THIRD
YEAR LABORATORY 2006
Laboratory
Organisation
PHYS3040,
PHYS3070, PHYS3110, PHYS3120
Experimental Physics A1, A2, B1, B2
and
PHYS3770, PHYS3780
Lasers and Spectroscopy Laboratory,
Photonics Laboratory
Introduction
 |
| A light bulb filament
as seen in the Scanning Electron Microscope |
Welcome
and congratulations! You have chosen to take one or
more of the third year physics laboratory courses.
It is true that, like any other creative endeavour,
hands-on laboratory work can be time consuming, difficult
and sometimes frustrating and is quite 'messy' compared
with the elegance of textbooks BUT these practical
courses are probably the most interesting, challenging
and important physics you will undertake as an undergraduate.
Ultimately, it is in the laboratory that physical
theories are proved or disproved and that technology
is tested and refined. In your lectures you learn
about physics; it is only in the laboratory that you
can make physics really happen ! |
Third
Year Laboratory Staff:
Main
Laboratory: Room 101, Main Building (map K15) - Phone: 9385
4543
Optoelectronics
Teaching Laboratory: Rm LG46, Main Bldg - Phone: 9385 4636
Tutors
: Paul CHILDS, Suhrawardi ILYAS, Andrew SEE
In addition, various academic staff members will be rostered
for experiment assessment duties in the laboratory. The
laboratory staff are ready to assist you if you run into
any difficulties - do not hesitate to ask for help.
IT
IS UP TO YOU TO TALK TO THE STAFF IF YOU HAVE A PROBLEM
!
Class organisation and
attendance
Lab
classes run every weekday afternoon from 1 to 5 pm in the
main laboratory, while the laser and optoelectronics teaching
laboratory is normally open for four hour classes, three
or four times each week (5-9 pm when in sufficient demand).
You must attend one four hour laboratory class per
week for each of the lab courses you have enrolled in,
on the day(s) you have chosen. Be punctual to class - if
you are more than 15 minutes late your equipment will become
available for other students to use. As indicated on the
experiment list, you will work individually on some experiments;
if you wish, you may choose a partner for others; for still
other experiments you will be assigned a partner (or sometimes
two). To make best use of your class time you should come
into lab with all the necessary notes, folders, etc. and
have done the required background reading so that you know
what it is that you are going to do and how you will do
it. Think and investigate before you ask questions. Genuine
problems are gladly dealt with, provided you=ve made a reasonable
attempt to find the solution.
If
you cannot attend a scheduled lab class for some reason,
you must write a formal application to the Registrar for
exemption from attendance at the class. Follow the procedure
given in the A-Z
Guide (at myUNSW) regarding 'attendance
and absence'. The Registrar will then inform both you
and the School of Physics whether your absence is approved.
Please also give a copy of the relevant
medical certificates etc. to the lab director, as information
from the registrar can sometimes take a long time to filter
down. Remember that if you attend less than 80% of the possible
classes in a course you may be refused final assessment
in that course!
Each
absence which has not been approved will lower your
final mark by 1%. |
The
third year laboratory functions, as far as practicable,
as an 'open' laboratory where you can
work at your own pace. This means that, as well as attending
scheduled lab classes, you are encouraged to come in at
other times (the main lab is usually also open 10 - 12
am) to finish off experiments, do extra work, use the
computers, reference library etc. Thus, you don't have
to rush your lab work but have time to think and plan,
perform measurements carefully, reflect on your results
and gain a better understanding of the physics involved.
Make sure, however, to book beforehand if you want to
work outside of your scheduled lab times since, in the
afternoons, other classes may need to use the experimental
equipment while in the mornings a member of staff must
always be present (for safety reasons) in the laboratory
if you wish to work there.
Recording
and presentation of experiments
You
are required to record all your experimental work, individually,
in a laboratory diary (log book). This
diary is the very lifeblood of an experimentalist ! The
diary must be kept in a bound exercise
book. While the experiment is being done, all raw
experimental results, observations and comments should be
entered, in pen, directly into this book.
NEVER RECORD EXPERIMENTAL
RESULTS ON LOOSE SHEETS OF PAPER !
Do
not erase or white out any results - cross them out with
a single line (you may need them again!). Whenever possible,
data should be tabulated and plotted as it is being taken.
