Logbook from 24 February 2002 to 28 June 2002

sun 24-Feb-2002

• No shot.
• Start of the preparation of the diagnostic for the next experiments.
• Changed the inner cables with new ones bought from Padova. These are 12 double shielding (or triaxial) teflon cables. The diodes used are:

  diode anode (socket pin) 1 12 3 12 5 12 7 12 9 12 11 12	this set of cables have both the shielding connected to the common anode (pin 12 on the teflon socket). The inner shieldings are connected together and go to pin 12 with a brown cable; the outer ones are connected together and go to pin 12 with a green cable.
  diode anode (socket pin) 10 1 12 1 13 1 15 1 17 1 19 1	this set of cables have only the inner shielding connected to the common anode (pin 1 on the teflon socket); they are connected together and go to pin 1 with a brown cable; the outer ones are floating.

  
  All these cables have the two shieldings connected together on the flange side (lemo connector). The cables are inside an isolated copper shielding.
• Light tightness ok.
• Distance of the array of detectors from the edge of the opened probe=8.40mm (before was 8.15mm). A new geometry file must be used (this is automatically done by the IDL routine that reads the values of the impact parameters, angles etc.)

mon 25-Feb-2002

• Diagnostic connected to MST, VAT closed. New cables from the flange to the amplifiers are used; again, they are double shielding. The old layout of amplifiers is used (3 Femto and 9 HSX).
• Two new signals are measured, those of diode 10 and 12; they are associated with cables 20 and 21, resp., and goes to the input 5 and 6 of the Joerger on slot 15 (RFX_612_2). The new signals are \SXR_EXTR_10 and \SXR_EXTR_11.
• Shot from 1020225001 to 149. Plasma current up to 300kA; SXR signals present only starting from shot 142, and low; a few signals have an oscillating baseline.
• The amplifier gains have been changed. From shot 142 to 149:

  diode	1	3	5	7	9	10	11	12	13	15	17	19
  cable	10	11	12	13	14	20	15	21	16	17	18	19
  logical	0	1	2	3	4	10	5	11	6	7	8	9
  gain 10^	8	8	7	8	8	7	8	7	8	8	7	8

tue 26-Feb-2002

• Leak test: the feedthrough of the diode 3 and 17 on the flange have been replaced (17 is the second time...). Now the vacuum is ok.
• Replaced the Be filter with the 12.5 micron, 16 micron real (the same used during the first week of november 2001).
• Installed in the metal box the new 9 Femto together with the 3 presently used. Now all the signals are measured by 12 all equal amplifiers. The cables from the flange to the box are inside a thick copper shielding. All these box, copper shielding etc are connected to MST.
• No shot.

wed 27-Feb-2002

• The electronic layout is now:

  diode	Femto	Cable	Sign	Gain (10^)	Logical
  1	1	10	-1	8	0
  3	2	11	-1	8	1
  5	3	12	-1	8	2
  7	4	13	-1	8	3
  9	5	14	-1	8	4
  10	11	20	-1	8	10
  11	6	15	-1	8	5
  12	12	21	-1	8	11
  13	7	16	-1	8	6
  15	8	17	-1	8	7
  17	9	18	-1	8	8
  19	10	19	-1	8	9

  and all the amplifiers are now at 10^8; the other settings for the ampli are: Low Noise, FBW, GND, DC.
• Created the new pulse-file in \MST_MISC but it is not yet available on-line.
• Shot from 1020227001 to 043. These are shots to test the new cables and the new electronic layout.
  • 027 - first shot with plasma; probe extracted, VAT closed;
  • 031 - VAT open, probe in its measuring position; SXR electric circuit grounded on the Camac side;
  • 034 - diode 9,10,11,12,13 gain=10^7;
  • 038 - probe turned 180 degrees (poloidally) to check if the diode 1 has a noisy signals due to its position or to its cables;
• At the end (after last shot=043) also diode 7 has gain=10^7, and the probe has been turned to its usual poloidal position. The final configuration is:

  diode	Femto	Cable	Sign	Gain (10^)	Logical
  1	1	10	-1	8	0
  3	2	11	-1	8	1
  5	3	12	-1	8	2
  7	4	13	-1	7	3
  9	5	14	-1	7	4
  10	11	20	-1	7	10
  11	6	15	-1	7	5
  12	12	21	-1	7	11
  13	7	16	-1	7	6
  15	8	17	-1	8	7
  17	9	18	-1	8	8
  19	10	19	-1	8	9

