We want the elog process to run in verbose mode so that we can see what's going. The idea is to track the events that trigger the elog crashes.

Following an entry on the Elog Help Forum, I added this line to the elog starting script start-elog-nodus:

./elogd -p 8080 -c /cvs/cds/caltech/elog/elog-2.7.5/elogd.cfg -D -v > elogd.log 2>&1

which replaces the old one without the part with the -v argument.

The -v argument should make the verbose output to be written into a file called elogd.log in the same directory as the elog's on Nodus.

I haven't restarted the elog yet because someone might be using it. I'm planning to do it later on today.

So be aware that:

We'll be restarting the elog today at 6.00pm PT. During this time the elog might not be accessible for a few minutes.

 I tried applying the changes but they didn't work. It seems that nodus doesn't like the command syntax.

I have to go through the problem...

The elog is up again.

in order to get the baja4700 cpu  work the jumpers have to be like this

the description of the jumpers can be found here:

we set up a second, independent DAQ system for the analyzer cavity. It has one 16bit D/A card, 16bit A/D card and 12bit A/D card. The system is called "acav1" and has the ip-address 10.0.0.3, which we can access from the ATF as well via fb1 (fb1 is in peters network too). Here is a boot screen dump of the new system with a list of the new channels at the end. The new channels are now in C3, the new numbering scheme for the PSL subsystem, not in C anymore! (but all the old channels are still C as i would take to long to change all the existing medm screens...

                            VxWorks System Boot


Copyright 1984-1996  Wind River Systems, Inc.





CPU: Heurikon Baja4700
Version: 5.3.1
BSP version: 1.1/1
Creation date: Dec 11 1998, 10:29:37




Press any key to stop auto-boot...
 0
auto-booting...


boot device          : ei
processor number     : 0
host name            : bdl1
file name            : /usr1/epics/baja/vxWorks
inet on ethernet (e) : 10.0.0.3:ffffff00
host inet (h)        : 10.0.0.1
user (u)             : root
flags (f)            : 0x0
target name (tn)     : acav1
startup script (s)   : /usr1/epics/acav/startup.cmd

Mapping RAM base to A32 space at 0x40000000... done.
No longer waiting for sysFail to clear. D.Barker 14th Sept 1998
Attaching network interface ei0... done.
Attaching network interface lo0... done.
Loading... 795028
Starting at 0x80010000...

Mapping RAM base to A32 space at 0x40000000... done.
No longer waiting for sysFail to clear. D.Barker 14th Sept 1998
Attaching network interface ei0... done.
Attaching network interface lo0... done.
Mounting NFS file systems from host bdl1 for target acav1:
...done
Loading symbol table from bdl1:/usr1/epics/baja/vxWorks.sym ...done


 ]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]
 ]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]
 ]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]
      ]]]]]]]]]]]  ]]]]     ]]]]]]]]]]       ]]              ]]]]         (R)
 ]     ]]]]]]]]]  ]]]]]]     ]]]]]]]]       ]]               ]]]]
 ]]     ]]]]]]]  ]]]]]]]]     ]]]]]] ]     ]]                ]]]]
 ]]]     ]]]]] ]    ]]]  ]     ]]]] ]]]   ]]]]]]]]]  ]]]] ]] ]]]]  ]]   ]]]]]
 ]]]]     ]]]  ]]    ]  ]]]     ]] ]]]]] ]]]]]]   ]] ]]]]]]] ]]]] ]]   ]]]]
 ]]]]]     ]  ]]]]     ]]]]]      ]]]]]]]] ]]]]   ]] ]]]]    ]]]]]]]    ]]]]
 ]]]]]]      ]]]]]     ]]]]]]    ]  ]]]]]  ]]]]   ]] ]]]]    ]]]]]]]]    ]]]]
 ]]]]]]]    ]]]]]  ]    ]]]]]]  ]    ]]]   ]]]]   ]] ]]]]    ]]]] ]]]]    ]]]]
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 ]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]
 ]]]]]]]]]]]]]]]]]]]]]]]]]]]]]       Development System
 ]]]]]]]]]]]]]]]]]]]]]]]]]]]]
 ]]]]]]]]]]]]]]]]]]]]]]]]]]]       VxWorks version 5.3.1
 ]]]]]]]]]]]]]]]]]]]]]]]]]]       KERNEL: WIND version 2.5
 ]]]]]]]]]]]]]]]]]]]]]]]]]       Copyright Wind River Systems, Inc., 1984-1997

                               CPU: Heurikon Baja4700.  Processor #0.
                              Memory Size: 0x1000000.  BSP version 1.1/1.
                             WDB: Ready.

