Speaker
Description
At the Research Center for Nuclear Physics (RCNP), Osaka University, the ONOKORO project is underway to systematically investigate cluster knockout reactions. Previous measurements of the Sn(p, pα) reaction have provided experimental evidence for α-cluster formation at the surface of heavy nuclei. In this program, a double-arm spectrometer setup is employed, consisting of the Grand Raiden spectrometer and a large-acceptance spectrometer. The latter is used to detect cluster-emitted particles; however, its optical parameters were not fully determined, necessitating a dedicated optical analysis for optimization.
To establish the optical characteristics of the large-acceptance spectrometer under the same conditions as the main measurements, we performed a calibration experiment using the 12C(p, pα) reaction. The energy calibration on the Grand Raiden side was carried out using elastic scattering of protons from a Pb target. With the energy of the emitted α particles from the 12C(p, pα) reaction being well known, we reconstructed the emission angles at the target by analyzing the focal plane position and incident angle, using the information from a sieve slit placed at the spectrometer entrance.
This procedure enabled the full reconstruction of the α-particle momentum vector. Combined with the momentum of the recoiling proton, the momentum distribution of the α cluster inside the nucleus was derived via momentum conservation. In this poster, we present the optimized optical parameters of the large-acceptance spectrometer and the resulting momentum distribution spectra obtained from the calibration reaction.
| Email address | miyatai@rcnp.osaka-u.ac.jp |
|---|---|
| Supervisor's Name | Junki Tanaka |
| Supervisor's email | junki@rcnp.osaka-u.ac.jp |
| Classification | Ion optics and spectrometers |
