22nd joint workshop on electron cyclotron emission (ECE) and electron cyclotron resonance heating (ECRH)

Session

Technology-related (Oral)

25 Apr 2024, 09:00

Royal Ball Room (Ramada Hotel, Daejeon, Republic of Korea)

9. Fabrication and Assembly of the Gyrotron Multistage Depressed Collector Prototype at KIT

Mr Benjamin Ell (Karlsruhe Institute of Technology (KIT))

25/04/2024, 09:30

Technology

In this paper the successful fabrication and assembly of the Multistage Depressed Collector (MDC) prototype developed at KIT for megawatt-class gyrotrons is described. The collector design bases on the application of the E×B drift concept for electron trajectory separation, a method that has been presented in [1-3]. The MDC prototype has a cylindrical structure with a helical isolation cut...

68. Beam current feedback control for long pulse operation of the ITER gyrotron

Takahiro Shinya (National Institutes for Quantum Science and Technology)

25/04/2024, 09:50

Technology

For long pulse gyrotron operation, the beam current of the gyrotron must be maintained at a target with high accuracy. In conventional method, the beam current has been adjusted with a pre-programmed control of the heater voltage to the cathode. The reason for changing the heater voltage during the pulse is to warm up the cathode as it cools down due to electron emission. This method requires...

32. The ECH 10-Gyrotron System at the DIII-D Tokamak

Nikolai de Boucaud (General Atomics)

25/04/2024, 10:10

Design

The ECH gyrotron system at DIII-D currently consists of six 110-GHz Communications and Power Industries (CPI) diode tubes available for operation in the 2024 experimental campaign. The RF power is injected into DIII-D via four dual launchers (built by Princeton Plasma Physics Laboratory) located above the mid-plane of the machine. Eight existing transmission lines route from the four dual...

2. Progress on the EU contribution to the EC HCD system of ITER

Ferran Albajar (Fusion for Energy)

25/04/2024, 14:30

Technology

The Electron Cyclotron Heating and Current Drive system (EC HCD) plays a crucial role in all different plasma phase operations to achieve the objectives of ITER.
The European contribution to the ITER EC HCD system includes the procurement of the main part of the HV power supplies, six gyrotrons, all four upper launchers, all the ex-vessel waveguides, and the plant control system. It also...

64. KSTAR ECH System Development Progress

Mi Joung (Korea Institute of Fusion Energy)

25/04/2024, 14:50

Technology

To ensure advanced operation of KSTAR, KSTAR ECH power has been increased since 2017. ECH system was designed so that each ECH system has a source power of 1 MW and operates independently with its own individual power supply and transmission line and launcher [1]. To date, four 105/140 GHz dual frequency and one 170 GHz Russian gyrotrons have been installed and operated, out of a total 6 MW...

57. Results of Frequency Stabilization of a MW-Class Gyrotron at W7-X for the CTS Diagnostic during OP 2.1

Laurent Krier (Max Planck Institute for Plasma Physics)

26/04/2024, 09:30

Diagnostics

At the Wendelstein 7-X (W7-X) stellarator, a Phase-Locked-Loop (PLL) system has been implemented to stabilize the frequency of megawatt-class gyrotrons. The PLL system actively controls the accelerating voltage of the diode-type Magnetron Injection Gun (MIG) to counteract any unwanted frequency changes of the gyrotron output millimeter-wave beam. The accelerating voltage, which is applied...

43. Recent additions to the PROFUSION code for the spurious mode analysis of the ECRH launchers for ITER

Burkhard Plaum (University of Stuttgart)

26/04/2024, 09:50

Technology

In high power millimetre wave transmission systems, even small unwanted effects can have an impact on the system functionality. Therefore, a precise knowledge of the fields and loss mechanisms for realistic scenarios is required during the design phase. An important issue is the
effect of higher order modes (HOMs) on the performance of the equatorial and upper ECRH launchers for ITER. The...