Data processing on application of real- time systems and ... Documents/Fusion... · chord HCN laser interferometer. ... taking advantage of the FIR laser interferometric data as the

HL-2A

Data processing on application of real-

time systems and validation of

diagnostics in HL-2A

Min XU and HL-2A team

Southwestern Institute of Physics, Chengdu, China

2nd IAEA technical meeting on Fusion Data

Processing, Validation, and Analysis

30 May - 02 June, 2017, Cambridge, MA USA

HL-2A

Introduction

─ Real-time system: high desirability for fusion research (e.g.

diagnostics, discharge operation);

[However], challenged (algorithm, hardware, high accuracy…… );

─ Recently, newly developed real-time control systems have been

dedicated to the study of plasma physics studies in the HL-2A tokamak.

2

─ Prominent data processing methods involved:

Real-time FIR interferometer system

Real-time control of tearing mode by ECRH

CODAC framework in HL-2A

Integrated analysis of diagnostics

Langmuir probe sheath potential coefficient

HL-2A

OUTLINE

─ Real-time FIR interferometer system

─ Real-time control of tearing mode by ECRH

─ CODAC framework in HL-2A

─ Integrated analysis of diagnostics

─ Langmuir probe sheath potential coefficient

3

HL-2A

OUTLINE



─ CODAC framework in HL-2A



4

HL-2A

─ HCOOH interferometer-polarimeter was developed and based on the eight-chord HCN laser interferometer.

─ It consists of a four-chord interferometer and a four-chord polarimeter.

─ The interferometer is Michelson type and the polarimeter is Dodel-Kunz type.

Multi-channel FIR Laser Inter-polarimeter

HCOOH

HCOOH

Laser system

Waveguide transmission

Support structure

Inner optical components

The schematic diagram of the HCOOH laser

inter-polarimeter on HL-2A

HCOOH laser

Controller

Temperature monitor

Power

5

HL-2A

Data Processing and Acquisition System

Band-pass filter

Probing beam

Band-pass filter

Reference beam

ADC

FPGA

(fft、ifft)

PXI

DDR-II Module

DAC Control modules

Power-supplymodule

TRIG

CLC

Power-supply module

Density

feedback

control

To HL-2A

database

No.1# No.2#

The schematic diagram of the data

processing system by hardware.

─ Phase-comparator based on the FFT technique is first explored;

─ Signal from DAC is used for the electron density feedback control;

─ Raw signals are collected with a sampling frequency of 6.25MHz;

─ Data can be upload to the HL-2A database in several minutes.

Integrated circuit card Interface of the data

processing system

Data processing and acquisition system

6

HL-2A

Real-time Density Feedback Control─ It is important to control the electron density during the plasma discharge, by taking advantage of the FIR laser interferometric data as the feedback control signal.

─ Experimental results show effective density feedback control using the HCOOH laser interferometric signal on HL-2A.

The typical waveform of the electron density feedback control using the HCOOH laser interferometric data.

Gas puffing

Electron density

Plasma current

7

HL-2A

OUTLINE



─ CODAC Framework in HL-2A



8

HL-2A

Closed Loop Feedback System for NTM Control

R T Tim ing N etw orking

R T D ata S ynchronization N etw orking – R eflective M em ory

RT PARC

Based on GPU& R edhat M R G

RT PARC

Data Acquisition

Based on LabVIEW RT

RT ECE Data Acquisition &

Calculation

Based on LabVIEW RT

RT Mirnov Probe Data

Acquisition &Calculation

Based on LabVIEW RT

Motor Controller

Based on LabVIEW RT

Motor&M irror

Plasma

ECRH

Antenna

ECRH

Generator

E C R H S ystemS ervo S ystem

300 400 500

-1

0

1

dB/d

t (a

. u.)

300 400 5000

100

200

300

PE

CR

H (kW

)

200 300 400 500 6000

0.2

0.4

0.6

t (ms)

Island position

ECRH deposition

#27754

─ RT control of NTMs by ECRH with launcher

mirror steering was developed.

─ An RT code solves equilibrium equation with

129129 grid scale in 1 ms.

─ The magnetic island location has the high

spatial resolution less than 1 cm.

─ Tearing modes were stabilized with the RT

mirror steering.

9

HL-2A

2%

26%

61%

10%

< 1%< 1%

time consumption per slice (us)

~560

560~

570~

580~

590~

600~

FAST Parallel Equilibrium Reconstruction Code Based on GPU

─ Based on RealTime Linux - Redhat MRG

─ Grid resolution: 129*129

─ GPU: NVIDIA Tesla K20

─ One slice computation takes 570us typically

─ Very Small bias comparing to offline EFIT within 1cm

Grid

(0,0)

Grid

(0,1)

Grid

(0,2)

Grid

(0,126)

Grid

(126,126)

Grid

(1,0)

Grid

(1,1)

Grid

(1,2)

Grid

(1,126)

Grid

(2,0)

Grid

(2,1)

Grid

(2,2)

Grid

(2,126)

Grid

(126,0)

Grid

(126,1)

Grid

(126,2)

Idle

Idle

Idle

Idle

...

