The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions developed by the Institute of Space and Astronautical Science (ISAS), with a planned launch in 2015. The ASTRO-H mission is equipped with a suite of sensitive instruments with the highest energy resolution ever achieved at E > 3 keV and a wide energy range spanning four decades in energy from soft X-rays to gamma-rays. The simultaneous broad band pass, coupled with the high spectral resolution of ΔE ≤ 7 eV of the micro-calorimeter, will enable a wide variety of important science themes to be pursued. ASTRO-H is expected to provide breakthrough results in scientific areas as diverse as the large-scale structure of the Universe and its evolution, the behavior of matter in the gravitational strong field regime, the physical conditions in sites of cosmic-ray acceleration, and the distribution of dark matter in galaxy clusters at different redshifts.
Turbo codes, a partial turbo method and a serial turbo method, were experimentally applied to a Domain Wall Displacement Detection (DWDD) disk using a red laser. An effective bit length of 68nm recording was achieved by a partial turbo method with a parity bit rate of 1/17 at a bit error rate (bER) of 4x10-5 using a maximum a-posteriori probability (MAP) decoder, although a bit length of 80nm was the limit of the conventional partial response maximum-likelihood (PRML) method. It is presumable that the limit of the turbo decoding method for a DWDD disk depends on the number of consecutive 2-bit errors that occur with the disappearance of the 2T pattern. A max-log-MAP algorithm was introduced, instead of the usual MAP algorithm, to implement turbo codes in hardware, and an effective bit length of 69nm was achieved at a bER of 4x10-5.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.