Difference between revisions of "Gamma Spectroscopy (NORM and TENORM)"

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(Created page with "<br> N = number of nuclides<br>D = disintegration rate (Bq, Ci, dimension s-1)<br>A = activity is disintegration rate D per unit of volume or unit of mass (dimension s-1)<br>...")
 
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N = number of nuclides<br>
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D = disintegration rate (Bq, Ci, dimension s-1)<br>
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A = activity is disintegration rate D per unit of volume or unit of mass (dimension s-1)<br> &nbsp; &nbsp; We distinguish between two notions:<br>
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&nbsp; &nbsp; As(i) = specific activity is activity per unit of mass of that particular element the actual<br>&nbsp; &nbsp; &nbsp;  radionuclide i belongs to. This notion is also used to express the activity of a<br>&nbsp; &nbsp; &nbsp; particular radiolabelled molecule in relation to the total mass of the same molecule<br> &nbsp; &nbsp; &nbsp; (labelled and unlabelled) in the sample (for instance when the inactive molecule is present<br> &nbsp; &nbsp; &nbsp;  as a carrier).<br> &nbsp; &nbsp; Ac(i) = activity concentration is the activity of a special radionuclide ''i'' or all present<br> &nbsp; &nbsp; &nbsp; radionuclides (AcT = Ac(i) = total aktivity) per unit of volume or unit of weight  of a radioactive<br> &nbsp; &nbsp; &nbsp; sample.
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N,D and A may, in addition, have an index t (i.e. Nt, Dt and At). This denotes the parameter values at time t relative to a starting time t = 0.
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R = counting rate (cps, cpm or generally cpt where t should be defined, dimention s-1)
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S = number of counts
  
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N, D, A, R and S may, in addition, have indexes B = background, T = total or N = net. The relations between them are: RN = RT - RB and SN = ST - SB. Other indexes may also be used, for instance SCr-51 in order to separate from SFe-59.
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N = number of nuclides<br>D = disintegration rate (Bq, Ci, dimension s-1)<br>A = activity is disintegration rate D per unit of volume or unit of mass (dimension s-1)<br>We distinguish between two notions:<br>As(i) = specific activity is activity per unit of mass of that particular element the actual radionuclide i belongs to. This notion is also used to express the activity of a particular radiolabelled molecule in relation to the total mass of the same molecule (labelled and unlabelled) in the sample (for instance when the inactive molecule is present as a carrier).<br>Ac(i) = activity concentration is the activity of a special radionuclide i or all present radionuclides (AcT = Ac(i) = total aktivity) per unit of volume or unit of weight of a radioactive sample.<br>N,D and A may, in addition, have an index t (i.e. Nt, Dt and At). This denotes the parameter values at time t relative to a starting time t = 0. <br>R = counting rate (cps, cpm or generally cpt where t should be defined, dimention s-1)<br>S = number of counts
 
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N, D, A, R and S may, in addition, have indexes B = background, T = total or N = net. The relations between them are: RN = RT - RB and SN = ST - SB. Other indexes may also be used, for instance SCr-51 in order to separate from SFe-59.
 
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Examples:
 
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We consider the following three samples:<br>P1: 1 kg pure iron (Fe). This sample contains10kBq of the radionuclide 59Fe.
 
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P2: 1 kg steel consisting of 70 weight% iron and 10 weight% of each of the elements Cr, Ni and Mo. The sample contains 10 kBq of 59Fe and 10 kBq of 51Cr.
 
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P3: A 1L aqueous solution with 100 g dissolved FeCl3 and 100 g dissolved CrCl3. This corresponds to 35 g dissolved Fe and 31.6 g dissolved Cr. The solution contains 10kBq 51Cr and 10 kBq 59Fe.
 
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For sample P1 we then have:<br>As(59Fe) = 10 kBq/kg Fe<br>Ac(59Fe) = 10 kBq/kg sample
 
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For sample P2:<br> As(59Fe) = 10 kBq/0.7kg = 14.3 kBq/kg Fe<br> As(51Cr) = 10 kBq/0.1kg = 100 kBq/kg Cr<br> Ac(59Fe) = 10 kBq/kg sample<br> Ac(51Cr) = 10 kBq/kg sample<br> AcT = 20 kBq/kg sample
 
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For sample P3:<br> As(59Fe) = 10 kBq/0.035 kg Fe = 285.7 kBq/kg Fe<br> As(51Cr) = 10 kBq/0.0316 kg Cr = 216.5 kBq/kg Cr<br> Ac(59Fe) = 10 kBq/1.2 kg sample = 8.33 kBq/kg sample and/or 10kBq/l sample.<br> Ac(51Cr) = 10 kBq/1.2 kg sample = 8.33 kBq/kg sample and/or 10kBq/l sample<br> AcT = 20 kBq/1.2 kg prøve = 16.66 kBq/kg prøve og/eller 20 kBq/l prøve.
 
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Indexes may be omitted when the meaning of the parameters cannot be misunderstood.<br>
 
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Revision as of 16:13, 20 June 2012

N = number of nuclides
D = disintegration rate (Bq, Ci, dimension s-1)
A = activity is disintegration rate D per unit of volume or unit of mass (dimension s-1)
    We distinguish between two notions:
    As(i) = specific activity is activity per unit of mass of that particular element the actual
      radionuclide i belongs to. This notion is also used to express the activity of a
      particular radiolabelled molecule in relation to the total mass of the same molecule
      (labelled and unlabelled) in the sample (for instance when the inactive molecule is present
      as a carrier).
    Ac(i) = activity concentration is the activity of a special radionuclide i or all present
      radionuclides (AcT = Ac(i) = total aktivity) per unit of volume or unit of weight of a radioactive
      sample. N,D and A may, in addition, have an index t (i.e. Nt, Dt and At). This denotes the parameter values at time t relative to a starting time t = 0. R = counting rate (cps, cpm or generally cpt where t should be defined, dimention s-1) S = number of counts

N, D, A, R and S may, in addition, have indexes B = background, T = total or N = net. The relations between them are: RN = RT - RB and SN = ST - SB. Other indexes may also be used, for instance SCr-51 in order to separate from SFe-59.

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