It is good practice to do a quick calculation during data
collection to check that the measured effect is roughly
as expected (see separate sheet on 'Experimental
Technique and Errors'). Remember to
date your log book entries and to note down the names and
identifying numbers of the equipment you use.
Apart
from the raw experimental results, your diary should contain
data analysis, graphs, diagrams of any non-standard set-ups/circuits
used, etc. You must write sufficient information
into your log book so that, at some later stage, you can
use it as the basis for a detailed scientific
report or poster for any one of the experiments;
don't waste your time on verbose accounts of apparatus,
method and theory which can be found in the lab notes or
folders.
In
every experiment whose aim is to measure a physical property,
an estimate of the reliability or 'error'
in the final result must be given. This should not, however,
become a major task - an informed approximation of the most
important error sources is normally sufficient.
If you use computer software for data analysis you still
need to understand what the software does and the factors
limiting experimental accuracy. It is no good just saying
"the computer did it". If your results
don't agree with theory or with other published results,
explain why. It is often in the exceptions to rules that
interesting new physics is found.
At
the end of each experimental write-up a discussion/conclusion
should be included. Here, the important features of the
experiment and the significance of the results should be
discussed. If you have ideas on how to improve the experiment,
include these as well. Sensible, original suggestions will
get you better grades.
To help you understand the methods, apparatus and physical
principles involved in the experiments, we have built up
a library of information folders and books. The information
folders may be borrowed after filling out the appropriate
card. The borrowing operates on a 'trust' system; please
don=t monopolise the folders, return them as soon as you=ve
had the experiment marked since other students need to use
them too. Books should not be removed from the lab
but you may use them in the laboratory any time it is open.
You
will be issued with a sample log book at the beginning of
the semester. This book has alternate ruled and grid pages.
The grid pages are useful for tabulating results and for
drawing rough graphs as the data is taken. Graphs drawn
on loose sheets, (graph paper of various kinds is available
in the lab) computer printouts and any other loose sheets
should be pasted into your log book, so that they can't
be accidentally lost.
Note
for PHYS 3770/80 students! For some of the experiments,
experiment notes, interactive diagrams of experimental setups,
safety warnings etc, can now be accessed on www.webct.unsw.edu.au.
Log-in using your student ID and password, select 'PHYS3770
Laser and Spectroscopy Laboratory' and click on the 'Experiment
Browser' icon to gain access to the information.
Assessment
Assessment
of each student's individual work is carried out by academic
staff, each of whom will be available in the laboratory
for 2 hours/week and will specialise in marking a particular
subset of experiments. A roster sheet of the assessors'
times and specialist experiments will be posted up on the
lab noticeboard. Put your name down in the 'Marking
Queue' diary, for an appropriate time slot, when
you want an experiment marked.
Experiments
must be marked off in the order they were done
and within 10 working days (i.e. 2 calendar
weeks) of completing the experimental work.
Late
assessment will be penalised 1/2 mark for each week,
or part of a week, past the 10 day deadline. |
You will be issued with a new experiment only if you have
no more than one unmarked experiment. In
week 13 of each session, however, no new experiments
will be issued to students unless all their other experiments
have been marked, while in week 14
no new experiments may be commenced. Do
not save up experiments for marking in week 14 as demonstrators
will mark only one experiment / student / course
in this last week of session.
Assessment
of each completed experiment is based on an individual discussion
with, and log book inspection by, the assessor.
The assessment interview is very much an interactive one-to-one
teaching session where students often learn as much as they
do during the rest of the experiment. The quality of the
log book record (logical recording of data, calculations,
comments, tables, graphs, etc.) not neatness,
will be taken into account.
The
criteria by which a completed experiment is assessed include:
technique
and apparatus:
A
grade out of 10 will be awarded for each completed experiment.
Typical requirements for grades are as follows:
<
5 fail
technique, results and/or theory unsatisfactory; grades
<5 are not usually awarded, the student is asked to repeat
the offending section(s) of the experiment or to do some
more reading/thinking/analysis
5
borderline pass
technique, theory and results barely satisfactory; results
poor or gaps in understanding technique or theory
6
satisfactory
technique, results and theory satisfactory; no critical
analysis or initiative
7
good solid work
good technique, results and theory and some evidence of
critical analysis
8
superior
as for 7 but with critical evaluation of technique/theory
and improvements to technique/theory suggested
9
excellent
as for 8 but with implementation of some improvements
10
outstanding
as for 9 but with improvements and extensions of experiment
implemented
Thus,
an experiment competently carried out and written up (as
per the experiment notes) would normally earn a grade of
7 to 7.5 and evidence of critical appraisal, extra work,
initiative or originality is needed to obtain higher grades.
