ITPA-Moscow 060410 Role of neutron emission spectrometry on ITER and instrumental requirements Göran Ericsson E.Andersson Sundén, A.Combo 2) , S.Conroy, N.Cruz 2) , M.Gatu Johnson, L.Giacomelli, W.Glasser, G.Gorini 1) , C.Hellesen, A.Hjalmarsson, J.Källne, R.Pereira 2) , E.Ronchi, H.Sjöstrand, J.Sousa 2) , M.Tardocchi 1) , and M.Weiszflog Uppsala University [EURATOM-VR], Uppsala Sweden 1) Univ. of Milano-Bicocca and Istituto di Fisica del Plasma [EURATOM-ENEA/CNR], Milan, Italy 2) Instituto Superior Técnico [EURATOM-IST], Lisboa, Portugal. 1 CONTENTS OF PRESENTATION 1 Introduction 2 ITER parameters from n spectrometry 3 Examples of n spectrometry results 4 NES capabilities (single sight-line) 5 LOS and interface considerations 6 Conclusion
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ITPA-Moscow 060410 Role of neutron emission spectrometry on ITER and instrumental requirements Göran Ericsson E.Andersson Sundén, A.Combo 2), S.Conroy,
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ITPA-Moscow 060410
Role of neutron emission spectrometry on ITER and instrumental requirements
Uppsala University [EURATOM-VR], Uppsala Sweden1) Univ. of Milano-Bicocca and Istituto di Fisica del Plasma [EURATOM-ENEA/CNR], Milan, Italy2) Instituto Superior Técnico [EURATOM-IST], Lisboa, Portugal.
1
CONTENTS OF PRESENTATION
1 Introduction
2 ITER parameters from n spectrometry
3 Examples of n spectrometry results
4 NES capabilities (single sight-line)
5 LOS and interface considerations
6 Conclusion
ITPA-Moscow 060410
1 Neutron diagnostic systems and functions
Neutron diagnostics based on measurement of:
• Neutron inclusive flux: n
• Neutron collimated flux: Fn
- cameras for neutron emission tomography - neutron emission spectrometry
Direct (d) and in-direct (s, scattered) neutron flux components at detector
n= d + s and Fn= Fd + Fs
Neutron diagnostic systems – multi-parameter measurements:
• Fission chambers + activation foils
• Cameras: RNC + VNC
• Cameras + spectrometer
• Systems of spectrometers
Recent progress spectrometers - Europe:
• Two new n spectrometers operating at JET – TOFOR, MPRu (UU/VR)
• Unfolding techniques and detailed calibration of NE213 (ENEA, PTB)
• JET-EP2 – programs on compacts and digital electronics (ENEA, IST)
• “Study of Neutron Spectrometers for ITER”, J.Källne (UU/VR) 2
ITPA-Moscow 060410
2. Potential information in high power DT : neutron emission spectroscopy + camera
(b) Population with significant supra-thermal (ST) velocity components; as above but(1) up to 4 ST reaction rate components (RST) besides RT
(2) relative densities of ST velocity components(3) TT and TST temperatures (if Maxwellian, otherwise slowing down)
B. Confined -particles (1) amplitude of slowing down distribution*(2) pressure
C. Collective motion of fuel ion populations(1) toroidal rotation*
D. Fusion parameters(1) power Pf *; will provide values for dd and dt reactions separately
(2) division of Pf into thermal and supra-thermal components
(3) fuel ion densities in the core (nd, nt and nd/nt*)+)
E. Other information(1) the extended spectrum of direct and scattered neutrons from the plasma
_____________________________________________________________________________________* Denotes diagnostic functions listed as essential for measurement on ITER +) Requires simultaneous measurement of 2.5-MeV neutrons from dd and 14-MeV from dt.