• Apparently, no major changes are found on the level of noise of the signals, despite the use of the triaxial cables, copper shielding etc.
• This noise, most of all pick-up noise between 0 and 5 ms (beginning of the discharge) is mainly composed by high frequency (>200kHz) components.

thu 28-Feb-2002

• Shot from 1020228001 to 113. These are PPCD shots, current=400kA (capacitor banks C1,C2), ne=1x10^15 cm-3, and it's the first day of the campaign dedicated to the SXR probe and fast magnetic measurements.
• SXR electric circuit grounded on MST (using a cable from one of the Lemo to one of the bolt on the flange). Femto: GND, Low Noise, FBW, DC.
  • 001-018 - sustained shots @ 400kA;
  • 006 - diode 15=10^7; now the power supply of the Femto amplifiers is ground isolated (this seems to reduce the noise);
  • 019-113 - PPCD @ 400kA;
  • 022 - diode 1,3=10^8, diode 5,17,19=10^7, 7,9,10,11,12,13,15=10^6; this is the configuration to use with PPCD shots:

    diode	Femto	Cable	Sign	Gain (10^)	Logical
    1	1	10	-1	8	0
    3	2	11	-1	8	1
    5	3	12	-1	7	2
    7	4	13	-1	6	3
    9	5	14	-1	6	4
    10	11	20	-1	6	10
    11	6	15	-1	6	5
    12	12	21	-1	6	11
    13	7	16	-1	6	6
    15	8	17	-1	6	7
    17	9	18	-1	7	8
    19	10	19	-1	7	9

  • 082 - good example of QSH (m=1, n=6) with a rotating structure; note the double oscillation in diode 11 and 12 between 16 and 17 ms;
  • 102-108 - diode 10 and 12=10^6 but with High Bandwidth (using the multiplier x100).

fri 1-Mar-2002

• Shot from 1020301001 to 133. Ephi reversal discharges (capacitor banks C1,C2), 400kA, ne=1x10^15 cm-3.
• The gains for today are:

  diode	Femto	Cable	Sign	Gain (10^)	Logical
  1	1	10	-1	8	0
  3	2	11	-1	8	1
  5	3	12	-1	8	2
  7	4	13	-1	7	3
  9	5	14	-1	7	4
  10	11	20	-1	7	10
  11	6	15	-1	7	5
  12	12	21	-1	7	11
  13	7	16	-1	7	6
  15	8	17	-1	7	7
  17	9	18	-1	8	8
  19	10	19	-1	8	9

  with the only exception of shot 23 and 24, where diode 15=10^8; it saturates, so the previous table is the best configuration for this kind of shot.
• The only observation is that the 12 Femto inside the box are sligthly hot, so we left the box open in the night.

sat 2-Mar-2002

• Shot from 1020302001 to 144. Sustained discharges, sawteeth (capacitor banks C1,C2,C3 and C4), 400kA, ne=0.8-1x10^15 cm-3.
• The gains are the same of yesterday.

sun 3-Mar-2002

• No shot.