Executing startup script /usr1/epics/acav/startup.cmd ...
shellPromptSet "acav> "
value = -2146677404 = 0x800c4d64 = shellHistSize + 0x4
cd "/usr1/epics/baja"
value = 0 = 0x0
ld < iocCore
value = -2130992736 = 0x80fba1a0 = prsrv_cast_client + 0x770
ld < drvSup
value = -2131103904 = 0x80f9ef60
ld < devSup
value = -2132426208 = 0x80e5c220 = pwf_xy566 + 0x70
ld < recSup
value = -2132416016 = 0x80e5e9f0
ld < seq
value = -2130995152 = 0x80fb9830
dbLoad "default.dctsdr"
value = 0 = 0x0
cd "/usr1/epics/acav/db"
value = 0 = 0x0
dbLoadRecords "n3113.db"
value = 0 = 0x0
dbLoadRecords "n3123a.db"
value = 0 = 0x0
dbLoadRecords "n4116.db"
value = 0 = 0x0
cd "usr1/epics/baja"
value = 0 = 0x0
TSconfigure(0)
value = 1 = 0x1
iocInit "resource.def"
############################################################################
###  @(#)EPICS IOC CORE
###  @(#)Version R3.12.2patch1 Date: 1996/04/02
############################################################################
bdl1:sh: /usr1/epics/acav/db/usr1/epics/baja/resource.def: cannot open
task: 0X80fbf430 tShell
iocLogClient: unable to connect to 164.54.8.167 port 7004 because "errno = 0x33"

Unable to start log server connection watch dog
No such Resource file - resource.def
vmi4116_addr 1f045c00
entry 0 address 0x0
entry 1 address 0x0
entry 2 address 0x0
entry 3 address 0x6000
entry 4 address 0x7000
entry 5 address 0xe000
entry 6 address 0xc014
entry 7 address 0x0
entry 8 address 0x0
entry 9 address 0xff00
entry 10 address 0x0
entry 11 address 0x0
entry 12 address 0x0
entry 13 address 0x0
entry 14 address 0x2000
entry 15 address 0x2c00
Failed to set time from Unix server
0x80fbf430 (tShell): iocInit: Database Failed during Initialization
0x80fbf430 (tShell): iocInit: All initialization complete
value = 0 = 0x0
coreRelease()
############################################################################
###  @(#)EPICS IOC CORE
###  @(#)Version R3.12.2patch1 Date: 1996/04/02
############################################################################
value = 226 = 0xe2
0x80f435f0 (CA UDP): CAS: couldnt start up online notify task
OK.

