| Miniproposals |
| Operators | |
| Session leader(s): | |
| Physics operator(s): | Greg Wallace |
| Engineering operator(s): | Bill Cochran |
| Engineering Operator Run Comment |
| automatically entered by signon - please replace with real comment |
| Session Leader Plans |
| Entered: Jun 27 2012 02:08:39:090PM |
| Author: Seung Gyou Baek |
| MP 664 Study of spectral broadening of LH waves (1/2 day, 9AM-1PM)
SL: S.G. Baek PO: G. Wallace **Target plasma : 1120612009 Bt = 5.4 T, Ip = 550 kA, nebar = 0.6 ~ 1.4e20 m^-3, LSN Plh= 800 kW, Tlh = 0.7 ~ 1.5 sec, N|| = 75 deg ** Goal : (a) Spectral measurements of LH waves using the multiple probes (b) Spectral measurements of low frequency ion cyclotron modes using the inner wall probes - Agilent spectrum analyzer can be triggered single time within a discharge (c) Measurement of the SOL density / temperature profiles using both the inner wall and A-port scanning probes (d) Measurement of fluctuations using a X-mode reflectometer in front of the LH launcher (e) Measurement of fluctuations using GPI for the part 1 & 2 **** Shot plan 1. LH power scan (nebar ~ 1.3e20 m^-3) to increase the LH power (1) Plh = 500 kW (2) Plh = 800 kW Set Plh to maximum available power 2. Fixed density scan (3) nebar = 1.1e20 m^-3 (4) nebar = 0.9e20 m^-3 (5) nebar = 0.7e20 m^-3 3. LSN to USN change within a discharge (e.g. = 1110106017 : may adjust timing) (6) nebar = 1.3e20 m^-3 (7) nebar = 0.7e20 m^-3 Assuming no significant changes in the LH spectra, use USN for the density control 4. USN to Inner wall limited discharge (e.g. = 1100901017 : may adjust timing ) (8) nebar = 1.3e20 m^-3. (9) nebar = 0.7e20 m^-3 5. Density ramp within a discharge (10) nebar = 0.6 ~ 1.4e20 m^-3 for 0.7 sec < t < 1.5 sec If time permits, repeat step 3 and 4 with nebar = 1.1e20 m^-3 (11) repeat step 3 with nebar = 1.0e20 m^-3 (12) repeat step 4 with nebar = 1.0e20 m^-3 If time permits, try the discharges with different plasma current ( Ip = 800 kA, discharge 1120612007 (5.4 T, 800 kA) ) ** Diagnostic LH probe & Agilent S.A. Thomson HXR ECE Polarimeter MSE/DNB X-mode reflectometer GPI |
| Entered: Jun 28 2012 08:18:17:490AM |
| Author: Ian Faust |
| MP710 Impurity transport in non-inductive plasmas
L. Delgado-Aparicio, N. Howard, I. Faust and M. Chilenski Goal: Observe and diagnose plasmas in which known non-recycling impurities (Calcium) are injected into a tokamak plasma with reduced ware-pinch (increased non-inductive current drive). Observe sawtooth-free impurity transport in the core. Discharge Plan: Due to the high density lower hybrid discharges in the 1/2st half of the day, the second half will inherently utilize the following characteristics: 1) LH launcher is conditioned for full power operation 2) The Alcator C-Mod wall is loaded with Deuterium due to higher density operation Step 1) achieve a locked mode (reference: 1120607004) (max x2 plasmas) Use all 3 segments outlined in that shot. Set integration time to HiReX to 20 ms. Try to reduce density as much as possible, reference shot has locked mode at nl_04 ~8e19. Step 2) Run LH power at 800 kW forward power. (Reference topology 1120601012, using 90 phasing, different density) for 1s starting at .7s. LBO injections at [.9 ,1.1, 1.3,1.5]. Extend flat-top to insure LH pulse is completely in flat top (t=1.7). Ip=400 kA, Bt = 5.4 T. Change HiRex Timing to 2ms. Goal of this plasma is to achieve nl_04 = 4e19, and will probably not be achieved at first attempt. This step provides a