Discussion on TC-2 JEXDiscussion on TC-2 JEX

Culham, 25.3.2010Culham, 25.3.2010

Yves Martin, Andreas Pitzschke

Centre de Recherches en Physique des Plasmas

Association Euratom - Confédération Suisse

Ecole Polytechnique Fédérale de Lausanne (EPFL)

CH - 1015 Lausanne, Switzerland

OutlineOutline

Preamble• TCV: H-modes with ECH-X3

Discussion on TC-2• Goals• Future work

Yves Martin, TC-2 JEX, ITPA T&C Meeting, Culham, 22-25.3.2010 2

TCV – characteristicsTCV – characteristics

• High flexibility in plasma shaping 16 shaping coils, independently driven

• High power, high flexibility ECH system 3MW X2 (lateral) + 1.5MW X3 (top), steerable mirrors

Yves Martin, TC-2 JEX, ITPA T&C Meeting, Culham, 22-25.3.2010 3

TCV – H-mode operational domainTCV – H-mode operational domain

• Ohmic Diverted configuration, some shaping (, , Xpt location)

Ip>250kA, ne>3.5 1019m-3

• ECH – X3 Better absorption when already in H-mode

Yves Martin, TC-2 JEX, ITPA T&C Meeting, Culham, 22-25.3.2010 4

TCV – some examplesTCV – some examples

Yves Martin, TC-2 JEX, ITPA T&C Meeting, Culham, 22-25.3.2010 5

Ip ~ 400kAne ~ 4.5 1019m-3

~1.7 ~ 0.6

Unfavourable

Favourable

Favourable

Favourable

TCV – 2 other examplesTCV – 2 other examples

Yves Martin, TC-2 JEX, ITPA T&C Meeting, Culham, 22-25.3.2010 6

Y.Martin et al., PPCF 48 (2006), A163

L.Porte et al., NF 47 (2007), 952

TCV – In the H factor vs PTCV – In the H factor vs PLL/P/Pthreshthresh mapmap

Yves Martin, TC-2 JEX, ITPA T&C Meeting, Culham, 22-25.3.2010 7

Ohmic

1 point

1 discharge

TCV – Future workTCV – Future work

Ohmic• Wide ranges in plasma parameters• Far from H~1• => indications of dependences

ECH – X3• Closer to H~1 but far from PL/Pthresh~1

• Smaller diversity in plasma shapes, conditions

=> Exploration of TCV database=> New experiments with low power X3

Yves Martin, TC-2 JEX, ITPA T&C Meeting, Culham, 22-25.3.2010 8

Discussion TC-2Discussion TC-2

Goals of TC-21. Test ITER scenario (initial goal)

L-H transition at low density (0.4ngr) with P~Pthresh

Reach a target density of 0.8ngr (naturally + ev. gas puff) without increasing power

Characterise confinement (H factor, ELMs, ...) Increase power either before L-H transition or

during density ramp to reach H~1

2. Explore existing devices databases (decided last meet.) Identify stationary phases with PL/Pthresh~1 and

H~1 Characterise the plasma conditions

Yves Martin, TC-2 JEX, ITPA T&C Meeting, Culham, 22-25.3.2010 9

Discussion TC-2Discussion TC-2

Future work• Pursue investigation / experiment

Complete DB investigation for each individual devices

Compare/discuss identified trends (next meeting?) Identify common trends (next meeting?) Perform planned experiment exploiting common trends

• Other ideas ?

• Commitment Teams / devices ? Names ? Delays ?

Yves Martin, TC-2 JEX, ITPA T&C Meeting, Culham, 22-25.3.2010 10