Recent advances in the HL-2A tokamak experiments

Abstract

Two experiment campaigns were conducted on HL-2A tokamak in 2003 and in 2004 after the first plasma was obtained at the end of 2002. Progresses in many aspects have been made, especially in the divertor discharge and feedback control of plasma configuration. Up to now, the following operation parameters have been achieved: Ip = 320 kA, Bt = 2.2 T and discharge duration T d = 1580 ms. With the feedback control of plasma current and horizontal position, an excellent repeatability of discharge has been achieved. The tokamak has been operated at both limitor configuration and single null (SN) divertor configuration. The HL-2A SN divertor configuration is simulated with the MHD equilibrium code SWEQU. The divertor experiment results were compared with the simulation results obtained with B2. When the divertor configuration is formed, the impurity radiation in main plasma decreases remarkably. The plasma performances are improved significantly after siliconization.

Lower Hybrid Current Drive in High Aspect Ratio Tokamaks

“…Like TRIAM-1M and WEST machines, HL-2A is a medium size tokamak characterized by a rather large aspect ratio [31]. With the major radius R = 1.75 m and the minor radius a = 0.35 m, A ' 5.0 during LH current drive experiments, since the plasma is shifted outwards to the LFS in order to minimize the distance between the antenna and the separatrix and improve wave coupling.…”

“…1 is well fulfilled. The case of the full LH current drive in the high aspect ratio tokamak HL-2A [31], for which the spectral gap is much smaller while the excited power spectrum has many lobes, is considered by comparison. In Sec.…”

Experimental investigation of phase equilibria in the Zr–Nb–Cr system at 1573 K and 1373 K

“…Since Nb and Cr have pronounced effects on thermal and physical properties of zirconium alloys [3,4], the examination on the phase diagram of the ZreNbeCr system is essential for providing efficient support when developing high performance alloys and searching for optimized processes in production.…”

The component development status of HL-2M tokamak

“…HL-2A tokamak was put into operation in 2002 [1]. The HL-2A project actually included two steps when it was constructed in 1990s, i.e.…”