Done executing startup script /usr1/epics/acav/startup.cmd
acav> dbl
C3:PSL-GEN_12DAQ1
C3:PSL-GEN_12DAQ10
C3:PSL-GEN_12DAQ11
C3:PSL-GEN_12DAQ12
C3:PSL-GEN_12DAQ13
C3:PSL-GEN_12DAQ14
C3:PSL-GEN_12DAQ15
C3:PSL-GEN_12DAQ16
C3:PSL-GEN_12DAQ17
C3:PSL-GEN_12DAQ18
C3:PSL-GEN_12DAQ19
C3:PSL-GEN_12DAQ2
C3:PSL-GEN_12DAQ20
C3:PSL-GEN_12DAQ21
C3:PSL-GEN_12DAQ22
C3:PSL-GEN_12DAQ23
C3:PSL-GEN_12DAQ24
C3:PSL-GEN_12DAQ25
C3:PSL-GEN_12DAQ26
C3:PSL-GEN_12DAQ27
C3:PSL-GEN_12DAQ28
C3:PSL-GEN_12DAQ29
C3:PSL-GEN_12DAQ3
C3:PSL-GEN_12DAQ30
C3:PSL-GEN_12DAQ31
C3:PSL-GEN_12DAQ32
C3:PSL-GEN_12DAQ33
C3:PSL-GEN_12DAQ34
C3:PSL-GEN_12DAQ35
C3:PSL-GEN_12DAQ36
C3:PSL-GEN_12DAQ37
C3:PSL-GEN_12DAQ38
C3:PSL-GEN_12DAQ39
C3:PSL-GEN_12DAQ4
C3:PSL-GEN_12DAQ40
C3:PSL-GEN_12DAQ41
C3:PSL-GEN_12DAQ42
C3:PSL-GEN_12DAQ43
C3:PSL-GEN_12DAQ44
C3:PSL-GEN_12DAQ45
C3:PSL-GEN_12DAQ46
C3:PSL-GEN_12DAQ47
C3:PSL-GEN_12DAQ48
C3:PSL-GEN_12DAQ49
C3:PSL-GEN_12DAQ5
C3:PSL-GEN_12DAQ50
C3:PSL-GEN_12DAQ51
C3:PSL-GEN_12DAQ52
C3:PSL-GEN_12DAQ53
C3:PSL-GEN_12DAQ54
C3:PSL-GEN_12DAQ55
C3:PSL-GEN_12DAQ56
C3:PSL-GEN_12DAQ57
C3:PSL-GEN_12DAQ58
C3:PSL-GEN_12DAQ59
C3:PSL-GEN_12DAQ6
C3:PSL-GEN_12DAQ60
C3:PSL-GEN_12DAQ61
C3:PSL-GEN_12DAQ62
C3:PSL-GEN_12DAQ63
C3:PSL-GEN_12DAQ64
C3:PSL-GEN_12DAQ7
C3:PSL-GEN_12DAQ8
C3:PSL-GEN_12DAQ9
C3:PSL-GEN_DAQ1
C3:PSL-GEN_DAQ10
C3:PSL-GEN_DAQ11
C3:PSL-GEN_DAQ12
C3:PSL-GEN_DAQ13
C3:PSL-GEN_DAQ14
C3:PSL-GEN_DAQ15
C3:PSL-GEN_DAQ16
C3:PSL-GEN_DAQ2
C3:PSL-GEN_DAQ3
C3:PSL-GEN_DAQ4
C3:PSL-GEN_DAQ5
C3:PSL-GEN_DAQ6
C3:PSL-GEN_DAQ7
C3:PSL-GEN_DAQ8
C3:PSL-GEN_DAQ9
C3:PSL-GEN_D2A1
C3:PSL-GEN_D2A2
C3:PSL-GEN_D2A3
C3:PSL-GEN_D2A4
C3:PSL-GEN_D2A5
C3:PSL-GEN_D2A6
C3:PSL-GEN_D2A7
C3:PSL-GEN_D2A8
value = 0 = 0x0
acav>

the new channels are available as C3:PSL-GENxxxx on fb1. We have three cards installed so far:

12bit A/D channels : C3:PSL-GEN_12DAQ1 to 64

16bit A/D channels : C3:PSL-GEN_DAQ1 to 16

16bit D/A channels : C3:PSL-GEN_D2A1 to 8

the temperature of the anaylzer cavity is C3:PSL-GEN_DAQ1 (calibrated in degC)

the driving signal for the power supply for the heater is C3:PSL-GEN_D2A1 (calibrated in volts)

here is a list of all channels of the psl subsystem. We changed the generic channel names to final names now.
Refcav channels are now C3:PSL-RCAV and analyzer cavity channels are C3:PSL-ACAV. Rest see below...