mon 4-Mar-2002

• Shot from 1020304001 to 119. These are PPCD shots, current=400kA (capacitor banks C1,C2), ne=1x10^15 cm-3.
• The gains are the same of 28 february.
• Shot 69-92: diode 10 is measured with the prototype of the ELAD amplifier; gain=10^6, with all the dip swith OFF. The signals are good, there is a little offset and maybe the gain are not calibrated (they are not exactly 1.0e6 but something greater than 1).
• Shot 93-94: diode 10 back to Femto, now the ELAD is on diode 19; gain=10^7, dip switch 1=off, 2=on, 3=off, 4=off. No signal is present.
• Shot 95-100: dip switch ELAD changed, gain=10^7 but using another amplifier stage; 1=on, 2=off, 3=off, 4=off. Now the signal is present.
• Shot 101-105: diode 19 on a HSX amplifier, gain=10^7; comparing similar shots, the ratio diode17/diode19 change using this HSX ampli with respect to the Femto, indicating that also the HSX amplifiers have not calibrated gains.
• After shot 105 the diagnostic has been disconnected and the Be filter removed, to check the probe as a bolometer; it took 45 minutes, in two persons, to perform this operation.
• Shot 106-113: probe connected to MST but extracted and VAT closed; all Femto are used, gain=10^4 for all diodes.
• Shot 114 and 115: VAT open but probe extracted; only diode 9,10,11 and 12 have a current.
• Shot 116-119: probe in its measuring position. The cable 19 (diode 19) has been disconnected from the output of its Femto amplifier, terminated with 50 ohm and left close to the metal box: there is a little offset, but the initial pick-up noise, between 0 and 5 ms, is still present. This is an indication that part of the noise comes after the amplifiers.
• A few bolometers saturate, but with a value of + or -30 V (actually is the ADC that saturates); there is also a different noise, that goes to -30 V.

tue 5-Mar-2002

• Shot from 1020305001 to 146. Ephi reversal discharges (capacitor banks C1,C2), 400kA, ne=1x10^15 cm-3.
• The probe is actually used as a bolometer.
• The gains for today are all 10^4.
• From shot 47 to 64 there are PPCD shot.
• From shot 53 to 64 all gain are 10^5.
• After shot 64 the diagnstic has been disconnected from MST to replace the IRD array of diodes with three single diodes Eurysis; they have different area but they are numbered 1,10 and 19, just like the two extreme and the central chord in the IRD array. The measured signals, during these shots, show that the pick-up is still present on all channels. Installed also the 12.5 micron, measured 16, Be filter.
• Shot 116-128: diagnostic connected to MST, VAT closed, Femto all to 10^5; we forgot to connect the ground, so the circuit is floating; pick-up still present, almost the same level. This indicates that the source of this noise is NOT the IRD strip (array of diodes with a common anode).
• Shot 129-134: as before, but the circuit is grounded on the Camac side; pick-up between 0 and 5 ms.
• Shot 135 and 136: probe inserted, VAT open; we use the BNC on the metal panel on the Camac, so again the ground is on the Camac.
• Shot 137-139: diode 1,19=10^7, diode 10=10^6. Despite the increase of 10 and 100 of the gain, the noise has increased less than 10 times; source=after the amplifiers.
• Shot 140 and 141: ground on MST; the isolated BNC are used; diode 10 is not measured.
• Shot 142-146: diode 10 is measured again; the output cables (those that go to the camac) of the 500 and 725 micron SXR diodes have been disconnected from their amplifiers and have been hanged near the metal box (no termination). This is to test the idea that the noise is due to the distance of our amplifiers (and thus of the cables) from the MST vessel, while the three SXR thick filters are close or laying on the vessel. The results are a little bit confusing: 500 micron has a constant signal, drifting from shot to shot to 10V, the 725 micron has a noisy signal, different than 0 at the beginning and decreasing to 0 after 10 ms. This should be the Joerger behaviour (?). It is not clear why, with a similar test, we see the pick-up at the beginning of the discharge.

wed 6-Mar-2002

• No shot.
• The IRD array is again on the probe.
• The diode 1 is not anymore used; insted, diode 20 is used (to get more resolution on the LFS edge of the plasma).
• A few examples of the last week experiments have been reported on the meeting this morning.

thu 7-Mar-2002

• No shot.
• Discussion with the MST people about the last results and the installation of the new probe; discussion with J.Sarff about the noise on the signals and definition of a number of tests.
• The new probe will be installed on the same toroidal location, in the 165 degrees poloidal porthole; to get the two fans of lines of sight (that of the existing one and the new one) perpendicular the extractable probe will be moved to the 75 degrees porthole.
• MST people is interested on the new ELAD amplifiers; there is also the proposal to use the two probes as bolometers.

