Associazione Euratom-ENEA sulla Fusione ----- Culham 15-17 September 2003 RISERVA Verticale

Associazione Euratom-ENEA sulla Fusione -----

Culham 15-17 September 2003

RISERVAVerticale



The idea is to form an ULART by producing a Screw Pinch that will be destabilized by

increasing the longitudinal arc current Ie: such a configuration has been obtained for the first

time on the TS-3 experiment (Tokyo University)

Screw Pinch with longitudinal field BZ toroidal field Bsafety factor qPinch = 2 Pinch BZ/LPinch B

Aims of PROTO-SPHERA



ProtosPhera CATIA Drawing



Pyrex vacuum vessel MicroWave

Interferometry

Visible Spectroscopy

Cathode

8 conductors for the Ie return

External coils.

Gas Feed

Vacuum Pump

Vacuum Pump

PROTO-PINCH Experimental Set-Up



COILSTwo groups of PF coils (jPF≤2 kA/cm2), each composed

by coils connected in series

Group 'B' - shape the pinch with constant currents

Group 'A' - compress the ST with variable currents



ST diameter 2•Rsph=0.7m

Toroidal plasma current Ip=240kA

Aspect ratio A=1.2, elongation =2.35

Similar to the START spherical torus experiment

Pinch current Ie=60 kA « Itf≈200 kA (START centerpost)

Main Features



Cost, Schedule & Size

Vessel, including: tiles, supports,Baking system and base 665,000 €Design contract 77,000 € Subtotal 742,000 €

Poloidal field coils, including :feedthroughs and cooling system 826,000 € Design contract 77,000 €Subtotal 903,000 €

Anode and Cathode, includingfeedthroughs and cooling system 297,000 € Design contract 50,000 € Subtotal 347,000 €

Assembly contract 90,000 €

Pumps, gas feed & control system 200,000 €

TOTAL 2,282,000 €

Power supply:Pinch feeder ‘P’ 904,000 €Cathode feeder ‘K’ 102,000 €PF feeder ‘A’ 150,000 €PF feeder ‘B’ 31,000 €Subtotal 1,187,000 €Electrical work contract 93,000 €TOTAL Power Supply 1,280,000 €GRAND TOTAL 3,562,000 €



MultiPinch Costs

•Capital costs of multi-pinch testLoad assembly (vessel and electrodes) : 460000 €PF coils and sustaining columns : 230000 € Power supplies : 246000 € TOTAL : 936000 €

•If, after the multi-pinch test, the decision to build PROTO-SPHERA was taken, between 585000 € and 770000 € of the capital expenditure of the multi-pinch test could be still put at work.

Schedule of multi-pinch test •If proposal is accepted in 2003:

first plasma by the end of 2005.



Panel Question & Answers1. Is the physics basis for undertaking an experiment as

proposed with PROTO-SPHERA adequate? OK, BUT We recommend that a wider range of operation scenarios of and pressure profiles be analyzed ...

2) Are the PROTO-PINCH electrode experiments a sufficient technical basis for a reliable electrode operation in PROTO-SPHERA?

OK, BUT… are not yet adequate for reliable multi-electrode operation...

3) … In particular, is the proposed size adequate for the purposes of a Concept Exploration Experiment? .. OK

4) How likely is .... to advance the present state of science and technology substantially.. OK

5) .. likely to produce new information that is adequate as basis to extrapolate to a SPHERA device that achieves fusion relevant paramenters? OK

6) What diagnostics should be planned in order to properly measure the properties of the PROTO-SPHERA plasma? OK

7) What are the unique contributions of the proposed experiment to the world magnetic fusion programs, and in particular to the European Magnetic Fusion Program during the VIth FP? OK

Documents

Associazione Euratom-ENEA sulla Fusione ----- Culham 15-17 September 2003 RISERVA Verticale