TFE 3/2/2004 – Fuel retention in JET - J. Bucalossi / T. Loarer Assessment of fuel retention in JET : Contingency – 2 shifts on 6 th of february E. Tsitrone for J. Bucalossi and T. Loarer Motivation Previous results Pulse configuration
TFE 3/2/2004 – Fuel retention in JET - J. Bucalossi / T. Loarer Motivation : tritium retention in ITER need for experimental data Code validation : Underestimation of the JET DTE1 T retention by a factor Nb of ITER pulses T inventory (g) ITER predictions : Codeposition dominates T retention : 1 to 4 g of T per 400s pulse ITER in vessel T inventory limit : 360 g of T 100 to 350 pulses G. Federici, Workshop on In Vessel Tritium Inventory, JET, March 2003
TFE 3/2/2004 – Fuel retention in JET - J. Bucalossi / T. Loarer Previous results : H mode long discharges at JET Integrated particle balance : Long term retention : 10 % of injected gas Particle balance during shot : Dynamic retention : 50 % of injected gas ( TS) Medium Gas Puff 16 s of flat top in H mode Ip = 1 MA, 6 MW of NBI Shot 59197
TFE 3/2/2004 – Fuel retention in JET - J. Bucalossi / T. Loarer Assessment of fuel retention in JET TFE C14 - Feb. 6th Early and Late SCs: J. Bucalossi/T. Loarer SLs: G. Matthews/M. Stamp Aim: perform a gas balance with the maximum accuracy Divertor Cryopump regeneration just before and just after the session (+ gas analysis) no NBI (no LHCD) to avoid NBI Box (LHCD) pumping no disruption high D 2 fuelling rate (in feedback control to avoid disruption) maximum pulse rate Calibration : gas injection w/o B field and w/o div cryopump (to calibrate pressure gauges) dry run with gas puff (to check divertor pumping speed) Scenario: 2MA/2.43T, 5-6MW ICRH, 42 MHz dipole, high density (90fr) ref. pulse #61751… (POG/TTE_CLEANUP/1.3), Gas ~ 6 bar.l combined with QMB available data for divertor configuration choice (DOC L/Vertical/Corner/Horizontal target,4 pulse types ?) 40 pulses at 6 bar.l/pulse ~ 240 bar.l (reasonable for PCD and GB)
TFE 3/2/2004 – Fuel retention in JET - J. Bucalossi / T. Loarer Typical scenario (from TTE clean-up) JPN Plasma Parameters x Electrons / s Gas Injection mbar Pressure Measurements P divertor /P vessel Z Xp (m) Ip (MA) ne (10 19 m -3 ) RF (MW) sub-div vessel NBI (MW)
TFE 3/2/2004 – Fuel retention in JET - J. Bucalossi / T. Loarer t (s) JPN Retention Tentative particle balance (with 2001 calibrations) “Dynamic” D retention Feb 6 th in-vessel fuel retention ~ (total gas input – PD Regen.)/total gas input