f p orsitto enea1 diagnostics for hybrid reactors francesco paolo orsitto enea fusion technical unit...

F P Orsitto ENEA 1

Diagnostics for hybrid reactors

Francesco Paolo Orsitto ENEA FUSION Technical Unit

C R Frascati(Italy)

FUNFI VARENNA 2011

Outline

Hybrid reactor (HR) models considered and their characteristics: relation to ITER and relevance for DEMO

HR : a small,low power DEMO with a (more) complex blanket( fusion + fission) .

Criteria determining the diagnostic systems needed for HRClassification of Diagnostic systems:i) machine protection;ii)

basic plasma control (incl. DT reaction );iii)divertor control;iv) diagnostics for blanket (neutron source and transuranic burn)

Requirement on measurements Technology / R&D needed Conclusion and further work

F P Orsitto ENEA 2FUNFI Varenna 2011

References and contribution

W M Stacey Fus Sci & Tech 2007(SABR design)M Kotschenreuter Fus Eng Des 2009(ST design)M Wang Fus Eng Des 2010 ( Blanket FDS)Y Wu IAEA Conference Geneva 2008 (paper FT/P3-21)

Contributions M Angelone , M Pillon for diamond detectors detectors M Ciotti,J Manzano, F Crisanti, A Botrugno for useful and

lively discussions


Tokamak Hybrid reactor (HR) models


FDS-I China design


FDS-1 model

Georgia Model –SABR


Tokamak major radius R0=3.75-4 mTokamak high aspect ratio A=3.4-4 ( higher than ITER A=3)Medium magnetic field B=5-6T (like ITER)Medium-High current IP=6-8MA( 0.5*IP ITER)Relatively low norm beta N=2-2.8(like ITER)HIPB98 =1-1.1Main scenario : H-mode Pulsed mode Q=Pfus/Pheating=3 ( Q ITER =5-10)

Comparison between FEB/FDS-I (EM) and SABR


Comparison between Hybrid Reactor(HR) and ITER & relevance of HR to DEMO

The Q_HR factor is of the order of 5-7 times that possible on JET at present And about ½- 1/3 of Q-ITER.

Q_HR = 5-7 Q_JET

Q_HR = ½-1/3 Q_ITER

Q_HR is intermediate between JET and ITER

Difference of HR with respect to ITER is the availability : 75% is supposed for HR While for ITER presently it’s 4%.

The HR Tokamak can be considered a prototype at small scale of DEMO

The HR availability is that hypotesized for a small ( R0=3m) , LOW Q (low performance) DEMOWith a complex blanket: FUSION + FISSION


Criteria determining the diagnostics needed for Hybrid

F P Orsitto ENEA FUNFI VARENNA 2011

Tokamak as neutron source

The plasma scenario is supposed assessed : no measurements dedicated to physics /scenario evaluationThe engineering would permit the insertion of DIA for scenario ev.If needed.

The measurements ARE NEEDED for1. the CONTROL of the scenario ( including DT reactions and neutron production)2. the safety of the device ( including the divertor and PWI)3. Monitor the Blanket Modules dedicated to the tritium breeding

Criteria determining Diagnostics needed for Hybrid Reactor(HR)

F P Orsitto ENEA FUNFI VARENNA 2011

HR as neutron source for fission The measurements ARE NEEDED to monitor 1. the fission of Main transuranic(TRU) elements2. the secondary ( from fission) neutron production 3. energy production from fission

ITER assessed Diag Plan


An example of DIA set for tokamak : Diagnostics of JT-60SA


An example of control plan :Control plan JT-60SA


Tokamak/neutron source measurements and diagnostics

Tab I Tokamak Diagnostics

machine protectionBasic-plasma measurements basic plasma diagnostics

neutron monitors line average electron densityInterferometer/polarimeter

Neutron activation measurements fusion power neutron monitors

D emission monitors Zeff measurementsbrehmsstrahlung rad meas

Divertor Langmuir probes impurity and D,T influx Infrared TV camera(divertor) resistive wall mode magnetic loopsrunawys electrons Halo current magnetic loops nT/nD in plasma core divertor erosion monitors QMB/Monitor Tiles Gas pressure (divertor and ducts) electron temperature

ECE / Thomson scattering using Nd:YAG

Dust plasma radiation bolometers surface temperature( divertor and first wall) plasma shape and position

plasma current F P Orsitto ENEA 14FUNFI Varenna 2011

Tokamak/neutron source Control Plan

Tokamak/neutron source Control Plan quantity to be controlled actuators Sensors/diag systemsplasma position poloidal field coils magnetic pick-up coilsplasma shape in vessel coils flux loopsplasma current poloidal field coils Rogowsky coils

electron densitygas puff, pellet injector,divertor pumping Interferometer

Neutron emission rate P-NB (ECRH , LHCD) Neutron monitorPlasma stored energy P-NB (ECRH,LHCD) Diamagnetic loopDensity profile Pellet , gas puff InterferometerCurrent profile P-NB (ECRH,LHCD) PolarimeterRadiation power Impurity gas puff BolometerFusion power P-NB, gas-puff,pellet (ECRH,LHCD) Neutron monitorTemperature P-NB (ECRH,LHCD) ECE for Te


