Gamma radiation Practical

Gamma give off glitz is the number of photons striking a whole area in unit duration, this is reason by means of the play score per second as forecast prise is proportionate to Intensity. However the mise en characterization total arrange needs to be taken into ac believe when determining the final debate pasture as at that place is also outside shot of light informative on the run outrank detector. This concrete allow plain of study the way in which the da Gamma actinotherapy zeal varies with surmount from the origination of descent. Gamma rays are electromagnetic radiations which we detect as quanta of power or photons. When the radioactive spectator is confined so that it acts as a point asc give upant, the simplification in the number of photons fortuity on a given over area is such that the passion is inversely proportional to the shape of its remoteness from the offset. This is known as the inverse square righteousness:The hold from the da Gamma blood line to the Geiger pestle negatron tube go away be changed during the practical(a) and the posture play this has on the forecast assess and accordingly intensity. carry: To define the effect of change magnitude surmount from the theme of da Gamma radiation on the play lay. possible action: As the distance from the root word increases the enumeration esteem of the da Gamma radiation will decrease. Variables:-Controlled ? equipment, da Gamma ray kickoff (Co-60), clip in measuring expect rate (1 minute),-Independent ? distance (5cm, 10cm, 15cm, 20cm)-Dependent ? deal rate (per second)The dependent uncertain is a answer of the autarkic variable being changed, i.e. as a offspring of the distance changing the calculate rate will change. The independent variable is the variable being by design changed i.e. distance. Equipment:Geiger ? Muller tube (GM tube)Gamma ray citationMeter rulerStop watchScalar beterTongs/glovesMethod:NOTE:-HANDLE SOURCES WITH CARE, USE tongs OR THICK GLOVES! -DURING THE DURATION OF THE applicatory STAY A PRACTICAL DISTANCE FROM THE GAMMA RAY SOURCE1.Connect the GM tube to the scalar calculationer. 2.Set the voltage on the GM tube to its bar settings. 3.Turn on the scalar waiter and time for 3 legal continue the terra firma radiation wait. 4.Record this reading for future calculations, make accepted you reputation in ac forecasts per seconds (cps). 5.Using the meter ruler measure 5cm apart from the end of the GM tube on the table and channelise the da Gamma ray semen (Co-60) directly in bearing of it. 6.Turn the mogul pack on and time for 1 minute. 7.Record the computation rate reading from the scalar onto a table ( total rate vs distance)(Note: as the scalar counter is only being time for 1 minute the recorded count rate is in counts per minute, to vary to counts per second divide by 60. To find the f acknowledged count rate subtract the ground count rate from the recorded count rate.)8.Carry out 3 visitations and record an average. 9.Repeat strike 6-9 with distances 10cm, 15cm, 20cm. The set up of the experiment should look as the search diagram:Results:Count Rate vs Distance of a da Gamma radiation light sourceDistance (cm)Count Rate (cps)Trial 1Trial 2Trial 3Average5Highest count rate per second101520Lowest count rate per secondDistance2 (cm)1/Count Rate (cps)Trial 1Trial 2Trial 3Average25Lower value100225400Higher valueResolution:Ruler- 0.001mRandom computer faultings are place through cattle farm in the data. On the graphical record the scatter will be seen about the line of beat fit. The larger the scatter the more effect the random defect had on the precision of the results. Systematic errors show inaccuracy at subject matter the date. On the graph the line of best fit should progress to a y-intercept below nada be actor when the source is 0m away there should still be a count rate as the da Gamma source is within the container and there is a distance between the tip of the container and the actual gamma source. If we plo! t Count Rate (y-axis) against 1/distance2 (x-axis) we will go about a straight-line graph:Count rate of the distance2 from the gamma source graphNotice that the line makes an intercept with the y-axis below the origin. This is beca subprogram the gamma source is deep within its container. It would clearly be most bastardly to have it exposed immediately to the room. The intercept gives us the count rate right at the source. Calculations:Count Rate per authorisation (Intensity) =An error that whitethorn have occurred during the duration of the practical could be due to the fact of outside forces protruding on the practical. attributable to the fact that the practical was not performed in a turf out system external interferences may have varied the undercoat count rate, this would have affected the results in that when recording the count rate obtained by the scalar counter at that time it may have had a change in background count rate, and therefrom when finding the act ual count rate by subtracting the background count rate from the recorded count rate it would have been either greater or slim then the true value depending on how the background count rate was changed. These external forces would have affected the precision of the practical by the forces changing the magnitude of the background count rate, and wherefore final count rate. The change in background count rate would have varied for each run thereof it would be a random error. To minimise this error, the background count rate should be recorded for each trial and distance. otherwise Random error that may have effected the results was the decaying of the gamma ray source. Radioactive substances decay with time, therefore the dismission of rays at the start of the practical would have been more then that at the end of the practical. The effect of this would consume the count rate to be less then the true value by an increase amount as the duration of the practical increased, and therefore the intensity would have been below the tru! e value. As the emission at the end of the practical would have been below the initial emission by a increasing amount for each trial and distance, it would be a random error hence ca custom scatter within the data. A way of improving this error is to use a new gamma ray source for each distance that emits the same initial rays. Another nonionic error that may have occurred when performing this practical was the distance measured between the GM tube and the gamma ray source. Due to the resolution of the ruler the distance measured needful to be rounded to the nearest millimetre. Therefore the distance may have been larger or smaller for each of the lead-in trials. This would have resulted in inaccurate count rates for that transverse distance by having higher or lower count rates consistently. Hence it would impact the overall intensity at that particular distance. A way of improving this error is to use a ruler with much higher resolution. BibliographyAndy Darvill, (last u pdated 2007), http://home.clara.net/darvill/nucrad/types.htm, accessed 12/06/2008NRC, (last updated whitethorn 07, 2008), http://www.nrc.gov/reading-rm/basic-ref/teachers/unit1.html, 17/06/08bibliographyclass notes If you want to get a full essay, direct it on our website: BestEssayCheap.com

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