You should ensure that after each assessment the grade,
date and assessor's initials/signature are entered both
in your log book and in the 'Laboratory Student
Records' folder.
Finally,
a reminder: copying other people's work and submitting it
for assessment (i.e. plagiarism)
is classed as academic misconduct and is
viewed very seriously by the University (see the "A-Z
Guide"). You are certainly encouraged to interact
with other students during lab classes, to help them and
to discuss your experimental work with them. The write-up
of each experiment should, however, be your own work.
The
'points' system
The
'Experiment List' is divided into groups, according to topics
or techniques, and each experiment is allocated a 'points'
score. The number of points represents the time,
in hours, that an average student would spend in
the laboratory doing the actual experimental work for a
given experiment. You can expect to spend about half as
much time again, on each experiment outside of lab time
analysing results, reading references, thinking, etc.
A ' + ' after the points score indicates that extra points
can be gained for optional parts of an experiment. You can
also get extra points if you yourself wish to extend an
experiment in some way, but always discuss this
with a demonstrator first to see if your proposal
is feasible and the necessary equipment can be made available.
Course
requirements
Students
taking:
a)
PHYS3040 or PHYS3070 Experimental Physics A1 or A2
are
required to have 45 points worth of experiments, from different
groups, marked by the end of week 14 in
session 1 or session 2 respectively. At least 25 points
worth of experiments should be marked by week 9 of the session.
In addition to having 45 points worth of
experiments assessed (in 3070 up to 16 points may be credited
for the Physics Participation Program - details available
mid session 1), you are required to present a scientific
report or poster
on one of the experiments which you have performed. The
report/poster will contribute 5 points
towards the final mark. Guidelines on the format of the
reports/posters will be issued separately. The experiments
for which reports/posters are required will be notified
in week 8 of each session. The reports/posters will be due
in week 10 of the session.
Late
reports/posters will be penalised 1/2 mark for each
day late (1 mark/weekend). |
b) PHYS3110 or PHYS3120 Experimental
Physics B1 or B2
are
required to have 50 points worth of experiments, from different
groups, marked by the end of week 14 in session 1 or session
2 respectively (in 3120 up to 16 points may be credited
for the Physics Participation Program). At least 27 points
worth of experiments should be marked by week 9 of the session.
c)
PHYS3770, PHYS3780 Lasers and Spectroscopy, Photonics Laboratories
are
required to have 45 points worth of experiments, from the
first two experiment groups, marked by the end of
week 14 in the session. At least 25 points worth
of experiments should be marked by week 9 of the session.
In addition to having 45 points worth of experiments
assessed, you are required to complete a written
assignment on the hazards associated with lasers
and on various aspects of laser safety. The assignment will
be handed out in week 1 and will be due in week 3. It must
be satisfactorily completed before any experiments
involving higher powered or infra-red lasers are commenced.
The assignment will contribute 5 points
towards the final mark. If you have had the assignment assessed
in a previous course, you will be required to complete 50
points worth of experiments.
Late
assignments will be penalised 1/2 mark for each day
late (1 mark/weekend). |
* * * * * * *
Note:
If you score less than the required 50 points total in any
of the above courses, your final mark will be decreased
accordingly; if you score more, your best
45 (or 50) experimental points will be used to calculate
the final mark. For special programs the above allocations
may be varied at the discretion of, and after consultation
with, the laboratory director.
Safety
and etiquette
None
of the experiments in the lab are dangerous, provided
that you follow normal practice. Various hazards
do, however, exist in the laboratory due to the use of high
voltages, cryogenic liquids, radioactive isotopes, X-rays,
lasers, compressed gases, poisonous chemicals, etc. You
will be given a separate sheet on 'Safety
in the Laboratory', a copy of which you must read, sign
and return before commencing laboratory classes. Safety
rules relevant to each experiment are given in the individual
experimental notes and should be carefully observed. Before
commencing any experiment always check with a demonstrator
about potential hazards peculiar to that experiment. It
is your responsibility to work at all times
in a way that ensures your own safety and that of other
persons in the laboratory.
In general
:
