TA Extensions and Future Plans
TA Extensions
TAx4 for the highest-energy cosmic rays
The TA found an evidence for a cluster of arrival directions of highest-energy cosmic rays, which we call the hotspot, We aim at confirming the evidence for the TA hotspot, studing energy, composition, and arrival directions of the highest-energy cosmic rays and elucidaing the nearby supergalactic universe towards quadrupling the TA effective area.(TAx4 in Japanese) The first phase of the TAx4 construction (half of the planned deployment of the surface detectors) finished in February and March in 2019 ([photos by ICRR public relations office]). Now the data of cosmic rays are being collected.
Low energy extension of TA (TALE)
We propose the study of cosmic-ray physics in the energy region between 1016.5eV and 1020.5eV by extending the energy region which TA covers to lower-energy region. It is planned that we deploy an high-density array of surface detectors and atmospheric telescopes with higher elevation, which are designed for TALE partially in the current TA site. By this configuration, we will be able to study the details of energy spectrum, anisotropy, and chemical composition in the lower energy region including the 2nd Knee around 5x1017eV and the ankle around 5x1018eV. We explore the physics of the transition from galactic cosmic rays to extra-galactic cosmic rays and electron-positron pair creation by the interaction of ultra-high energy cosmic rays with cosmic background photons. We compare the interaction of cosmic rays of about 1017eV in the air and LHCf experiment.
Proposal of size extension for the observation of the highest energy cosmic rays on the ground
To study anisotropy and searches for point sources of the highest energy cosmic rays, we propose the high-statistics and high-precision observation by extending the size about 10 to 100 times larger than the current observatory for the highest energy cosmic rays. It allows us to measure the energy spectra, chemical composition and study astrophysics in detail.
- Extension with an surface detector array
- Extension with air fluorescence telescopes
- The JEM-EUSO is the project that includes the observation of cosmic rays beyong 1020eV by mounting a super-wide-angle telescope on the International Space Station (ISS) (joined in December, 2012)
- charge in this project
- PMT calibration
- Onboard calibration
- Test of a prototype of JEM-EUSO project at the TA site (ICRR inter-university research led by Takizawa in Riken)
- The preparation is on-going.