Difference between revisions of "Doppler Broadening"
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− | =Theory of | + | Spent fuel casket density: |
− | == Photon emmision along direction of fission fragment | + | |
+ | =Theory of Doppler Broadening= | ||
+ | == Photon emmision along direction of fission fragment velocity== | ||
<math>E_{shift} = E_{photon} \frac{1-\beta \cos(\theta_{photon}^i)}{\sqrt{1-\beta_i^2}}</math> = amount of energy the gamma ray was shifted by | <math>E_{shift} = E_{photon} \frac{1-\beta \cos(\theta_{photon}^i)}{\sqrt{1-\beta_i^2}}</math> = amount of energy the gamma ray was shifted by | ||
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<math>\theta_i</math> is the polar emission angle of excited fragment and <math>\beta_i</math> the fragment velocity<br> | <math>\theta_i</math> is the polar emission angle of excited fragment and <math>\beta_i</math> the fragment velocity<br> | ||
− | <math>\beta_i</math>=0.04634<math>\sqrt{\frac{E_i[MeV]}{A_i[u]}}</math> | + | <math>\beta_i</math>=0.04634<math>\sqrt{\frac{E_i[MeV]}{A_i[u]}}</math><br> |
+ | |||
+ | |||
+ | '''Our Calculations'''<br> | ||
+ | |||
+ | For example for energy E=2617 keV and the fragment velocity v=<math>10^9</math> cm/s(speed of light c=3x<math>10^{10}</math> cm/s, <math>\beta</math>=0.033, <math>\sqrt{1-\beta^2}</math>=0.999455352)<br> | ||
+ | We obtained the following results for different angles between the direction of the fission fragment propagation and the direction of the gamma emission<br> | ||
+ | |||
+ | (i) <math>\theta</math>=<math>0^0</math><br> | ||
+ | |||
+ | <math>E_{shift}</math>=2532.02 keV<br> | ||
+ | |||
+ | (ii) <math>\theta</math>=<math>90^0</math><br> | ||
+ | |||
+ | <math>E_{shift}</math>=2618.43 keV<br> | ||
+ | |||
+ | (iii) <math>\theta</math>=<math>180^0</math><br> | ||
+ | |||
+ | <math>E_{shift}</math>=2704.83 keV<br> | ||
+ | |||
+ | FWHM(for energy 2617 keV)=2.5 keV(experimental data)<br> | ||
+ | |||
+ | Energy difference <math>E_{shift180^0}</math>-<math>E_{shift90^0}</math>=172.8 keV. This result shows us that we do not have Doppler Shift.<br> | ||
== Photon emission off fission fragment velocity axis== | == Photon emission off fission fragment velocity axis== | ||
= Cf-252 Fission = | = Cf-252 Fission = | ||
− | + | The table below from http://www-aix.gsi.de/~wolle/ identifies gamma energies (in keV) for several fission fragments of Cf-252. | |
+ | [[Image:Cf-252_FF_Egamma_Table.gif]][[Image:Cf-252_FF_Egamma_Table1.jpg]] | ||
+ | [[Image:Cf-252_FF_Egamma_Table2.jpg]][[Image:Cf-252_FF_Egamma_Table3.jpg]] | ||
− | + | ||
+ | ==Photon Spectra from Cf-252 == | ||
=Measurements in the Beam test lab with HpGe and BC408 = | =Measurements in the Beam test lab with HpGe and BC408 = | ||
[[June 15,2007 Cf-252 measurements with HpGe & neutron sensitive scintillators in coincidence]]<br> | [[June 15,2007 Cf-252 measurements with HpGe & neutron sensitive scintillators in coincidence]]<br> | ||
[[June 19,2007 Cf-252 measurements with HpGe & neutron sensitive scintillators in coincidence]]<br> | [[June 19,2007 Cf-252 measurements with HpGe & neutron sensitive scintillators in coincidence]]<br> | ||
− | [[June 19,2007 Cf-252 measurements of gamma-spectrum using HpGe ungated]] | + | [[June 19,2007 Cf-252 measurements of gamma-spectrum using HpGe ungated]]<br> |
+ | [[June 19, gamma-singles spectra of a Cf-252 source]]<br> | ||
+ | [[June 25,2007 Cf-252 measurements of gamma-spectrum using HpGe ungated]]<br> | ||
+ | [[June 25,2007 Cf-252 measurements of total gamma-spectrum using HpGe ungated]]<br> | ||
+ | [[June 27,2007 Cf-252 measurements with HpGe detector and BC408]]<br> | ||
+ | [[July 3,2007 Cf-252 without lead container measurements with HpGe & fast plastic scintillators in coincidence]]<br> | ||
+ | [[July 6, 2007 Neutron Capture in lead]]<br> | ||
+ | [[July 10, 2007 Division of gated to ungated spectra of Cf-252]]<br> | ||
+ | [[July 11, 2007 Experimental setup]]<br> | ||
+ | |||
+ | |||
+ | |||
+ | [[Results and Discussion]]<br> | ||
+ | |||
+ | == Measurements at the IAC == | ||
+ | |||
+ | [[Image:HuntsIACgraphs.pdf]]<br> | ||
+ | [[Image:promptg02_cf252_IAC.pdf]] | ||
+ | |||
+ | =Details of Cf-252 Source= | ||
+ | The manufacturers description of the source [[Image:CF-252-Description.pdf]]<br> | ||
+ | Gamma and Neutron activity curves[[Image:CF-252-gamma-n-activitycurves.pdf]] |
Latest revision as of 07:48, 7 December 2008
Spent fuel casket density:
Theory of Doppler Broadening
Photon emmision along direction of fission fragment velocity
= amount of energy the gamma ray was shifted by
where
=- for an excited fragment in det-2
is the polar emission angle of excited fragment and the fragment velocity
Our Calculations
For example for energy E=2617 keV and the fragment velocity v=
We obtained the following results for different angles between the direction of the fission fragment propagation and the direction of the gamma emission
(i)
(ii)
(iii)
FWHM(for energy 2617 keV)=2.5 keV(experimental data)
Energy difference
Photon emission off fission fragment velocity axis
Cf-252 Fission
The table below from http://www-aix.gsi.de/~wolle/ identifies gamma energies (in keV) for several fission fragments of Cf-252.
Photon Spectra from Cf-252
Measurements in the Beam test lab with HpGe and BC408
June 15,2007 Cf-252 measurements with HpGe & neutron sensitive scintillators in coincidence
June 19,2007 Cf-252 measurements with HpGe & neutron sensitive scintillators in coincidence
June 19,2007 Cf-252 measurements of gamma-spectrum using HpGe ungated
June 19, gamma-singles spectra of a Cf-252 source
June 25,2007 Cf-252 measurements of gamma-spectrum using HpGe ungated
June 25,2007 Cf-252 measurements of total gamma-spectrum using HpGe ungated
June 27,2007 Cf-252 measurements with HpGe detector and BC408
July 3,2007 Cf-252 without lead container measurements with HpGe & fast plastic scintillators in coincidence
July 6, 2007 Neutron Capture in lead
July 10, 2007 Division of gated to ungated spectra of Cf-252
July 11, 2007 Experimental setup
Measurements at the IAC
File:HuntsIACgraphs.pdf
File:Promptg02 cf252 IAC.pdf
Details of Cf-252 Source
The manufacturers description of the source File:CF-252-Description.pdf
Gamma and Neutron activity curvesFile:CF-252-gamma-n-activitycurves.pdf