Rachel simulated yield output

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(Major changes reflect the output and operation of version 1.)
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''This page uses the output of Rachel version 2.0.8 beta.''
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''This page uses the output of Rachel version 1, which is more intuitive than that of the beta versions.''
The output to the terminal from a "simulated yields" calculation has the following format:
The output to the terminal from a "simulated yields" calculation has the following format:
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The simulation output now uses the standard definition of efficiency, and the default efficiency curve for any detector can be adjusted by the user.  The user will find prompts for the details of the planned beam run, and estimated absolute measured counts will be calculated and displayed.  The display format looks like the following:
<pre>
<pre>
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Experiment 1 Detector  2
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Experiment 1
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                                      Raw                    Count  Gamma  **Est. intr.  "Corrected"               
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Target excitation by Z,A = 54,136 at 517 MeV. Mean scattering angle = 45.0 deg.
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Band       Spin   Band   Spin    *Counts        Error   Rate(Hz)  E(keV)    effic.(1)   ***Counts        Error     
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Detector 1
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----------------------------------------------------------------------------------------------------------------
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Single crystal at theta, phi = 45.0, 45.0 deg. Solid angle = 0.06 sr.
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    gsb   18.0    gsb    16.0        864          29 0.002001    686.0       0.271        3266          198
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This simulation does not include random gaussian scatter. Counts represent the cross sections calculated by Gosia.     
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     gsb    16.0     gsb   14.0     21056          145 0.048741    658.7       0.277        78074        3941
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      Transition            |  Gammas incident      |                    Fraction of |        Observed Counts       
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     gsb    14.0     gsb    12.0    400895          633  0.927999    626.6       0.284     1360201        68044
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                              |  on Ge detectors      | Gamma               Incident    |                               
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    gsb   12.0     gsb    10.0    5914064        2432 13.689963    579.7        0.296     21145020      1057287
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  Initial        Final        |                      | Energy **Detector  Gammas      |                               
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    gsb    10.0     gsb    8.0  65755367        8109 152.21149    512.4       0.315    211214415    10560753
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    Band Spin     Band Spin   | Counts   *Error     | (keV)   Efficiency  Detected   | Rate(Hz)   Counts  ***Error     
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    gsb     8.0     gsb    6.0 527950313        22977 1222.1072    426.3        0.343  1470121661     73506111
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-------------------------------------------------------------------------------------------------------------------------
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    gsb    6.0     gsb    4.0 2866371774        53539 6635.1198    325.6        0.379  7435917854    371795919
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    gsb 1.5      gsb  0.5     4.662e+06 2.332e+05    100.0 0.00049     0.09962      1.075e+00  4.644e+05  6.815e+02
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    gsb    4.0    gsb    2.0 8174712130       90414 18922.944    213.5       0.382 21045773464  1052288699
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    gsb 2.5     gsb 0.5    1.570e+07  7.848e+05     200.0 0.00179     0.36853      1.339e+01  5.784e+06  2.405e+03
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    gsb    2.0    gsb    0.0  706191594        26574 1634.7027     93.3       0.078  8631491935    431574719
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       a  2.5     gsb 0.5     1.079e+04  5.647e+02    250.0  0.00189     0.38907      9.719e-03  4.199e+03  6.480e+01
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      a  2.5      gsb 1.5     9.816e+02 7.705e+01    150.0  0.00135     0.27823      6.322e-04  2.731e+02  1.653e+01
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      a  2.5       b  3.5     4.689e+05 2.376e+04      75.0  0.00015     0.0312        3.387e-02  1.463e+04  1.210e+02
</pre>
</pre>
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The "Observed Counts" are calculated using the efficiency curve from the detector library or a detector created by the user.  The "Detector Efficiency" <math>\epsilon</math> is the usual definition.  Possion counting errors are based on the observed counts, while additional error on the ''total'' efficiency-corrected counts may be added by the user.
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* The "Corrected Counts" column gives the true particle-gamma count emitted into the solid angles of the particle and Ge detectors.  This is equivalent to the total counts for the beam run if the detectors were blackbodies (had 100% efficiency), or if the raw counts were corrected for the absolute p-gamma efficiency.
 
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* The "Raw Counts" column is only used in this output and is not passed to Gosia.  The raw counts are the estimated p-gamma counts in the raw data, assuming an approximate absolute ''intrinsic'' efficiency for Gammasphere. 
 
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* The "Est. intr. effic." column gives the ''assumed'' absolute ''intrinsic'' efficiency <math>(\epsilon_{intr})</math> of the Ge detector used to calculate the value in the "Raw counts" column.  For example, at 1333 keV, Gammasphere typically has an absolute efficiency of 9% for 100 installed detectors.  Since the solid angle coverage of these 100 detectors is ~6.1 sr, the ''intrinsic'' efficiency is approximately <math>9% * 4\pi / 6.1 = 18.5%</math>.
 
===Accuracy checking===
===Accuracy checking===
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The ''intrinsic'' efficiency has been estimated more accurately in version 2.0.8.beta.  This will make a noticeable change in the "Raw counts" column.   
The ''intrinsic'' efficiency has been estimated more accurately in version 2.0.8.beta.  This will make a noticeable change in the "Raw counts" column.   
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===Estimating count rates in a planned experiment===
 
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Since the "Corrected counts" column gives the absolute emitted particle-gamma counts into the particle- and gamma-detector solid angles (for 100% efficiency), these values can be combined with better known values of the particle and gamma efficiencies to predict more accurate "raw" count rates, if the approximate predicted raw counts are not accurate enough.
 
===Simulated data passed to Gosia===
===Simulated data passed to Gosia===
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Note that the "Corrected Counts" are not sent to Gosia as they appear in the table. 
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Note that Rachel operates Gosia such that efficiency-corrected "incident gamma" counts are passed to Gosia, but first they are divided by the solid angle of each Ge detector to match Gosia's calculation of yield per unit solid angle.  (This is true in Rachel versions >= 2.0.7.beta; in earlier versions this solid angle factor was neglected, which usually did not result in accuracy errors.)  All yields sent to Gosia are then multiplied by <math>4\pi</math> so that weak transitions have counts >=1.  This overall multiplicative constant of <math>4\pi</math> has no effect on fitting.  Refer to the page [[Normalization_of_yield_data | Normalization of yield data]] for more detail.
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Before the corrected counts are sent to Gosia they are divided by the solid angle of each Ge detector to match Gosia's calculation of yield per unit solid angle.  (This is true in Rachel versions >= 2.0.7.beta; in earlier versions this solid angle factor was neglected.)  All yields sent to Gosia are then multiplied by <math>4\pi</math> so that weak transitions have counts >=1.  This overall multiplicative constant of <math>4\pi</math> has no effect on fitting.  Refer to the page [[Normalization_of_yield_data | Normalization of yield data]] for more detail.
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Revision as of 16:00, 28 January 2012

Retrieved from "https://www-user.pas.rochester.edu/~gosia/mediawiki/index.php/Rachel_simulated_yield_output"
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