DT Polarization for ICF
This presentation is the property of its rightful owner.
Sponsored Links
1 / 27

DT polarization and Fusion Process Magnetic Confinement Inertial Confinement PowerPoint PPT Presentation


  • 134 Views
  • Uploaded on
  • Presentation posted in: General

DT Polarization for ICF. DT polarization and Fusion Process Magnetic Confinement Inertial Confinement Persistence of the Polarization - Polarized D and 3 He in a Tokamak - DD Fusion induced by Laser on polarized HD The “Few-Body” Problems Static Polarization of HD

Download Presentation

DT polarization and Fusion Process Magnetic Confinement Inertial Confinement

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Dt polarization and fusion process magnetic confinement inertial confinement

DT Polarization for ICF

  • DT polarization and Fusion Process

  • Magnetic Confinement

  • Inertial Confinement

  • Persistence of the Polarization

    - Polarized D and 3He in a Tokamak

    - DD Fusion induced by Laser on polarized HD

  • The “Few-Body” Problems

  • Static Polarization of HD

  • Dynamic Polarization of HD and DT

  • POLAF Project at ILE (Osaka)

  • Conclusion

J.- P. Didelez


Dt polarization and fusion process magnetic confinement inertial confinement

95% – 99%

S = ½

S = 1

S = 3/2

S = ½

D + T → 5He (3/2+) → 4He + n

1% – 4%

3/2

1/2

S = 3/2

4 states

-1/2

2/3 of the interactions contribute

to the reaction rate

-3/2

1/2

2 states

S = 1/2

-1/2

50 % Increase

in released energy

  • If D and T are polarized then - all interactions contribute

  • n and αhave preferential directions Sin2(θ)

  • n from DD fusion are suppressed QSF (Jülich – Gatchina)

DT polarization and Fusion Process

(Kulsrud, 1982)

(More, 1983)

D + T → 4He (3.5 Mev) + n (14.1 MeV) + 17.6 MeV

(3.37 1011 J/g)

The question is to know if the polarization will persist in a fusion process ?

Depolarization mechanisms are small:

1) Inhomogeneous static magnetic fields, 2) Binary collisions,

3) Magnetic fluctuations , 4) Atomic effects


Dt polarization and fusion process magnetic confinement inertial confinement

Fusion by Magnetic Confinement – (ITER)

Plasma Density n = 1014 (cm-3) ; Confinement Time τ = 10 (sec)

Lawson Criterion (n τ > 1015 (sec/cm3)

ITER

Plasma Volume = 873 m3

τ = 300 (sec)

Power = 500 MW


Dt polarization and fusion process magnetic confinement inertial confinement

Fusion by Inertial Confinement – (MEGAJOULE)

Plasma Density n = 1026 (cm-3) ; Confinement Time τ = 10-10 (sec)

Lawson Criterion (n τ > 1015 (sec/cm3)

ICF

Target 3mm radius

Carbone &

4 mg cryogenic DT

2000 times compressed

300 g/cm3

5 keV

825 MJ within 100 ps

J. MEYER-TER-VEHN, Nucl. Phys. News, Vol 2 N° 3 (1992) 15


Dt polarization and fusion process magnetic confinement inertial confinement

At fixed G: EB / EA < 0.7

for G=100 EA = 880 kJ

EB = 510 kJ

EAmin = 450 kJ

EBmin = 290 kJ

for E = 1 MJ GA= 140

GB= 307

A:unpolarized DT

B:polarized DT


Dt polarization and fusion process magnetic confinement inertial confinement

DD

D2T2

?

DT

D2 T2


Fusion by magnetic confinement iter

Persistence of the Polarization

Fusion by Magnetic Confinement – (ITER)

- Injection of Polarized D and 3He in a Tokamak (A. Honig and A. Sandorfi)

D + 3He → 4He + p + 18.35 MeV

(DIII-D Tokamak of San Diego, USA)

Expected: 15% increase in the fusion rate

  • Powerful Laser on a polarized HD target → P and D Plasma

  • P + D → 3He + γ + 5.5 MeV

  • Expected: Angular distribution of the γ ray

  • Change in the cross section

  • D + D → 3He + n + 3.267 MeV

  • Expected: Change in the total cross section

  • Sin2θ angular distribution of the neutrons


Dt polarization and fusion process magnetic confinement inertial confinement

Tentative Set-Up

Polarized HD Target

25 cm3

H (p) polarization > 60%

D (d) vect. polar. > 14%

5.5 MeV γ ray from

p + d → 3He + γ

2.45 MeV n from

d + d → 3He + n

Powerful Laser (Terawatt)

creates a local plasma

of p and d ions (5 KeV)

200 mJ, 160 fs

4.5 µm FWHM

970 nm, ~ 1018 W/cm2


Dt polarization and fusion process magnetic confinement inertial confinement

The “Few-Body” Problem

dσ4/dωγ ~ (1+ cos2 θ)* (S = 3/2)

σ0 (10 keV)= 18 µbarn **

1 - 10 radiative captures/laser shot ?