pseudo-density scan. Use cryo in USN in order to assist and control density. When parameters requested are achieved, move to step 3. Allocate 3-4 shots for this purpose. (4-6 plasmas total at end of step 2). In the case of MHD in continue plan as laid out, the reduction of power should reduce MHD drive. Step 3) Reduce LH power at 200kW forward power increments while maintaining target plasma set in step 2. LH parameters (pulse length, phasing) stay the same, and same goes for HiReX and LBO. Achieve 2 plasmas per scenario for statistical purposes. This will require 6-8 plasmas (200,400,600 kW). Total shot use: 10-18 plasmas. Step 4) Achieve 'control' discharge. Remove LH power entirely. Use standard phasing on E antenna (transmitter 2, standard phasing) to get 800 kW ICRF during timing laid out for LHCD. Use standard LBO/ HiReX setup as in step 2 guideline. Requires x2 plasmas. Total shot use: 12-20 plasmas. At this point, necessary goals are achieved. In the case that more run time is available: Step 5) Remove ICRF. Rerun step 4). x2 plasmas Diagnostics: Mission Critical- Thomson Scattering, HiRex with Ca crystal. LBO with CaF2 slide. MSE and DNB. XTOMO, polarimeter and HXR. Z effective systems. TCI. Secondary Diagnostics (still required) PCI, Magnetics, Reflectometery for fluctuations, CECE. AXUV diodes. ECE diagnostics. Tertiary Diagnostics: All passive diagnostics that do not require modifications to said run plan. |
| Physics Operators Plans |
| Entered: Jun 27 2012 02:35:57:000PM |
| Author: Greg Wallace |
| -----------------
Engineering Setup ----------------- Run begins at 09:00 and ends at 17:00 MP 664 from 09:00 to 13:00 MP 710 from 13:00 to 17:00 Power systems as on: 1120612009 Acoil: +Dtop -Dbot -Jtop +Jbot (standard) Hybrid Enabled Gas setup: Fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid DISABLED (PG1) leave B-side upper as is Hybrid DISABLED (PG2) fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3) fill NINJA with 10 psi D2 DISABLED Enable gate-valves and shutters: ECE, VUV, HiREX Sr, Xeus/LoWEUS Leave z-bolo shutter as is (should be open) Torvac gatevalve toggle (yes/no): no Boronization(yes/no): no Overnight ECDC (yes/no): yes after LH launcher has been retracted. ICRF(yes/no): no LH(yes/no): yes Cryopump (yes/no): yes DNB (yes/no): yes Vessel temperature: 35/35/35 ------------------------------ ECDC Parameters (if requested) ------------------------------ gas and pressure: D2 at 2e-4 Torr sweep: 44/45/103 cm scan: 20/120 s Shot plan: Start with 1120612009. Bt = 5.4 T, Ip = 550 kA, nebar = 1.3e20 m^-3, LSN LH starting parameters: P = 500 kW net (120 kW/klystron), t = 0.7 ~ 1.5 sec, phasing = 75 deg |
| Session Leader Summaries |
| Entered: Jun 28 2012 10:07:05:400AM |
| Author: Seung Gyou Baek |
| Due to the machine problem (vacuum leak), we had no plasma discharges today. |
| Physics Operator Summaries |
| Entered: Jun 28 2012 10:34:51:893AM |
| Author: Greg Wallace |
| An air leak developed around 8:25am today. The pressure peaked at about 40 Torr. The leak slowed/stopped and the vessel pressure recovered to ~3e-5 Torr. Mass 18 is by far the largest signal on the RGA indicating a large amount of water has accumulated in the vessel. The run was canceled and we will be cleaning up with bake and ECDC for the day today. |
| Session Leader Comments |
| Physics Operator Comments | |||
| Jun 28 2012 10:35:19:827AM | Greg Wallace | Run canceled due to air leak. | |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |