Beam transport experiment with a new kicker control system on the HIRFL

Abstract

The kicker control system was used for beam extraction and injection between two cooling storage rings (CSRs) at the Heavy Ion Research Facility in Lanzhou (HIRFL). To meet the requirements of special physics experiments, the kicker controller was upgraded. The new controller was designed based on ARM+DSP+FPGA technology and monolithic circuit architecture, which can achieve a precision time delay of 2.5 ns. In September 2014, the new kicker control system was installed in the kicker field, and the test experiment using the system was completed. In addition, a pre-trigger signal was provided by the controller, which was designed to synchronize the beam diagnostic system and physics experiments. Experimental results indicate that the phenomena of "missed kick" and "inefficient kick" were not observed, and the multichannel trigger signals' delay could be adjusted individually for kick power supplies in digitization; thus, the beam transport efficiency was improved compared with that of the original system. The fast extraction and injection experiment was successfully completed based on the new kicker control systems for HIRFL-CSR.

Studies of the hydrodynamic evolution of the dense baryonic matter produced in relativistic heavy ion collisions

“…Indeed, many phenomenological models also predict that a strong first-order phase transition may occur in compressed baryon-rich matter at lower energies [1][2][3][4][5][6][7][8][9], and the purely quark-qluon plasma with zero baryonic chemical potential could be created at high energies ( √ s N N ≥ 13GeV) [10]. Presumably, such dense baryonic matter is created at lower energies ( √ s N N < 10GeV) in the central U-U collisions with beam energies E lab = 0.4AGeV ( √ s N N = 2.07GeV) at the Cooling Storage Rrings (CSR) at the Heavy Ion Research Facility in Lanzhou (HIRFL) [11], the central U-U collisions with beam energies E lab = 1.0AGeV ( √ s N N = 2.32GeV) at High Intensity Heavy Ion Accelerator Facility (HIAF) [12], the central Au-Au collisions ( √ s N N = 2.7 − 4.9GeV) of Compressed Baryonic Matter (CBM) experiment at Facility for Antiproton and Ion Research (FAIR) [13,14], the central Au-Au collisions ( √ s N N < 10GeV) of Multi-Purpose Detector (MPD) experiment at Nuclotron-based Ion Collider fAcility (NICA) [15], and the central Au-Au collisions ( √ s N N = 7.7GeV) of the Beam Energy Scan (BES) program at Relativistic Heavy Ion Collider (RHIC) [16,17]. Especially for the center-of-mass energies √ s N N ≤ 5GeV, the dense baryonic matter is dominated by the incoming nucleons [18,19].…”