For polarized plasma, angular dependence relative to the polarization axis, but forward peaked, small cross section and almost impossible to detect the γ (EM background).

dσ5/dωn ~ sin2 θ*** (S = 2)

σn5 /σ0 < 0.5 ; σ0 (1.5 MeV)= 100 mbarn ***

For polarized plasma, angular dependence perpendicular to the polarization axis, large cross section and “easy” detection of the very slow neutrons.

Possibility to rotate the polarization of the RCNP HD target without any other change.

High “D” polarization possibleby AFP.

γ

d

d

p

3He

1

1/2

HD Plasma

5 keV

3He

n

d d

*M. Viviani ** G. J. Schmid PR C52, R1732 (1995) *** A. Deltuva , FB Bonn (2009)


Dt polarization and fusion process magnetic confinement inertial confinement

POLAF proposal (RCNP, ILE and ORSAY) with themulti-detector “MANDALA” at ILE - Osaka .

ΔE

ΔE

f10 cm

Count

Count

BC-408 scintillator

t10 cm

PMT

×422 ch

DD neutron energy [MeV]

DD neutron energy [MeV]

Target Chamber

Target Chamber

13.42 m

13.42 m

D~2.2m

D~2.2m

neutron detector

neutron detector

MANDALA

MANDALA

An energy resolution of 28 keV for 2.45-MeV DD neutrons is achieved with MANDALA.

An energy resolution of 28 keV for 2.45-MeV DD neutrons is achieved with MANDALA.


Dt polarization and fusion process magnetic confinement inertial confinement

Static Polarization of HD

B/T > 1500

Dilution Refrigerator 10 mK and 17 T (B/T = 1700)


Dt polarization and fusion process magnetic confinement inertial confinement

Static Polarization of HD :DR 10 mK, 17 T solenoid

1K Pot

1220mm

538mm

Mixing

Chamber

Null Coil

170mm

70mm

Correction Coil

550mm

Main Coil

NbTi joints

&

Switch

Nb3Sn joints

&

Protection Circuit

600mm

Rough dimensions of the magnet

400mm


Dt polarization and fusion process magnetic confinement inertial confinement

Dynamic Polarization of HD or DT

~50%

Transitions made possible

through microwave excitation: ~70GHz

~50%

Adding free electrons. For B=2.5 T and T = 1 K, e- polarization = 92%

B

~50%

92%

Solem et al. in 1974

reach 4% H polarization

with HD containing 4 - 5 % H2 D2

e-

~50%

e-

Proton or Triton

Initial concentration Needed

o-H2: < 0.02 %

p-D2: < 0.1%

Protonrelaxation time >> electron


Dt polarization and fusion process magnetic confinement inertial confinement

Extraction Valves

Mass Spectrometer

Distillator

Sampler Tanks


Dt polarization and fusion process magnetic confinement inertial confinement

Conclusions

Polarization looks like a MUST for future power plants.

We have in Europe (and in France): ITER to study the magnetic confinement

and MEGAJOULE for the inertial confinement.

The full polarization of DT fuel increases the reactivity by at least 50% and controls

the reaction products direction of emission. Simulations of ICF 100%.

The cost of a polarization station (107 €) is negligible compared to the cost of a reactor (1010 € for ITER).

A first question remain: D and T relaxation times during fusion process ?

We have proposed a “simple” experiment to approach this question, at least for the inertial confinement: POLAF Project accepted at ILE (OSAKA)

Feasibility of the experiment confirmed for D + D → 3He + n reaction

which can also test the RPA features

Polarization of the fuel?

DNP of HD and DT must be revisited seriously somewhere,

as well as high intensity polarized D2 and T2 molecular jets.


Dt polarization and fusion process magnetic confinement inertial confinement

J.-P. Didelez and C. Deutsch, « Persistence of the Polarization in a Fusion Process », LPB 29 (2011) 169


Dt polarization and fusion process magnetic confinement inertial confinement

TNSA on « thick » Targets


Dt polarization and fusion process magnetic confinement inertial confinement

HD Target: NMR Measurements

0.85 T – 1.8 K

Back conversion at room temp.

for 5 hours is 30%


Hd target production

Step I: HD purity monitoring – Quadrupole Mass Spectrometer

HD quality on the market ?

Step II: HD production – Distillation apparatus in Orsay

HD Target: Production

Over 3 month of ageing necessary


Dt polarization and fusion process magnetic confinement inertial confinement

Distillation apparatus in Orsay

Heater

1

To mass spectrometer

3 extraction point

3 temperature probe

Stainless Steel column filled with Stedman Packing:

Heater

2


Dt polarization and fusion process magnetic confinement inertial confinement

Persistence of the Polarization

in a Fusion Process

What to do ?

  • Demontrate the persistence with

  • an ultrashort laser and a polarized HD target

  • (HIIF2010, GSI Darmstadt, August 2010)

  • Develop the Dynamic Nuclear Polarization of HD

  • (SPIN2010, KFA Jülich, September 2010)

  • DNP of DT molecules

  • (HIIF2012, ? )

  • Fusion of polarized DT at Mégajoule

  • (20??)


Dt polarization and fusion process magnetic confinement inertial confinement

Mais que diable font les chercheurs émérites

dans ce laboratoire ?


  • Login