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format: markdown
title: Session 8 February 2019, all new shots for Daniela Kropáčková
...

#Session goal

Perform a series of shots with the following parameters:

    Bt capacitor voltage: 1300 V
    CD capacitor voltage: 500 V
    t_CD: 0 ms
    Gas pressure: 20 mPa
    Working gas: H
    Preionization: Upper el. gun

Operating probes:

* Tunnel probe: $r = 60, 65, 70, 75, 80, 85, 90$ mm (this refers to the tunnel centre), all four electrode (two tunnels, two back plates) at -100 V (Isat regime)
    * Note: Honza Stöckel's amplifier was used to supply the voltage
    * data acquisition system: Papouch Stockel
    * signal names: *tp_t_limiter*, *tp_bp_limiter*, *tp_t_op_limiter*, *tp_bp_op_limiter*
* Double rake probe: $r = 92$ mm (this refers to the pin deepest in the plasma), all 8 measuring pins (pin 9-16) at -143 V (Isat regime)
    * data acquisition system: Papouch Zacek
    * signal names: *drppin01*-*drppin04*, *drppin09*-*droppin16*
    * Note: throughout the session, pin 13 collects flat zero (probably bad contact somewhere) and pin 11 falls to zero at some point in the discharge (unknown reason)
    * also at random times, Papouch Zacek as a whole either collects flat zero, or doesn't collect anything entirely (Vojtech Svoboda suggests that this is due to poor triggering and thinks that moving the data acquisition system further from the tokamak may reduce the interference in the trigger)
    * first pin position was measured as $r=J-32$ mm, where $J$ is the easiest distance to measure on the manipulator (refer to [the DRP page](/Diagnostics/ParticleFlux/DoubleRakeProbe/index))
    * as [one of Sergei's reports](/TrainingCourses/FTTF/2018-2019/SerKulk/Reports/Report_6.12.18) shows, the probe head is oriented in an awkward direction - now it makes sense why pin 12 measures significantly higher signal than pin 16; pin 16 (and the entire row, which is the one that provides the full profile) is toroidally shadowed by the probe head

[<img src="http://golem.fjfi.cvut.cz/wiki/Experiments/EdgePlasmaPhysics/ParticleFlux/TunnelProbe/Reports/8_Feb_2019_29467_drp.png" width="1000" />](/Experiments/EdgePlasmaPhysics/ParticleFlux/TunnelProbe/Reports/8_Feb_2019_29467_drp.png)

*Example of DRP signal time evolution. The y axis is proportional to $I_{sat}$. Pins 16, 15 and 14 are in the SOL (probe connections shown [in one of Sergei's reports](/TrainingCourses/FTTF/2018-2019/SerKulk/Reports/Report_21.11.18)), the rest are within the port so they measure zero current.*

* Standard diagnostics
* Bolometer array

The goal is to measure Mach number profile at clockwise and anticlockwise field orientation.

#Session discharges

In the morning, the chamber was baked and a hydrogen glow discharge was performed.

**29459**: Master test, vacuum shot

**29450**: Master test, plasma discharge

**29451-29456**: more tests, trying to achieve a reproducible discharge regime (#29455 - Papouch Zacek, housing DRP, collected no data, #29453 and #29454 - Papuch Zacek collected flat zero)

**29457**: $r=90$ mm, CW

**29458**: $r=85$ mm, CW, tunnel probe back plate and tunnel facing away from the limiter collected flat zero

**29459**: $r=85$ mm, CW, tunnel probe worked, Papouch Zacek collected flat zero

**29460**: $r=80$ mm, CW

**29461**: $r=75$ mm, CW, Papouch Zacek collected flat zero

**29462**: $r=70$ mm, CW, tunnel of the probe facing limiter shows two weird negative jumps in the collected current

**29463**: $r=65$ mm, CW, tunnel probe facing away from the limiter collects poorly

**29464**: $r=65$ mm, CW, beautiful shot lasting full 17 ms

**29465**: $r=60$ mm, CW

**29466**: $r=62.5$ mm, CW

**29467**: $r=67.5$ mm, CW

**29468**: $r=72.5$ mm, CW

**29469**: $r=77.5$ mm, CW

**29470**: $r=82.5$ mm, CW, tunnel probe facing away from the limiter collects poorly

**29471**: $r=82.5$ mm, CW

**29472**: $r=87.5$ mm, CW

**29473**: $r=92.5$ mm, CW

**29474**: $r=92.5$ mm, ACW, all probes work (as much as they do, anyway), but their signals are considerably lower - effect of plasma being higher?

**29475**: $r=90$ mm, ACW, the shot is 2 ms longer than the previous shot (maybe effect of the reverse field configuration change)

**29476**: $r=87.5$ mm, ACW

**29477**: $r=85$ mm, ACW

**29478**: $r=80$ mm, ACW

**29479**: $r=75$ mm, ACW

**29480**: $r=70$ mm, ACW

**29481**" $r=65$ mm, ACW

**29482**, $r=60$ mm, ACW, tunnel probe facing away from the limiter collects poorly, $U_{loop}$ has a bump at the beginning

**29483**: $r=60$ mm, ACW (this is the last shot for Daniela's purposes, now the DRP is moved inside and the tunnel probe will be swept between approx -100 V and 20 V)

**29484**: $r_{TP}=70$ mm, $r_{DRP}=84$ mm, CW, only about 5 mPa instead of 8 mPa

**29485**: $r_{TP}=70$ mm, $r_{DRP}=84$ mm, CW, $p_H=6$ mPa

**29486**: $r_{TP}=70$ mm, $r_{DRP}=73$ mm, CW, 19 ms shot, $p_H=5$ mPa, 

**29487**: $r_{TP}=70$ mm, $r_{DRP}=73$ mm, CW, half the DRP pins collected no data

**29488**: $r_{TP}=70$ mm, $r_{DRP}=61$ mm, CW, slightly shorter discharge (DRP is pretty deep inside...)

**29489**: $r_{TP}=70$ mm, $r_{DRP}=61$ mm, ACW

**29490**: $r_{TP}=70$ mm, $r_{DRP}=69$ mm, ACW

**29491**: $r_{DRP}=82$ mm, ACW, tunnel probe turned off