...

...

...

...

Thread

Block1

Thread

Block2

Thread

Block3

Thread

Block127

...

...

...

...

...

CPU

Thread

Signal Processing

Polynomial

Coefficients

Fitting

Current Density

Profile

Magnetic Flux

Profile

(Grad-Shafranov

Solver)

Magnetic Axis,

X point,

LCFS, etc.

Data

Storage

GPU

PCIe

the computation of one Time Slice

Blue: Offline EFIT

Red：this code

Shot:25557

comparison

10

HL-2A

Real-time Control for TM

─ The RT “ECE/Mirnov” subsystem for localizing NTMs，ECE signals with spatial

resolution of 1 cm.

─ The algorithm finishes within 1 ms and provides the NTM position (rNTM) to the PCS

─ The motor will push the steering mirror to the expected angle. Motor controller to be

run on LabVIEW RT will calculate the motor control signal with all of possible

information from the reflective memory networking.

─ The rotation time of antennae mirrors will be ~ 50 ms.

Steering Antenna

11

HL-2A

OUTLINE






12

HL-2A

CODAC Framework of HL-2Aa Siemens PLC Ring Network used for slow control interlock and safe interlock

─ PLC Ring NetWorking is based on Siemens PLCs :

─ switch，SCALANCE X202-2IRT

─ CPU，CPU416-3PN/DP

─ SOE，6ES7 153-2BA02-0XA1

─ STEP 7，V5.5

─ Wincc，V7.0

Switch

Switch

Switch

Switch

Switch

Switch

EPICSServer

...

Central

Control

PLC

WinCCWorkstation

PowerSupply

PLC

NBI PLCECRH

PLC

PLC5

Generator

PLC

WinCCWorkstation

WinCCWorkstation

WinCCWorkstation

WinCCWorkstation

WinCCWorkstation

OPC to EPICS

WorkStation

EPICSClient

EPICSClient

EPICSClient

EPICSClient

...

Fiber

Fiber

Fiber

Fiber

Fiber

Fiber...

24V DC

OPCServer

─ All of the 8 PLCs in HL-2A are in the Ring Network

─ Information can be shared freely within all PLCs

─ Information can be shared via EPICS outside interlock system

─ PLC nodes can easily added to or deleted from Ring Network without any influences to other PLCs

13

HL-2A

EPICS Networka EPICS network with that all of subsystem can get the authorized information of other subsystems only using a

single protocol without any difficulty

─ There are nearly 8000 Process Variables form various systems exist in HL-2A experiments

─ There are several Servers serve as the infrastructure of the EPICS System in HL-2A

─ One can submit a Process variable only to Process Variable Management System so that the PV

can be shared and managed in the EPICS system

Process VariableManagement

System

CSS/OPI User application

Normal LAN

VPN

CSS/OPI

User application Process VariableManagement

System

Other

Application

Server

EPICS Server

IOC

Linux

SQL Server

Data Storage

SAN

LDAP

Access Control

Domain Server

Alarm Server

SMS, Phone Call

Windows

Vacuum

Power Supply

Fueling

Heating

Netwoking

DCQ

CentralControl

Diagnostic

Fly wheel

Wall Condition

interlock

Cooling

Process VariableManagement System

CSS/OPI

User application

Experiment LAN

14

HL-2A

Reflective Memory(RFM) Networka reflective memory(RFM) network which acts as the fast control network in ITER CODAC for plasma real time

control which act as the SDN in ITER

HL-2A/M

Data Storage Server

LabVIEW fiber

fiber

fiberfiber

Actuator

OH-欧姆线圈

V-垂直场线圈

R-水平场线圈

MP-多极场线圈

MC-MP 补偿线圈

P-无源被动线圈

cable

Experiment Ethernet

LAN

LAN

LAN

RFM HUBRFM HUB

RFM

RT Linux

RFM

r

1z

Ku

N

N

w

M

1M

2z

y

+ -

+

+

+

-

RT Plasma

Shape Control

RFM

RT Linux

RFM

RT shape&

Profile

Reconstructi

on

RFMPower Supply

Control

NI RT

RFM LAN

RFMDigitalI/O

Simple signal process

ing

NI RT

A/D

RT DCQ

RFMDigitalI/O

Simple signal process

ing

NI RT

A/D

RT

Monitoring

RFMSMBI&

Gas Puffing

NI RT

RFMRFMECRH

NI RT

RFM

LAN LAN

fiber

RFM

Windows

RFM

RT

Display

fiber RFM

RT Linux

RFM

RT Profile

Control

fiber

fiber

─ In the networking, there are more than ten GE RFM Cards has being deployed in HL-2A Experiment

for various RT control purpose

─ There are two RT Operating Systems which are NI RT and RT where the RFM Cards work well.

