Marks are allocated for the presentation by the student of a preliminary analysis of the data (calibration, spectra and initial identification of features) within the specified time.
Read the comments in your partner(s) reports as well as your own. Often I do not repeat comments that are common to both (or all) reports.
PHY300W is a major course, so a high level is expected of the report, in terms of accurate presentation and critical analysis of the data.
Use a decent word processor. Pay attention to proper notation, eg. subscripting etc. Instead of cobalt-60 use the proper superscripted form, etc.
Use accepted scientific style. Check whether it should be X-ray or x-ray.
Always use a spell checker. The real world expects UCT graduates to produce written work of high quality.
Define all symbols, eg. if you suddenly start using the symbol m in the discussion of Compton scattering, define it as electron mass, etc
Punctuate properly, e.g. do not write: "the energy that a photon can carry ie the backscattered photon"; use the correct form of the abbreviation: i.e.
Be quantitative rather than loosely descriptive, e.g. instead of saying "this causes a peak slightly below the full energy peak" rather say "this causes a peak 250 keV below the full...". Instead of saying "the energy is a bit low to be the barium x-ray" rather say "the energy of the observed peak lies 3 standard deviations below the energy of the barium K-alpha x-ray."
Provide a scale diagram of apparatus, showing source detector distances, presence or absence of lead shield, etc.
Provide a block diagram of the electronics used
All figures should be captioned.
Proper scales must be chosen for graphs, and all axes properly labelled, and units shown
Show all calibration curves. Interpret the chi-squared per degree of freedom as indicative of a good or poor fit .
Tabulation of expected and observed energies for features such as photopeaks, Compton edges, backscatter peaks, x-ray peaks
On careful rereading of what you have written you will often discover scientifically incorrect sentences, e.g. "The binding energy of the emitted electron is transferred to other electrons...". Of course an electron, once emitted, has no binding energy.
The Am-241 spectrum has peaks only in low channel numbers. When this spectrum is printed, it should have the x-range expanded so that only these channels are shown. There is no need to all all 1024 channels if there is nothing in them.
When presenting two spectra that need to be compared, e.g. Am-241 spectrum with the lead sheet below the source, and the spectrum with lead sheet above the source, always choose the same x-range so that the spectra can be compared by overlaying them.
Capitalization: e.g. Compton effect (not "compton"); "a backscatter peak" (not "a Backscatter peak")
Incorrect use of significant figures, e.g E = 1.4623 +- 0.0214 MeV
Use of phrase "channel number" for "pulse height(channels)"
Imprecise use of language, e.g. "the range of incident angles from 0 to 180 form a continuum on a gamma ray spectrum culminating in an edge". Clearly the angles do not form an edge. ALWAYS reread your report critically before handing it in. Scientific descriptions must be correct, clear and precise .
Misuse of the word "theoretical" where "expected" is meant, e.g. in a table where known energies of gamma rays are listed, it is wrong to call these theoretical energies. There is no known theory that predicts the value of the 1.332 MeV energy for a gamma ray from cobalt-60 decay.
Be careful with use of the word "theoretically", as in "Theoretically no peak should be observed". What theory is this? Probably you mean "No peak was expected, however..."
When a straight line of the form h = a + b E is fitted to the calibration data, usually a non-zero value of the intercept, a, results. A statement like "In theory a should be zero, but it is not because of physical imperfection of the apparatus" is quite wrong. The intercept, a, is non zero because of an offset in the electronics, probably the pulse amplifier or the ADC.