fri 8-Mar-2002

• No shot.
• Get back to Italy.

sat 9-Mar-2002

• Shot from 1020309001 to 100.

sun 10-Mar-2002

• Shot form 1020310001 to 011.

mon 11-Mar-2002

• No shot.

tue 12-Mar-2002

• Shot from 1020312001 to 076.
• The power supply is now moved to the digitizer crate and grounded there. All the output cables are using metal panel BNC connectors on the digitizer crate. Probe housing is connected to MST and is extracted. The crate ground goes also to the box housing the amplifier, the PS neutral (zero volt terminal on the ps distribution terminal in the box), and the probe housing. The femto outputs are grounded on the digitizer side.
• There seems reduction on noises. The noises before and after discharge are 250 kHz oscillations; the same 'kind' of noise is present on all the SXR measurements of MST (our probe, Be1 and Be2, and the three SXR thick filters).
• Two more Lemo feedthroughs have been found leaky and have been replaced.
• New gains are:

  diode	Femto	Cable	Sign	Gain (10^)	Logical
  20	1	10	-1	8	0
  3	2	11	-1	8	1
  5	3	12	-1	7	2
  7	4	13	-1	7	3
  9	5	14	-1	7	4
  10	11	20	-1	7	10
  11	6	15	-1	7	5
  12	12	21	-1	7	11
  13	7	16	-1	7	6
  15	8	17	-1	7	7
  17	9	18	-1	8	8
  19	10	19	-1	8	9

wed 13-Mar-2002

• Shot from 1020313001 to 010, all without plasma.

thu 14-Mar-2002

• Shot from 1020314001 to 145, Ip=200-250kA.
• ES probe @ low current.

fri 15-Mar-2002

• Shot from 1020315001 to 124; Ip=200-400kA.
• ES probe @ low current.

sat 16-Mar-2002

• Shot from 1020316001 to 156; Ip=200kA, some shots have F>0.
• ES probe @ low current.

sun 17-Mar-2002

• Shot from 1020317001 to 100; Ip=200-400kA.
• 450 kA conditioning.

mon 18-Mar-2002

• No shot.
• OFCD - with feedback.

tue 19-Mar-2002

• Shot from 1020319001 to 121, Ip=400kA. Here we realise of a possible problem on the SXR signals, maybe light tightness.
• Shots 001-022 outputs for diodes 3,5,7,9 are disconnected from Femto amplifiers. From shot 023 to april 4th only output cable for diode 11 is connected to Femto, and the other outputs are disconnected from Femtos.
• CHERS @ high current.

wed 20-Mar-2002

• Shot from 1020320001 to 003, Ip=300kA. SXR data noisy; from this date only diode 11 is measured.
• Maintenance.

thu 21-Mar-2002

• Shot from 1020321001 to 081, Ip=400kA; PPCD from 014 to 044, and in these discharges the SXR signals (actually only diode 11) are saturated.
• CHERS.

fri 22-Mar-2002

• Shot from 1020322001 to 017, Ip=200-300kA.
• Langmuir probe.

sat 23-Mar-2002

• Shot from 1020323001 to 090, Ip=200-400kA; a few shots have F>0.
• Langmuir probe.

sun 24-Mar-2002

• No shot.

mon 25-Mar-2002

• Shot from 1020325001 to 099, Ip=200-400kA, sustained.
• CHERS.

tue 26-Mar-2002

• Shot from 1020326001 to 059.
• Pellet test without plasma.

wed 27-Mar-2002

• Shot from 1020327001 to 003, Ip=300kA.
• Maintenance.

thu 28-Mar-2002

• Shot from 1020328001 to 077, Ip<=250kA. Low SXR signals.
• 1.8 mm pellet injection.

fri 29-Mar-2002

• Shot from 1020329001 to 205, Ip=200-250kA.
• Langmuir probe.

sat 30-Mar-2002

• Shot from 1020330001 to 167, Ip=200-250kA.
• Langmuir probe.