#####################
# 10W MOPA channels #
#####################
[C3:PSL-126MOPA_AMPMON]        # internal laser power monitor
[C3:PSL-126MOPA_126MON]        # internal NPRO power monitor
[C3:PSL-126MOPA_DS1]            # diode sensor 1
[C3:PSL-126MOPA_DS2]            # diode sensor 2
[C3:PSL-126MOPA_DS3]            # diode sensor 3
[C3:PSL-126MOPA_DS4]            # diode sensor 4
[C3:PSL-126MOPA_DS5]            # diode sensor 5
[C3:PSL-126MOPA_DS6]            # diode sensor 6
[C3:PSL-126MOPA_DS7]            # diode sensor 7
[C3:PSL-126MOPA_DS8]            # diode sensor 8
[C3:PSL-126MOPA_126PWR]        # NPRO power monitor
[C3:PSL-126MOPA_DTMP]        # diode temperature
[C3:PSL-126MOPA_LTMP]        # pump diode temperature
[C3:PSL-126MOPA_DMON]        # diode output monitor
[C3:PSL-126MOPA_LMON]        # pump diode output monitor
[C3:PSL-126MOPA_CURMON]        # pump diode current monitor
[C3:PSL-126MOPA_DTEC]        # diode heater voltage
[C3:PSL-126MOPA_LTEC]        # pump diode heater voltage
[C3:PSL-126MOPA_CURMON2]        # pump diode current monitor
[C3:PSL-126MOPA_HTEMP]        # head temperature
[C3:PSL-126MOPA_HTEMPSET]        # head temperature set point
[C3:PSL-126MOPA_FAULT]        # laser fault indicator
[C3:PSL-126MOPA_INTERLOCK]        # interlock control
[C3:PSL-126MOPA_SHUTTER]        # shutter control
[C3:PSL-126MOPA_126LASE]        # NPRO lase status
[C3:PSL-126MOPA_AMPON]        # power amplifier lase status
[C3:PSL-126MOPA_SHUTOPENEX]        #
[C3:PSL-126MOPA_STANDBY]        #
[C3:PSL-126MOPA_126NE]        # NPRO noise eater
[C3:PSL-126MOPA_126STANDBY]        # NPRO standby
[C3:PSL-126MOPA_DCAMP]        #
[C3:PSL-126MOPA_126CURADJ]        #
[C3:PSL-126MOPA_126SLOW]        #
[C3:PSL-126MOPA_BEAMON]        # beam on logical

#######################
# 80 MHz VCO channels #
#######################
[C3:PSL-FSS_VCODETPWR]        # 80 MHz VCO PWR
[C3:PSL-FSS_VCOTESTSW]        # enable/disable test input
[C3:PSL-FSS_VCOWIDESW]        # enable/disable wideband input

######################
# other FSS channels #
######################
[C3:PSL-FSS_SW1]            # frequency servo front panel switch
[C3:PSL-FSS_SW2]            # frequency servo front panel switch
[C3:PSL-FSS_INOFFSET]        # 21.5 MHz mixer input offset adjust
[C3:PSL-FSS_MGAIN]            # frequency servo common gain
[C3:PSL-FSS_FASTGAIN]        # phase correcting EOM gain
[C3:PSL-FSS_PHCON]            # 21.5 MHz phase control
[C3:PSL-FSS_RFADJ]            # 21.5 MHz oscillator output
[C3:PSL-FSS_SLOWDC]            # slow actuator voltage
[C3:PSL-FSS_MODET]            #
[C3:PSL-FSS_PHFLIP]            # 21.5 MHz 180 degree phase flip
[C3:PSL-FSS_MIXERM]            # 21.5 MHz mixer monitor
[C3:PSL-FSS_SLOWM]            # slow actuator voltage monitor
[C3:PSL-FSS_TIDALINPUT]        #
[C3:PSL-FSS_RFPDDC]            # 21.5 MHz photodetector DC output
[C3:PSL-FSS_LODET]            # detected 21.5 MHz output
[C3:PSL-FSS_PCDET]            #
[C3:PSL-FSS_FAST]            # fast actuator voltage
[C3:PSL-FSS_PCDRIVE]            # drive to the phase correcting EOM
[C3:PSL-FSS_RCTRANSPD]        # reference cavity transmission
[C3:PSL-FSS_RMTEMP]            # room temperature
[C3:PSL-FSS_RCTEMP]            # reference cavity temperature
[C3:PSL-FSS_HEATER]            # reference cavity heater power
[C3:PSL-FSS_TIDALOUT]        #
[C3:PSL-FSS_RCTLL]            # reference cavity transmitted light level
[C3:PSL-FSS_RAMP]            # slow actuator ramp, used in lock acquisition

