文档介绍：Lower Hybrid Current Drive (LHCD) System
1. Subject: Lower Hybrid Current Drive (LHCD) System
Serial No: U202
The purpose of LHCD program
1)Introduction
Lower hybrid waves are quasi-static electric waves propagated in ically confined plasmas. The lower hybrid wave may transfer its energy to electrons by Landau damping, leading to acceleration of the electrons’ motion at the direction along with the wave vector, additional electrical current is thus driven, that is called lower hybrid current drive (LHCD). In tokamak plasmas, the lower hybrid range of frequency is usually within microwave frequency range, therefore, an LHCD system is actually a microwave system that can couple its microwave energy into tokamak plasmas in a lower hybrid mode.
The LHCD system on the HT-7U mainly includes: (1) Microwave generators; (2) high voltage power supply(HVPS); (3) transmission system & antenna; (4) monitor & control system; and so on.
The LHCD system on HT-7U will be used for the following purposes:
(1) To maintain long duration or even steady state plasma current in the tokamak, and supply its energy to the plasma continuously;
(2) To achieve steady state high performance.
2) Background
The studies on LHCD in the world began at the early 1980's. So far most of the large tokamaks have their own LHCD systems, the parameters are listed in the following table:

Name of Device
JET
Tore Supra
JT-60U
TdeV
TRIAM-1M
HT-7
UK
France
Japan
Canada
Japan
China
Microwave power(MW)
12(20s)
15(10s)
8
24
(30s)
3(10s)

No. Of Klysron 与their kinds
24×
TH2103A
16×TH2103
16×E3778
8×LD4444
2×TH2103B
1×TH2075
8×VA876s
12×
KU-
Input power(MW)

6

1

Frequency(GHz)

-

Maximum density
MW/m2
(normal)
36
(20)
38
(25)
21
(13)
50
(25)
11
(4)
65
(47)
17
1020AW-1m-2

Ip[MA]
(Vl=0,
ne1019m-3)
3
()
1.