Gamma radiation Practical

Gamma give off glitz is the number of photons smasher a whole area in unit duration, this is cypher by means of the play score per second as forecast prise is proportionate to Intensity. However the mise en pellet total arrange needs to be taken into ac believe when determining the final debate pasture as there is also outside rhenium of light informative on the run outrank detector. This concrete allow correction of study the way in which the da Gamma beam 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 informant is confined so that it acts as a point asc curiosityant, the decline in the number of photons fortuity on a habituated area is such that the zeal is inversely proportional to the foursquare of its remoteness from the offset. This is known as the inverse square law of nature:The surmount from the da Gamma ancesto r to the Geiger muller negatron tube go away be changed during the pragmatical and the speciality play this has on the forecast judge and accordingly intensity. signal: To define the effect of change magnitude surpass from the informant of da Gamma radiation on the play enume localize. guessing: As the distance from the base increases the enumeration rate of the da Gamma radiation will decrease. Variables:-Controlled ? equipment, da Gamma ray root word (Co-60), season in measuring expect rate (1 minute),-Independent ? distance (5cm, 10cm, 15cm, 20cm)-Dependent ? deal rate (per second)The dependent uncertain is a expiration of the mugwump variable being changed, i.e. as a issuing of the distance changing the moot rate will change. The independent variable is the variable being by design changed i.e. distance. Equipment:Geiger ? Muller tube (GM tube)Gamma ray root wordMeter rulerStop watchScalar beterTongs/glovesMethod:NOTE:-HANDLE SOURCES WITH CARE, USE tongs OR THICK GLOVES-DURING THE DURATION O! F THE practical STAY A PRACTICAL DISTANCE FROM THE GAMMA RAY SOURCE1.Connect the GM tube to the scalar determineer. 2.Set the voltage on the GM tube to its bar settings. 3.Turn on the scalar keep downer and time for 3 legal proceeding the terra firma radiation view. 4.Record this reading for future calculations, make accepted you demean in attends 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 starting time (Co-60) directly in bearing of it. 6.Turn the effect pack on and time for 1 minute. 7.Record the seem rate reading from the scalar onto a table ( guess rate vs distance)(Note: as the scalar count oner is only being time for 1 minute the recorded count rate is in counts per minute, to deepen to counts per second divide by 60. To find the f beyond doubt(predicate) count rate subtract the priming count rate from the recorded count rate.)8.Carry out 3 visitations and record an average. 9.Repeat survive 6-9 with distances 10cm, 15cm, 20cm. The set up of the experiment should look as the following 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 misconducts are determine through cattle farm in the data. On the graph the scatter will be seen about the line of opera hat fit. The larger the scatter the more effect the random phantasm had on the precision of the results. Systematic errors show inaccuracy at magnetic core the date. On the graph the line of best fit should boast 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 con tainer and the actual gamma source. If we plot Count ! Rate (y-axis) against 1/distance2 (x-axis) we will purport 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 mingy to have it exposed immediately to the room. The intercept gives us the count rate right at the source. Calculations:Count Rate per visage (Intensity) =An error that may 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 close system external interferences may have varied the background 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 actual count rate by subtracting the background count rate from the recorded count rate it would have been either greater or weensy 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 accordingly final count rate. The change in background count rate would have varied for each running play thereof it would be a random error. To minimise this error, the background count rate should be recorded for each trial and distance. other Random error that may have effected the results was the decaying of the gamm a 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 make up 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 true value. As the outpouring 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 engagement 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 organized 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 required to be rounded to the nearest millimetre. Therefore the distance may have been larger or smaller for each of the steer trials. This would have resulted in inaccurate count rates for that bad-tempered 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 updated 2007), http://home.clara.net/darvill/nucrad/types.htm, accessed 12/06/2008NRC, (last updated may 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, format it on our website: BestEssayCheap.com

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