################
# PMC channels #
################
[C3:PSL-PMC_SW1]            # PMC servo front panel switch
[C3:PSL-PMC_SW2]            # PMC servo front panel switch
[C3:PSL-PMC_MODET]
[C3:PSL-PMC_PHFLIP]            # 35.5 MHz 180 degree phase flip
[C3:PSL-PMC_PHCON]            # 35.5 MHz phase control
[C3:PSL-PMC_RFADJ]            # 35.5 MHz oscillator output
[C3:PSL-PMC_PMCERR]            # PMC error point
[C3:PSL-PMC_RFPDDC]            # 35.5 MHz photodetector DC output
[C3:PSL-PMC_LODET]            # detected 35.5 MHz output
[C3:PSL-PMC_PMCTRANSPD]        # PMC transmission
[C3:PSL-PMC_PCDRIVE]            #
[C3:PSL-PMC_PZT]            # PMC PZT voltage
[C3:PSL-PMC_INOFFSET]            # 35.5 MHz mixer input offset adjust
[C3:PSL-PMC_GAIN]            # PMC loop gain
[C3:PSL-PMC_RAMP]            # PMC PZT ramp, used in lock acquisition
[C3:PSL-PMC_BLANK]            # blanking input to the PMC PZT
[C3:PSL-PMC_PMCTLL]            # PMC transmitted light level

################
# ISS channels #
################
[C3:PSL-ISS_SW1]            # intensity servo front panel switch
[C3:PSL-ISS_SW2]            # intensity servo front panel switch
[C3:PSL-ISS_AOMRF]            # rf drive for intensity stabilization
[C3:PSL-ISS_ISERR]            # intensity servo error point
[C3:PSL-ISS_GAIN]            # intensity servo gain
[C3:PSL-ISS_ISET]            # intensity servo set point

#############################
# 16bit D/A channels - ACAV #
# 4116-card               #
#############################
[C3:PSL-ACAV_HEATER]            # analyzer cavity heater power
[C3:PSL-ACAV_SLOWDC]            # feedback to tidal input of other cavity

#############################
# 16bit A/D channels - ACAV #
# 3123-card                    #
#############################
[C3:PSL-ACAV_RCTEMP]            # reference cavity temperature
[C3:PSL-ACAV_RMTEMP]            # room temperature
[C3:PSL-ACAV_RCTRANSPD]         # analyzer cavity transmission
[C3:PSL-ACAV_RFPDDC]            # RF photodetector DC output
[C3:PSL-ACAV_PDHOUT]            # PDH servo output signal

#############################
# software channels - ACAV  #
#############################
[C3:PSL-ACAV_KP]                # pid loop p-gain
[C3:PSL-ACAV_KI]                # pid loop i-gain
[C3:PSL-ACAV_KD]                # pid loop d-gain
[C3:PSL-ACAV_LOCKEDLEVEL]       # threshold level below which pid does nothing
[C3:PSL-ACAV_TIMEOUT]           # pid loop sample time
[C3:PSL-ACAV_VERSION]           # pid loop software version
[C3:PSL-ACAV_DEBUG]             # pid loop debug messages on/off
[C3:PSL-ACAV_ENABLE]            # pid loop on/off
[C3:PSL-ACAV_SETPT]             # temperature setpoint
[C3:PSL-ACAV_SCALE]             # scaling factor

##############################
# software channels - REFCAV #
##############################
[C3:PSL-RCAV_KP]                # pid loop p-gain
[C3:PSL-RCAV_KI]                # pid loop i-gain
[C3:PSL-RCAV_KD]                # pid loop d-gain
[C3:PSL-RCAV_LOCKEDLEVEL]       # threshold level below which pid does nothing
[C3:PSL-RCAV_TIMEOUT]           # pid loop sample time
[C3:PSL-RCAV_VERSION]           # pid loop software version
[C3:PSL-RCAV_DEBUG]             # pid loop debug messages on/off
[C3:PSL-RCAV_ENABLE]            # pid loop on/off
[C3:PSL-RCAV_SETPT]             # temperature setpoint
[C3:PSL-RCAV_SCALE]             # scaling factor