sun 31-Mar-2002

• No shot.

mon 1-Apr-2002

• Shot from 1020401001 to 044, Ip=250kA.
• OFCD.

tue 2-Apr-2002

• Shot from 1020402001 to 123, Ip=200-400kA; PPCD from 73 to 120.
• Chers signal tests.

wed 3-Apr-2002

• Shot from 1020403001 to 003, Ip=200kA.
• Maintenance.

thu 4-Apr-2002

• Shot from 1020404001 to 004, all without plasma.
• OFCD work.

fri 5-Apr-2002

• Shot from 1020405001 to 092, Ip=200-250kA.
• Langmuir am/OFCD pm.
• Shot 001-077, all disconnected cables are terminated with 50 ohm and the signal of the 250 um single diode is connected to Femto #4 (cable 13, diode 7).
• From shot 78 to 92 the probe is extracted and the VAT open.

sat 6-Apr-2002

• Shot from 1020406001 to 090, Ip=200-250kA.
• Langmuir probe.
• Probe is completely extracted, VAT open.

sun 7-Apr-2002

• Shot from 1020407001 to 089, Ip=200-250kA.
• Langmuir probe.
• Probe is completely extracted, VAT open.

mon 8-Apr-2002

• Shot from 1020408001 to 032, Ip=400kA; PPCD from 29 to 32.
• Pellet injection.
• Probe is completely extracted, VAT open.

tue 9-Apr-2002

• Shot from 1020409001 to 074, Ip=200-400kA. All diodes disconnected, except 11 and 13.
• From now on the probe is extracted and the VAT is closed.
• Si(Li) x-ray spectroscopy.
• Shot 001-028, probe is completely extracted, VAT open. From shot 29 the probe has been extracted and the VAT closed. 250 um single diode was disconnected from femto #4 some time in between.

wed 10-Apr-2002

• Shot from 1020410001 to 026, Ip=350kA in the first shots, then no plasma.
• Maintenance; up-to-N2 for TS gate valve.
• Probe completely extracted, VAT closed.

thu 11-Apr-2002

• Shot from 1020411001 to 079, Ip=300-400kA; PPCD from 10 to 66.
• Chers view optimization.
• Probe completely extracted, VAT closed.

fri 12-Apr-2002

• Shot from 1020412001 to 183, Ip=150-250kA.
• Langmuir probe.
• Probe completely extracted, VAT closed.

sat 13-Apr-2002

• Shot from 1020413001 to 127, Ip=200-250kA.
• Langmuir probe.
• Probe completely extracted, VAT closed.

sun 14-Apr-2002

• No shot.
• Probe completely extracted, VAT closed.

mon 15-Apr-2002

• Shot from 1020415001 to 085, Ip=200-400kA. Shots 25-36 and 83-85 are without plasma; 69-82 are PPCD and 72-82 are PPCD+pellet.
• Pellet with improved trigger.
• No SXR signals. Probe completely extracted, VAT closed.

tue 16-Apr-2002

• No shot.
• OFCD tests.

wed 17-Apr-2002

• Shot from 1020417001 to 059, all without plasma.
• Maintenance.
• The probe was taken out and holes have been found on the Be filter. So it was a light tightness problem (we realised on 19 march). There seems arcing spots on the filter which caused damage. We are thinking that grounding the diode on the CAMAC side may have encouraged arcing because the light pollution happened about 10 days after changing grounding.
• Replaced the filter with a new 12.5 um, measured 18 um, and reinstalled the probe on the machine.
• Bill moved the amplifier box.

thu 18-Apr-2002

• Shot from 1020418001 to 181, Ip=200kA.
• Only diode 13 of the SXR probe have the usual pick-up noise at the beginning of the discharge, the other have bit noise.
• Thomson setup.

fri 19-Apr-2002

• Shot from 1020419001 to 125, a lot of shots have no plasma, the other are at Ip=200kA.
• Only diode 13 of the SXR probe have the usual pick-up noise at the beginning of the discharge, the other have bit noise.
• EBW injection.

