Table of Contents ECSS Model Page
Background Information Radiation sources and effects
Dose models

SPENVIS uses trapped particle (TREP, TREP_JUP) and solar proton fluence spectra to estimate doses behind Al shielding, using the following dose models:

The input parameters and options for the models are described below. When the input form has been completed, pressing the button will start the calculation and bring up the "Results" page.

The button calls up the model selection page for consecutive runs of multiple models. This feature is available for advanced users only.

Warning: using these buttons deletes all existing output from the dose models, in order to ensure consistency in the outputs.

Input parameters

Shield depths

The shielding depths for the dose calculations can be entered in two ways. The required shielding thicknesses can be entered in three ways:

SHIELDOSE and SHIELDOSE-2

Two parameters have to be specified for the ionising dose models: the shielding configuration and the target material. When a shielding distribution input file is used, the shielding is assumed to be spherical, and no selection is presented.

SPENVIS includes an updated version of SHIELDOSE-2 (SHIELDOSE-2Q ) which extends the shielding database behind the model to treat higher energy electrons and different shield and target materials.

Non-ionising energy loss

Optical devices can be susceptible to degradation by exposure to proton irradiation. The degradation is caused by non-ionizing energy loss (NIEL) of protons impacting the device, and is well represented by a damage equivalent proton fluence. This quantity is related to CCD degradation by a damage factor.

Advanced users have the option to define the proton equivalent energy. The default setting is 10 MeV. In addition, these users can select between different damage curves (see References), enter a damage curve in a text box, or upload a damage curve file. The format of the file to be uploaded is a number of two-column lines with energy (in MeV) and NIEL (in MeV cm2 g-1), respectively, preceded by a single header line, e.g.: 
Summers 12.9 eV (1993)	
0.001	15.460107
0.002	10.5300729
0.003	8.09805604
0.005	5.65903916
0.007	4.41303054
0.01	3.36002325
0.02	1.93801341
0.03	1.39000962
0.05	0.90580627
0.07	0.6799047
0.1	0.50030346
0.2	0.27220188
0.3	0.18590129
0.5	0.11940083
0.7	0.08773061
1	0.06381044
2	0.03296023
3	0.02243016
5	0.0137601
7	0.01047007
10	0.00788505
20	0.00536004
30	0.00477803
50	0.00388403
70	0.00316102
100	0.00259802
200	0.00194001
Once a file has been uploaded, it can be used again for a new calculation without having to re-upload it again, or it can be overriden by a new upload.

Results

To generate plots, select the plot type(s), options and graphics format, and click the button. The current page will be updated with the newly generated plot files.

The button calls up the output page for consecutive runs of multiple models. This button only appears when the dose models have been included in the combined model run selection. This feature is available for advanced users only.

SHIELDOSE

SHIELDOSE produces the files listed in the table below. A description of the format of the files can be brought up by clicking on their description in the table.

The report file spenvis_shp.html contains the input parameters and summary tables. The output file spenvis_sho.txt contains the total mission doses for the different particle types.

Output files generated by SHIELDOSE
File name Description
spenvis_shp.html Report file
spenvis_sho.txt Total mission doses

SHIELDOSE-2

SHIELDOSE-2 produces the files listed in the table below. A description of the format of the files can be brought up by clicking on their description in the table.

The report file spenvis_s2p.html contains the input parameters and summary tables. The output file spenvis_s2o.txt contains the total mission doses for the different particle types.

Output files generated by SHIELDOSE-2
File name Description
spenvis_s2p.html Report file
spenvis_s2o.txt Total mission doses

SHIELDOSE-2Q

SHIELDOSE-2Q produces the files listed in the table below. A description of the format of the files can be brought up by clicking on their description in the table.

The report file spenvis_sqp.html contains the input parameters and summary tables. The output file spenvis_sqo.txt contains the total mission doses for the different particle types.

Output files generated by SHIELDOSE-2Q
File name Description
spenvis_sqp.html Report file
spenvis_sqo.txt Total mission doses

Non-ionising energy loss

The NIEL model produces the files listed in the table below. A description of the format of the files can be brought up by clicking on their description in the table.

The report file spenvis_nip.html contains the input parameters and summary tables. The output file spenvis_nio.txt contains the shielded proton spectra and the NIEL curves.

Output files generated by the NIEL model
File name Description
spenvis_nip.html Report file
spenvis_nio.txt Shielded proton spectra and NIEL curves

References

Huhtinen, M., and P. Aarnio, Pion induced displacement damage in silicon devices, Nucl. Instrum. Methods, A 335, 580–582, 1993.

Jun, I., M. A. Xapsos, S. R. Messenger, E. A. Burke, R. J. Walters, G. P. Summers, and T. Jordan, Proton Nonionizing Energy Loss (NIEL) for Device Applications, IEEE Trans. Nucl. Sci., 50, 1924-1928, 2003.

Messenger, S. R., E. A. Burke, M. A. Xapsos, G. P. Summers, R. J. Walters, I. Jun, and T. M. Jordan, NIEL for heavy ions: An analytical approach, IEEE Trans. Nucl. Sci., 1919-1923, 2003.

Summers, G. P., E. A. Burke, P. Shapiro, S. R. Messenger, and R. J. Walters, Damage correlations in semiconductors exposed to gamma, electron and proton radiations, IEEE Trans. Nucl. Sci., 40, 1372-1379, 1993.

P. Truscott, "JORE2M2 Project: SHIELDOSE-2Q Requirements, Interface Control, Design, Implementation and Justification Document," QINETIQ/TS/AS/SDD0900017, 2010.

P. Truscott, "JORE2M2 Project: SHIELDOSE-2Q Software User Manual," QINETIQ/TS/AS/SUM1003576, 2010.

Last update: Mon, 12 Mar 2018