##############################
# software channels - TIDAL  #
##############################
[C3:PSL-TIDAL_KP]               # pid loop p-gain
[C3:PSL-TIDAL_KI]               # pid loop i-gain
[C3:PSL-TIDAL_KD]               # pid loop d-gain
[C3:PSL-TIDAL_LOCKEDLEVEL]      # threshold level below which pid does nothing
[C3:PSL-TIDAL_TIMEOUT]          # pid loop sample time
[C3:PSL-TIDAL_VERSION]          # pid loop software version
[C3:PSL-TIDAL_DEBUG]            # pid loop debug messages on/off
[C3:PSL-TIDAL_ENABLE]           # pid loop on/off
[C3:PSL-TIDAL_SETPT]            # temperature setpoint
[C3:PSL-TIDAL_SCALE]            # scaling factor

last night one of the DAQ cards failed and the acav crate stopped working, so also the temp stabilization of the analyzer cavity stopped woking. I restarted everything this morning and the setpoint should be reached again by lunch time or so

i assembled everything and made all the cables for power distribution etc. I also got (the last) timing slave from Rolf.
We should get one master for all the slaves in the SB from the stuff which will be available from the sites.

The system has three A/D cards and one D/A card, including all AA and AI filters.

have put everything together. right now the frontend keeps bitching about one of the disks used for the frames, even if this disk is empty. Will take care tomorrow

 fixed it. the name is fb2 and it's ip-address 10.0.0.12

We finished the first comsol model which where we can modify the geometry automatically. The problem with comsol is that you can't export geometry data in a useful format, only binary which you can't modify. So the only way to have an adjustable geometry model is to use matlab code, and only call the comsol fem solver. A problem with matlab is that the documentation for the comsol interfacing is bad close to not existent. So e.g. if you create an object you don't know how to access the individual subdomains because you don't know anything about the numbering scheme. Here the solution was to create the geometry, import that from the matlab workspace into comsol, then use the comsol gui to create the subdomains and boundary conditions, export the stuff into a matlab file (whic you can't re-open in comsol), and copy all the information about the indexing and material property declaration back into the matlab file. Here is an example how the boundary condition syntax looks like:

bnd.Hy = {0,1};
bnd.Hz = {0,1};
bnd.ind = [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,1,2,1,1,1,1,1,1,1,1,1, 1,1,2,1,2,1,1,1,1,1,1,1,1,1,1,1,1,1];

So without the gui you can't identify the right index for the surfaces you wanna fix. But once you have done this and all the material declaration in the matlab file you can use the object created with matlab and use all the boundary conditions created with comsol and combine that. At the end the simple model for the basic cavity is 750 (!) lines of code.

Now you can do changes to the geometry within matlab as long as the indexing does not change, which is not the case for us if we move the grooves a little bit.

As we can't run a model with a good mesh on our computers (not enough memory) we tried to start comsol on menkar. Unfortunately the comsol installation does not support the integration into matlab, so you can't start matlab with the comsol functions (or better you can't run comsol which then also starts matlab and configures it in the way that you can call the comsol functions within matlab. So we can't do a good simulation and parameter sweep right now until we fix this. Jan has the same problem on his computer.

First plots will be provided tomorrow....

 Do you guys ever get those sweet FW: Fw: Fwd: RE: Re: Fw: FWD: Fw: RE: Re: emails, usually from 'friends' from Nigeria, or obnoxious family members? They can be tricky to read, since you have to scroll past a bunch of stuff.... Just sayin'.  Please carry on with your regularly scheduled Science.

There is a trick to put a message on top.
1. Change "Encoding" below editing box from HTML to plain ot ELCode
2. Put something "aaaa"
3. Revert "Encoding" to HTML
4. Now you can put whatever you like in stead of "aaaa".

fixed the "no sync" problem we had since about three weeks. It was the 100pin flat ribbon cable from the timing adapter card to the A/D card. It looks ok but has problems at one of the crimped connections. If you touch it you can toggle the connection from "OK" to "not OK" via some states in between like "OK for 5 seconds". So i replaced that cable... Now DAQ is running with 4 sensors per chamber and one temp sensor for room temp measurements. will post all the channel names later...

some new channels for the temp ctrl of the two cavities, most of them for debugging purposes only

