Soft X-ray Polarimeter Concepts
A Narrow-band Approach
The PLEXAS design was proposed to NASA as
a small explorer in 1998. A paper on this approach was presented at the
2002 SPIE meeting.
A Broad-band Approach
Paper (pdf) presented at the SPIE meeting in 2007.
This approach could be used to measure X-ray polarization across
the band from 0.2 to 0.8 keV.
Paper 2 (pdf) was presented at the SPIE meeting in 2008 and
this paper
was presented at the Rome X-ray Polarimetry meeting held in April, 2009.
This approach could be implemented as a small mission or used on
a large mission such as the International X-ray Observatory.
A laboratory for demonstrating critical components of this design
is also described. A small scale version of the laboratory work was
developed in the summer of 2009.
Examples of targets for both instruments:
- BL Lac Objects with relativistic, magnetized jets which
should be polarized up to 60 %
- Isolated pulsars such as PSR 0656+14, which have a strong magnetic
field which will polarize the surface emission at the 20-50% level
- Quasars and Active Galactic Nuclei (AGN) whose disks will show
polarized emission due to electron scattering up to 12%
A Recent Presentation:
See this
pdf for a presentation to the 3rd Galileo-Xu Guangqi meeting in Beijing,
2011. The presentation includes some information about the
GEMS project as
well as a design for a soft X-ray polarimeter and progress in the lab
at MIT where we are testing components that could be used in such a
soft X-ray polarimeter.
Updated: October 23, 2011