─ RFM nodes for RT Control can easily added to or deleted from RFM Network without any influences

to other Nodes

15

HL-2A

DataBase

server

Streaming media

server

System Administration

Monitor&Configure&Control

Web Browser Web Browser

Web Server

Web Browser

Router

IP Camera&Pickup IP Camera&Pickup IP Camera&Pickup IP Camera&Pickup IP Camera&Pickup

AV management

Server

Storage

Server

TV Wall

AV

Decoder

Web Browser

─ In the AVN, there are more than170 IP cameras&pickups in

HL-2A.

─ A new IP camera join AVN when it connects to the private LAN

─ The real-time Audio &video can be obtained using web browser

personally or can be obtained with a TV wall in the public

AVN for Audio and Video Acquiring and Storage

16

HL-2A

OUTLINE






17

HL-2A

Conventional vs. Integrated data analysis (IDA)

( ) ( )

( ) ( )

e e

e e

n n

T T

Estimates:

Conventional (individual) IDA (probabilistic combination)

Disadvantages:

× (self-) consistent results?

×error propagation

× loss of information about the physics

interdependency

×often backward inversion techniques

Additional

information,

physics

constraint…

Advantages:

✓avoids error propagation

✓uses only forward modeling

✓can easily integrate additional physical

information and improve results

✓result: probability distribution of

parameters of interest

The Goal of IDA:

• replace combination of results from individual analysis

• with combination of measured data from heterogeneous diagnostics (one-

step analysis of pooled data) to improve results.

18

HL-2A

SXR Reconstruction on HL-2A

Physical model:

Matrix formulation:

response matrix represents the

contribution of pixels to lines-of-sight.

emission from all the pixels.

Ill-conditioned:

number of unknowns > number of data

Therefore, it is ill-posed and

the solution needs to be stabilized by

imposing regularization.

( )true

noised R f

M NM Nd R f

M NR

f

Discretization of the emitting area across

the poloidal plasma cross-section

19

HL-2A

MHD Mode Analysis by SXR Reconstruction

─ Relevant measurements of the

MHD instability modes and

frequency spectrum.

@ shot #21589 on HL-2A

─ SXR reconstructions at four

consecutive time points during LLM.

─ strong oscillation

─ displacement of flux surfaces

20

HL-2A

@ shot #21589 at 555.36ms

Spatial-temporal Feature of the LLM

─ Mode structure revealed by

the use of Singular-Value-

Decomposition (SVD).

─ m=1 and m=2 modes are

overlapped on q=1 surface

─ Significance and frequency of

the perturbation modes.

21

HL-2A

OUTLINE






22

HL-2A

Evaluation of Langmuir Probe Sheath Potential

Probe measurement

regionLCFS

Limiter

vacuum

vessel

V- V+

RsRswept

C V1

V2

(a)

(b)

(c)

(d)

Sheath potential coefficient Λ, is a critical coefficient for estimating plasma sheath potential： Vp=Vf+αTe

(a)

(b)

(d)

(c)

(e)

(f)

(g)

Crossing LCFS

turbulence

(h)

Experiment setup:

double tips circuitSwept probe circuit

Ohmic discharge:

23

HL-2A

Basic Methods

I swep

(A

)

0

0.2

0.4

t (ms)

872 873 874 875 876

Vsw

ep

(V)

-400

-200

0

200

400

(a)

(b)

tt

-200 -100 0 100 200

I sw

ept (A

)

-0

0.1

0.2

Vswept

(V)-200 -100 0 100 200

dI s

wept / d

Vsw

ept (a

.u.)

-1

0

1

2

3

Vp-inter

Ise

Vf

Isi

Vp-fit

(c)

(d)

Two methods to measure Vp

three methods to calculate Λ :

1. Traditional method:

2. Calculated by Vp:

3. Calculated by Ise and Isi:

(most credible one)

[1] Popov, Tsv K., et al. Plasma Phys. Control. Fusion 51 065014 (2009).

[2] Druyvesteyn, M. J. Zeitschrift für Physik 64 781 (1930).

24

HL-2A

Equilibrium Case

Profile in Ohmic discharge9 shots’ statistics

α=2.3~2.9

Comparison for Er and its shear

(qualitatively correct)

α

α

α

─ α increase from 2.3 (40mm outside LCFS) to 2.9 (20mm inside LCFS),

─ The traditional αt ==2.8 is qualitatively correct

25

HL-2A

Summary

• A real-time FIR polarimeter/interferometer system has been developed. All

signal processing processes were carried out in the Field Programmable Gate

Array (FPGA) chips. The time resolution can reach to <1 μs.

• The real-time control of tearing mode by ECRH with launcher mirror steering

has been developed on HL-2A. A few real-time diagnostics and intelligent

controllers achieved precise control of ECRH deposition at a rational surface.

• The CODAC Framework of HL-2A has been being established and applied in

HL-2A during the experimental campaigns of 2015 and 2016.

• An integrated analysis of several interdependent diagnostics using Bayesian

probability theory has been developed and applied in HL-2A.It can provide a

joint posterior probability over all the physical parameters..

• The Langmuir probe sheath potential coefficient α was measured in HL-2A

by using 30kHz high frequency swept probe. The α≈2.8 is reliable when

inferring the equilibrium value of Vp .

26