1. Date of download: 9/19/2016 Copyright © ASME. All rights reserved. From: Optical Analysis of a Two Stage XX Simultaneous Multiple Surface Concentrator for Parametric Trough Primary and Flat Absorber With Application in Direct Steam Generation Solar Thermal Plants J. Sol. Energy Eng. 2016;138(2):021002-021002-6. doi:10.1115/1.4032243 PTC geometry for circular absorber Figure Legend:

2. Date of download: 9/19/2016 Copyright © ASME. All rights reserved. From: Optical Analysis of a Two Stage XX Simultaneous Multiple Surface Concentrator for Parametric Trough Primary and Flat Absorber With Application in Direct Steam Generation Solar Thermal Plants J. Sol. Energy Eng. 2016;138(2):021002-021002-6. doi:10.1115/1.4032243 PTC geometry for flat absorber Figure Legend:

3. Date of download: 9/19/2016 Copyright © ASME. All rights reserved. From: Optical Analysis of a Two Stage XX Simultaneous Multiple Surface Concentrator for Parametric Trough Primary and Flat Absorber With Application in Direct Steam Generation Solar Thermal Plants J. Sol. Energy Eng. 2016;138(2):021002-021002-6. doi:10.1115/1.4032243 A parabolic primary and a CEC secondary for flat receiver [14] Figure Legend:

4. Date of download: 9/19/2016 Copyright © ASME. All rights reserved. From: Optical Analysis of a Two Stage XX Simultaneous Multiple Surface Concentrator for Parametric Trough Primary and Flat Absorber With Application in Direct Steam Generation Solar Thermal Plants J. Sol. Energy Eng. 2016;138(2):021002-021002-6. doi:10.1115/1.4032243 Second stage concentrator with two asymmetric CPCs on each side, for total rim angle of 90 deg [14,15] Figure Legend:

5. Date of download: 9/19/2016 Copyright © ASME. All rights reserved. From: Optical Analysis of a Two Stage XX Simultaneous Multiple Surface Concentrator for Parametric Trough Primary and Flat Absorber With Application in Direct Steam Generation Solar Thermal Plants J. Sol. Energy Eng. 2016;138(2):021002-021002-6. doi:10.1115/1.4032243 XX SMS optics for circular receiver [19] Figure Legend:

6. Date of download: 9/19/2016 Copyright © ASME. All rights reserved. From: Optical Analysis of a Two Stage XX Simultaneous Multiple Surface Concentrator for Parametric Trough Primary and Flat Absorber With Application in Direct Steam Generation Solar Thermal Plants J. Sol. Energy Eng. 2016;138(2):021002-021002-6. doi:10.1115/1.4032243 Calculating the first portion of the primary [14] Figure Legend:

7. Date of download: 9/19/2016 Copyright © ASME. All rights reserved. From: Optical Analysis of a Two Stage XX Simultaneous Multiple Surface Concentrator for Parametric Trough Primary and Flat Absorber With Application in Direct Steam Generation Solar Thermal Plants J. Sol. Energy Eng. 2016;138(2):021002-021002-6. doi:10.1115/1.4032243 SMS chains for calculating the shape of optical surfaces[14] Figure Legend:

8. Date of download: 9/19/2016 Copyright © ASME. All rights reserved. From: Optical Analysis of a Two Stage XX Simultaneous Multiple Surface Concentrator for Parametric Trough Primary and Flat Absorber With Application in Direct Steam Generation Solar Thermal Plants J. Sol. Energy Eng. 2016;138(2):021002-021002-6. doi:10.1115/1.4032243 XX SMS optics for flat absorber Figure Legend:

9. Date of download: 9/19/2016 Copyright © ASME. All rights reserved. From: Optical Analysis of a Two Stage XX Simultaneous Multiple Surface Concentrator for Parametric Trough Primary and Flat Absorber With Application in Direct Steam Generation Solar Thermal Plants J. Sol. Energy Eng. 2016;138(2):021002-021002-6. doi:10.1115/1.4032243 Angle transmission curve comparison Figure Legend:

10. Date of download: 9/19/2016 Copyright © ASME. All rights reserved. From: Optical Analysis of a Two Stage XX Simultaneous Multiple Surface Concentrator for Parametric Trough Primary and Flat Absorber With Application in Direct Steam Generation Solar Thermal Plants J. Sol. Energy Eng. 2016;138(2):021002-021002-6. doi:10.1115/1.4032243 Proposal of a multitube receiver Figure Legend: