Current Status of DNB and CXRS on HT-7

DNB team2011-05-07

Overview

• Introduction of DNB and CXRS– Current status– Problems and potential solutions

• Experimental Results– Ohmic discharge– LHCD discharge

• Conclusions

DNB & CXRS

DNB status• Stable and reliable – HV power supply, Ion

source, neutralizer, cryogenic pump, vacuum• Can operate on each plasma discharge if the rest

time is sufficiently long• System capability

– HV: 43~45kV;– Extracted beam current: 4.5 – 5.5A; – Full energy H component: ~20%

• Information on beam power profile and beam divergence angle NOT available

DNB status

653 654 655 656 657 658 659 6601500

2000

2500

3000

3500

E: 19.5%

E/2: 35.4%

E/3: 13.6% E/18: 31.5%

ION-HV:40.7kV

/nm

Intensity

DNB #13749

CXRS status• CX signal of carbon C-VI (n=8->7) transition at 529.1nm in

second order• McPherson 207 spectrometer

– 1200g/mm, Resolution: 0.03nm/331.3nm, Dispersion: 1.24nm/mm

• New Princeton Instrument ProEM EMCCD– 512*512 (16*16um); 95% peak Q.E.; Adjustable gain of electron

multiplication for low-intensity lights(1-1000)• Problem: very small change in CXR signal with DNB

injection • Solution: two discharges with nearly identical parameters

– One without DNB injection to be used as background signal– A large EM avalanche gain for signal enhancement (100)

Ohmic discharge

Ohmic discharge • HV=45kV, Ibeam=5.5A

528.6 528.7 528.8 528.9 529 529.1 529.2-500

0

500

1000

1500

2000

2500shot 111573 channel =4：

wavelength(nm)

Sig

na

l In

ten

sity

261.3775 ( 212.3864—315.1763 )(ev)

束未注入束注入

CXRS束注入CXRS信号高斯拟合信号

528.6 528.7 528.8 528.9 529 529.1 529.2-500

0

500

1000

1500

2000shot 111573 channel =2：

wavelength(nm)

Sig

na

l In

ten

sity

266.9081 ( 218.6056—319.776 )(ev)

束 未 注 入束 注 入

CXRS束 注 入CXRS信 号 高 斯 拟 合 信 号

Ohmic discharge • HV=45kV, Ibeam=5.5A

Ti-111573

LHCD discharge

LHCD discharge

528.6 528.7 528.8 528.9 529 529.1 529.2 529.3 529.4-200

0

200

400

600

800

1000

1200

1400shot 111565 channel =2：

wavelength(nm)

Sig

na

l In

ten

sity

353.0709 ( 295.7745—415.2358 )(ev)

束未注入束注入

CXRS束注入CXRS信号高斯拟合信号

• HV=43kV, Ibeam=4.9A

Ti-111565

Conclusions• DNB & CXRS are working properly

– Use two-identical-shot technique and a large EM gain to improve signal strength

– May contain relatively large uncertainty• Potential improvement

– Beam quality (Full energy H fraction, HV, Ibeam, beam focusing)

– Use CCD’s larger EM gain (larger noise)– Plasma parameter (higher ne?)– More experiments under ICRF heated discharges

Thank you all&

Have a nice day!