The assembly consists of two tantalum foils, 0.001" thick, which are radially crimped to form a cylindrical surface. The outside support are two P2N conditioning legs, and the inside supports are tantalum tapered rings. The solidworks geometry for this test is ITD0811 in PDM.
A first current ramp up to 600 amperes on the bare naked target is attempted to benchmark the current/voltage increase in a bare target, so that we have reference values for future rampings with graphite and target material inside.
Wednesday, January 22, 2020, 18:07
A P2N container with no heat shields, and no graphite container was installed in the EVAP1
Chamber is currently being evacuated.
Thursday, January 23, 2020, 09:45
Pressure IGP1=1.87e-6 Torr
Final desired current TGHT = 600 A
Manually tapped to 40 A
The voltage looks ok, at 32 A the voltage's behavior change (see picture "voltage at 32 A") but is stable
Thursday, January 23, 2020, 13:20
Autoramp is set to 4/30s to 300 A
The voltage and vacuum were stable so the autoramp was kept at 4/30s and the final current was set to 600 A
At 600 A the voltage was 2.4 V, the current and voltage remained stable for 1 hour (see figures 600A and 600A-zoomed)
Thursday, January 23, 2020, 15:57
The current was ramp down to 0 A at -5A/20s
Thursday, January 23, 2020, 16:36
After 10 min at 0A, the current was ramp up to 600 A at 4A/30s.
At 600 A the voltage was 2.43 V (TGHT)
The container was left at 600 A overnight.
Friday, January 24, 2020, 10:51
The PN2 stayed at 600 A for 15 hrs
The voltage increased 0.1 V during the first 7hr at 600 A and then it stabilized at 2.5 V (see figure "second ramp voltage")
Friday, January 24, 2020, 10:57
The current was ramp down to 0A at -5A/20s
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