ITPA-Moscow 060410
3 Some selected NES results from JET (MPR)
• Ohmic phase – thermal Ti extracted• RF phase – isotropic, anisotropic HE components
• LE component due to scattered n
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Peak (energy) shift shown in pulses with different phasing of RF antenna
Alpha knock-on neutrons
102
103
104
105
0
4
8
(a)
Cn [H
z]
PN
B [MW
]
PNB(D)
PNB(T)
Cn
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
12 13 14 15 16
ST, MPRTRANSP
Spe
ctra
l fra
ctio
n
Time [s]
(b)
Count rate power
Spectral components thermal fraction
ITPA-Moscow 060410
102
103
104
105
0
4
8
(a)
Cn [H
z]
PN
B [MW
]
PNB(D)
PNB(T)
Cn
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
12 13 14 15 16
ST, MPRTRANSP
Spe
ctra
l fra
ctio
n
Time [s]
(b)
Count rate power
Spectral components thermal fraction
ITPA-Moscow 060410
Alpha knock-on neutrons
ITPA-Moscow 060410
Peak (energy) shift shown in pulses with different phasing of RF antenna
Alpha knock-on neutrons
102
103
104
105
0
4
8
(a)
Cn [H
z]
PN
B [MW
]
PNB(D)
PNB(T)
Cn
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
12 13 14 15 16
ST, MPRTRANSP
Spe
ctra
l fra
ctio
n
Time [s]
(b)
Count rate power
Spectral components thermal fraction
ITPA-Moscow 060410
4 NES capabilities (single sight-line)
• Energy calibration: Independent and absolute calibration station For toroidal rotation vtor < 10km/s
E < 3 keV
• Energy resolution (instrumental, derived, …)For temperature Ti = 4 keV
dE/E = 2.5%
• Sensitivity (S:B)For AKN, RF, TBN S:B > 10000
• Time resolution in derived quantities (Ccap, LOS, )For Ti(t) t < 10 msFor Qth/Qtot t < 200 ms
• Separate direct and scattered fluxE range, low-En sensitivity benchmarking of n transp. calc.
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Magnetic proton recoil
• System in operation at JET• Classic nuclear physics instr.• Separate tasks: passive n-to-p, passive E det., active p counting• f(En) from f(xp)• Near-Gaussian response function• Abs. calibration in E and • Flexibility, 1 < En < 18 MeV• Separate Fd and Fs, E bite 20%• dE/E = 2.5%, E < 2 keV (10-4)• S:B > 10000• Ccap > MHz• t < 5 ms (for Ti) @ 1 MHz• Size (>m3), magnetic, efficiency (0.5.10-4 cm2)
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MPR instrumental response function (2.5% FWHM @ 14MeV)
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Magnetic proton recoil
• System in operation at JET• Classic nuclear physics instr.• Separate tasks: passive n-to-p, passive E det., active p counting• f(En) from f(xp)• Near-Gaussian response function• Abs. calibration in E and • Flexibility, 1 < En < 18 MeV• Separate Fd and Fs, E bite 20%• dE/E = 2.5%, E < 2 keV (10-4)• S:B > 10000• Ccap > MHz• t < 5 ms (for Ti) @ 1 MHz• Size (>m3), magnetic, efficiency (0.5.10-4 cm2)
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Neutron detector test and calibration station:• MPRw: A w-detector can be developed to improve the time resolution and
dynamic range of the diagnostic in, e.g., yield measurements.
• MPRx: A test/calibration facility for flux detectors in well-characterized Fn(En)MPR
• High-performance n spectrometer of MPR type:• State of the fuel ions: Ti, ST comp., AKN, vrot, …• Absolute, independent yield determination, Qth/Qtot
• Absolutely calibrated (E,) n detector test station• Scattered n flux for n transport calc. benchmarking
• Interface issues, magnetics
THANK YOU !
ITPA-Moscow 060410
Summary prel. capabilities and requirements @ 14 MeV
MPR TOF14 NDD NE213 ”Required”
Designed system
Conceptual design
Best achieved
Best achieved
Ccap >MHz 50 kHz > MHz 250 kHz N/A
dE/E 2.5% 2.5% 2% 1-2%* <2.5%
(cm2) 0.5.10-4 1.10-2 1.10-4 0.1 N/A
E < 2keV ? ? ? <3 keV
S:B >10000 100 ? 50 >10000
t (Ti) 5 ms 100 ms 5 ms? 250 ms <100 ms
E range 1-18 MeV >10 MeV? >13 MeV 1-18 MeV§ 1-18 MeV
Separation dir. – scatt.
Yes Yes? No? No? Yes
* Derived from unfolding, not instumental as for others
§ Single peaks, prob. not weak (%) LE components
ITPA-Moscow 060410
TOF-14
• Coincidence measurement, n double scattering• Near-Gaussian resp. fcn• f(En) from f(tn’)• Calibration with gammas, muons, sources• High efficiency, 0.01 cm2 ? (14 MeV) @ dE/E = 2.5%• Ccap = 50 kHz (14 MeV) ?• Signal:accidentals = 100 (sensitivity)• t < 100 ms (for Ti)
• Detector in n ”beam”• Full En deposited: 12C(n,)9Be• Radiation hard, high T oper.• dE/E > 2%• Ccap = MHz• Complicated resp fcn - 9Be*, 12C(n,n), (n,3 n’)• f(En) from f(Q)• Individual detector calibration• Small size, low efficiency • Limited experience base