Blanket modules example from China FDS(*)

Y Wu Fusion Engineering Design 2006

FDS I Hybrid Blanket design General scheme of a blanket for hybrid

M Wang Fusion Engineering Design 2010


Proposed scheme of blanket

F P ORSITTO (ENEA) 17FUNFI VARENNA 2011

Isotopes and decays element Mass Nr

alpha decay(kev) gamma decay(keV) Half life

Am 2435233.3 74.6647370y 5275.5 43.533 5181.1 Pu 2424856.2 44.9153.733e5y 4900.5 Pu 2395105.5 24000y 5111.2 5144.3 5156.59

Np 2374788.0 29.37

2.144e6 y

4771.0 86.477 4766.0

Pa 2315013.8 27.36 32760y

5028.4 5058.6


Blanket diagnostics

The blanket diagnostics need for measuring :

i)The content of isotopes ( measurement alpha lines of various radionuclides)ii)The neutron multiplication ( neutron flux / neutron spectroscopy)iii)Tritium breeding ( monitors of tritium)

Sensors can be inserted in the :i)FUEL zoneii)Tritium breeding zone iii)Outside the vessel


Meaurement of Isotopes

The measurement of isotopes can be carried out both :i)Using alpha particle monitors inserted into the blanket very close to the containers of ling life isotopes to monitor on line the ‘transmutation’ of long lived isotopesii) Using off-line alpha particle spectroscopy

Sensors for alpha particle detection and spectroscopy in the range of4-5MeV can be syntetic diamond diodes with technology and electronics Well known and tested These diodes have also a very good resistence to the high neutron flux


Neutron and gamma ray measurements

Sensors for neutron can be inserted into the blanket in particular in the fuel zone As well as outside the vessel

The technology for this detection is well known

The gamma spectroscopy in particular made using high resolutionMeasurements by Ge detectors can be useful to characterize bothPlasma and secondary gamma derived from decay of radionuclides.


Parameters important for determining

the requirements on measurements Neutron flux Q=3 , Pheating =50MW , A=4 and R0=3m

2

218

1219

220

2

/7.2

)/(102.1*

)5/4(

150*

1024.2106.1*14

4.442

mMWPnLoadWallNeutron

smneutronsSEn

PfusNFluxNeutron

MWPheatingQPfusPowerFusion

JMeVEnEnergyNeutron

mA

RSsurfaceTokamak


Requirements on measurements

F P Orsitto ENEA FINFI VARENNA 2011

requirement on measurements for diagnostics of hybrid reactors Tokamak Neutron source

measurement range (keV)spatial resolution

time resolution

accuracy system

temperature 0.01-30 a/10 1Hz 10-20%

ECE & LIDAR Thomson scattering

density 1-20 10 E19 m-2 line integral 1Hz 10-20%

CO2 interferometer

neutron flux and emissivity

10 E14-10 E20 n/s integral 1Hz 10%

diamond detectors

neutron profile monitor

10 E14-10 E19 n/(m2 s)a/10 1Hz 10%

diamond detectors or scintillators

Zeff monitor line integral 1Hz 10%

vis bremmsthralung

escaping alpha <2MW/m3

a/10 along poloidal direction 100ms 10%

scintillator probe

Requirements on measurements

F P Orsitto ENEA FuNFI VARENNA 2011

divertor operational parameters divertor termography

200-3000 C 1Hz 10%

erosion rate 1-10E-6 m/s 10mm 1s 30%

Gas pressure 1E-4-20Pa

50ms 20%

blanket ( Fuel zone)

alpha particle 4-5MeV integral 1Hz 10%diamond detectors

(off line and inside measurements)

gamma ray 10-100keV integral 1Hz 10%

Ge detectors

(off line measurements)

DIA for Hybrids :R&D Needs

Tokamak /neutron source :

Erosion of divertor

Lost alpha probe

Blanket : Fuel Zone Test of Diamond detectors asAlpha particle diagnostic inside


conclusions

F P Orsitto ENEA

Tokamak for Hybrid concept is located between ITER and a low power proto-DEMOHR Tok :Q=3, availability 75%, long pulses (months?) ITER: Q=5-10, pulse duration 400s, availability 4%

Diagnostics for hybrid share some characteristics with a low power proto-DEMO Diagnostic system:• No scenario evaluation ,• monitor of main kinetic quantities,• control of MHD Stability and current profile via Current Drive• Diagnostics for the safety of the machine( Divertor erosion monitor)

Diag systems can be used also to monitor the FUEL zone of the blanketThrough the measurements of alpha decay of long term actinides

f p orsitto enea1 diagnostics for hybrid reactors francesco paolo orsitto enea fusion technical unit...

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