Inspection 10/28/10In Class Mission Simulation 11/05/10Satellite Turn In Date 11/06/10Launch Date

First Draft of Expected Results We expect to find that the higher in altitude our balloon SAT is the more cosmic rays we will detect. This is because muons decay as they travel through the atmosphere, therefore less muons make it to the ground than they do 30km.

Team Organizational Chart HenryGrahamJenJonChelsea Team Leader Scintillator Design and Testing Electronics Scintillator Design and Testing Electronics Structures Data collection Team Leader Structures and Data collection

Our Biggest Worries… Time- already had to change our entire project so we have lost a lot of time. Identifying muons rather than other particles in the atmosphere (we hope to accomplish this using multiple scintillators and looking at the charge differences). Making sure our design meets all requirements (such as internal temperature control).