e-Lab Fellows Working Documents
1. PLATEAUING DETECTORS
"6000" CRMD Counters, Current version: Nov 2011
Remade from previous versions; tested by Jeremy Paschke and Martin Shaffer, Summer 2009
Students will require both following files to plateau.
Older, out-of-date versions:
From Jeremy Paschke, Summer 2008
These two documents include edits and remakes of Fellows documents listed above. Fixes fundamental errors. Thanks to Jeremy. Fellows, please review and add edits. When all changes have been received, these will be moved into the Cosmic e-Lab proper for public use.
HOWTO Plateauing Powerpoint: How-to-Plateau-2008JP
Plateauing Spreadsheet Form: Plateau-Template-2008JP
- From Fellows, Summer 2007
We've got a nice powerpoint on connecting all the equipment and plateauing the counters. The level is intended for beginning students or teachers and is designed to march through the procedure as time efficiently as possible, so that anyone can start to do real science asap.
HOWTO Plateauing Powerpoint: How+to+Plateau
There's an excel spreadsheet template associated with these directions. The powerpoint has a link to the spreadsheet, but you may have to open it by yourself if you download from here.
Plateauing Spreadsheet Form: Plateau+Template
- For completeness; plateauing instructions contributed from others; some out of date
Notre Dame: Counter_efficiency_ND.doc
Mark Adams, UIC: MAdamsRevised_plateau.doc
"5000" series Cookbook; out of date: Plateau_cookbook.doc
2. RUNNING A WORKSHOP
This file was made during the leadership session at Fermi Lab on Sunday, 7/15. Please improve and delete this disclaimer.
This file is the one created by Cheryl and her group during the workshop.
3. PLANNING AN EXPERIMENT
This is an Excel spreadsheet template for calculating how long you might need to run an experiment to see statistically significant differences in count rates.
You enter your expected baseline count rate, and your expected difference between counts under different conditions. The ss calculates total counts during increasing numbers of seconds, and the uncertainty in that total count number. As you'll see, the smaller the expected difference, the more counts you need to collect, and the longer the detector needs to run.
We used this for an experiment in a 15 story steel & concrete building. We used 2 counters set to count when a 2 way coincidence occurred. The counters were separated by about 60 cm vertical distance. We planned to take counts on the 15th floor, 8th floor, and the basement. We expected, based on just a hunch, that the building would have very little effect on counts. We decided to take enough counts to demonstrate a real difference at a 1% level. This spreadsheet would calculate about an hour of counting time to collect enough counts to prove a difference at a 1% level.
By the way, the actual difference was about a 2/3 reduction in counts as the detector moved from top to bottom of the building.
Here's the Excel spreadsheet for planning an experiment: Planning an Experiment
4. BLESSING PROPOSAL DISCUSSION
Proposal for Blessing data, July 2007.
Article from Auger group on Blessing data.
5. ESTIMATING FLUX RATES
Muon Flux rates are strongly affected by: Scintillator surface area Orientation Spacing and solid angle acceptance Intervening absorber material and thickness Altitude
A simple model is presented to allow estimating flux rates due to area, spacing, and absorber.
If you would like to know more about how this functions you may want to read the following notes.
This model uses the following rules-of-thumb: Sea Level muon spectrum is flat with a slope of dN/dE = 0.004/(GeV cm2 s sr) Energy absorption is proportional to "range" X = density x thickness. This has units of g/cm2 or since water has a density of 1 g/cm3, one can use the unit of "cm W.E." or cm of water equivalent. Most materials absorb muon energy at a rate of dE/dX = 2 MeV / cm W.E. Incoming muon flux drops off as the cosine squared of the angle from zenith
Muon flux accepted by the detector will depend on the spacing between the detector and the cos square drop and is assumed for vertical orientation.
6. TIMING FROM RAW DATA
A brief attempt at explaining a time extraction from raw data.
A windows-based program has been developed that will allow one to review a raw text data file, as well as to translate it into a form that can be analyzed using Excel.
1 Browse the input data by record or event. Translates each field and display meaning.
2 Compile statistics over the entire file.
3 Output Events File for analysis using Excel. One record for every event in data file.
4 Output Lifetimes files for analysis using Excel. One record for every pair of channel triggers within an event that occur within a user-specified range of time.
A copy of this program may be downloaded.