sat 20-Apr-2002

• Shot from 1020420001 to 137, Ip=200kA; lots of discharges with no plasma; a few are PPCD.
• Only diode 13 of the SXR probe have the usual pick-up noise at the beginning of the discharge, the other have bit noise.
• EBW injection.

sun 21-Apr-2002

• Shot from 1020421001 to 109, Ip=200kA, but most of the shots have no plasma.

mon 22-Apr-2002

• No shot.
• Vent for Thomson flange/OFCD hardware.

tue 23-Apr-2002

• No shot.
• OFCD hardware.

wed 24-Apr-2002

• Shot from 1020424001 to 007, Ip=200kA.
• Maintenance.

thu 25-Apr-2002

• Shot from 1020425001 to 125, Ip=300kA.
• Thomson alignment.

fri 26-Apr-2002

• Shot from 1020426001 to 177, Ip=300kA.
• VAT open, SXR probe extracted; first measurements with the new filter. The signals have not the usual pick-up noise at the beginning of the discharge.
• The probe was extracted, VAT open and grounded on CAMAC.
• Thomson alignment.

sat 27-Apr-2002

• Shot from 1020427001 to 108, most of the discharges are without plasma, at the end some at Ip=200kA.
• NB profile measurements.

sun 28-Apr-2002

• Shot from 1020428001 to 128, Ip=300kA.
• VAT open, SXR_EXTR extracted.

mon 29-Apr-2002

• Shot from 1020429001 to 118, Ip=400kA, C1+C2 capacitor banks.
• SXR noise troubleshooting tests (part 1).

tue 30-Apr-2002

• Shot from 1020430001 to 116, Ip=400kA, C1+C2 capacitor banks.
• SXR noise troubleshooting tests (part 2).
• The main result of these two days of tests is that using iso amplifiers after the amplifiers to 'separate' the ground of the circuit before and after the amplifiers can help reducing (even cancelling) the noise on the signals.

wed 1-May-2002

• No shot.
• Maintenance.

thu 2-May-2002

• No shot.
• OFCD oscillator.

fri 3-May-2002

• Shot from 1020503001 to 046, Ip=300-400kA.
• Only SXR_EXTR diodes 11,12 and 13 measured; from shot 028 only diode 11 and 13.
• Pellet injector trig noise mitigation.

sat 4-May-2002

• No shot.

sun 5-May-2002

• No shot.

mon 6-May-2002

• Shot from 1020506001 to 204, Ip=300kA.
• Diode 11 and 13 of the SXR_EXTR probe connected.
• Thomson alignment.

tue 7-May-2002

• Shot from 1020507001 to 106, Ip=300kA; most are without plasma.
• Diode 11 and 13 of the SXR_EXTR probe connected.
• Ti,Te in 200kA PPCD.

wed 8-May-2002

• Shot from 1020508001 to 004, Ip=200kA.
• All diode connected (with iso-ampli after the Femto) except diodes 10, 17 and 20.
• Maintenance.

thu 9-May-2002 through mon 3-Jun-2002

• Lots of work performed on the two SXR probes; SXR1 probe moved from 90 to 75 degree poloidally; SXR2 (fixed version of the diagnostic) installed during the vent of monday may 20th. Electronic tests with iso amplifiers.

tue 4-Jun-2002

• SXR2 added to the MST pulse-file.

wed 5-Jun-2002 through tue 18-Jun-2002

• First measurements with the two SXR probes. SXR1 with 12 Femto (as before) and SXR2 with the amplifiers borrowed from HSX.

wed 19-Jun-2002

• 12+12 amplifiers used for the two SXR probes. Connected the 12+12 iso amplifiers to the diagnostic (between the output of the amplifier and the cable to the digitizers). These modules have been built by the electronic workshop of MST.

thu 20-Jun-2002 through mon 24-Jun-2002

• No particular work on the SXR diagnostics.

tue 25-Jun-2002

• Run day dedicated to the configuration of the SXR probes.

wed 26-Jun-2002 through fri 28-Jun-2002

• Preparation of the SXR probes for the coming measurements.
• The logbook continues here.

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