Speaker
Description
X-ray and gamma-ray polarimetry are essential tools for studying the radiation mechanism of high-energy astrophysics. However, there are few such observations. The CMOS is a detector with better spatial and time resolutions compared to CCD. Then, we focused on a small pixel-size CMOS detector IU233N5-Z. That CMOS detector is an optical sensor with 1 million pixels and a small size (1.12×1.12 $\mu$m$^2$). To evaluate the X-ray spectral performance, we irradiated the X-ray sources ($^{55}$Fe, $^{57}$Co and $^{241}$Am) to CMOS at room temperature and obtained values of FWHMs (e.g., FWHM@5.9keV = 180 eV). These are a similar resolution to that of a CCD detector. In addition, from the Fe result, we obtained the depletion layer of the IU233N5-Z as 6 $\mu$m. Also, to evaluate the X-ray polarimetry, we irradiated $^{90}$Sr and observed the electron tracks as long as 30 pixels $\sim30 \mu$m. Furthermore, we beamed the polarized X-ray (15, 30, 50, and 70 keV) at SPring-8. From these measurements, we also observed tracks of the photoelectrons and found the indication of the X-ray polarization from the event directions. In this presentation, we will discuss these results.
| Submission declaration | Original and unplublished |
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