# ACav
# Sensor1
[C3:PSL-ACAV_SENS1_VOLT]
[C3:PSL-ACAV_SENS1_KELVIN]
[C3:PSL-ACAV_SENS1_MON]
[C3:PSL-ACAV_SENS1_CAL]
# Sensor2
[C3:PSL-ACAV_SENS2_VOLT]
[C3:PSL-ACAV_SENS2_KELVIN]
[C3:PSL-ACAV_SENS2_MON]
[C3:PSL-ACAV_SENS2_CAL]
# Sensor3
[C3:PSL-ACAV_SENS3_VOLT]
[C3:PSL-ACAV_SENS3_KELVIN]
[C3:PSL-ACAV_SENS3_MON]
[C3:PSL-ACAV_SENS3_CAL]
# Sensor4
[C3:PSL-ACAV_SENS4_VOLT]
[C3:PSL-ACAV_SENS4_KELVIN]
[C3:PSL-ACAV_SENS4_MON]
[C3:PSL-ACAV_SENS4_CAL]
# Ambient Sensor1
[C3:PSL-ACAV_AMB1_VOLT]
[C3:PSL-ACAV_AMB1_KELVIN]
[C3:PSL-ACAV_AMB1_MON]
[C3:PSL-ACAV_AMB1_CAL]
# Ambient Sensor2
[C3:PSL-ACAV_AMB2_VOLT]
[C3:PSL-ACAV_AMB2_KELVIN]
[C3:PSL-ACAV_AMB2_MON]
[C3:PSL-ACAV_AMB2_CAL]
# SUM signal
[C3:PSL-ACAV_TSUM_VOLT]
[C3:PSL-ACAV_TSUM_KELVIN]
[C3:PSL-ACAV_TSUM_MON]
[C3:PSL-ACAV_TSUM_CAL]
# Stack Sensor1
[C3:PSL-ACAV_STACK_VOLT]
[C3:PSL-ACAV_STACK_KELVIN]
[C3:PSL-ACAV_STACK_MON]
[C3:PSL-ACAV_STACK_CAL]
# Servo channels
[C3:PSL-ACAV_SETPT]
[C3:PSL-ACAV_SWITCH]
[C3:PSL-ACAV_CS_MON]

# RefCav
# Sensor1
[C3:PSL-RCAV_SENS1_VOLT]
[C3:PSL-RCAV_SENS1_KELVIN]
[C3:PSL-RCAV_SENS1_MON]
[C3:PSL-RCAV_SENS1_CAL]
# Sensor2
[C3:PSL-RCAV_SENS2_VOLT]
[C3:PSL-RCAV_SENS2_KELVIN]
[C3:PSL-RCAV_SENS2_MON]
[C3:PSL-RCAV_SENS2_CAL]
# Sensor3
[C3:PSL-RCAV_SENS3_VOLT]
[C3:PSL-RCAV_SENS3_KELVIN]
[C3:PSL-RCAV_SENS3_MON]
[C3:PSL-RCAV_SENS3_CAL]
# Sensor4
[C3:PSL-RCAV_SENS4_VOLT]
[C3:PSL-RCAV_SENS4_KELVIN]
[C3:PSL-RCAV_SENS4_MON]
[C3:PSL-RCAV_SENS4_CAL]
# Ambient Sensor1
[C3:PSL-RCAV_AMB1_VOLT]
[C3:PSL-RCAV_AMB1_KELVIN]
[C3:PSL-RCAV_AMB1_MON]
[C3:PSL-RCAV_AMB1_CAL]
# Ambient Sensor2
[C3:PSL-RCAV_AMB2_VOLT]
[C3:PSL-RCAV_AMB2_KELVIN]
[C3:PSL-RCAV_AMB2_MON]
[C3:PSL-RCAV_AMB2_CAL]
# SUM signal
[C3:PSL-RCAV_TSUM_VOLT]
[C3:PSL-RCAV_TSUM_KELVIN]
[C3:PSL-RCAV_TSUM_MON]
[C3:PSL-RCAV_TSUM_CAL]
# Stack Sensor1
[C3:PSL-RCAV_STACK_VOLT]
[C3:PSL-RCAV_STACK_KELVIN]
[C3:PSL-RCAV_STACK_MON]
[C3:PSL-RCAV_STACK_CAL]
# Servo channels
[C3:PSL-RCAV_SETPT]
[C3:PSL-RCAV_SWITCH]
[C3:PSL-RCAV_CS_MON]

This morning, the PMC couldn't be locked to the laser. The FSS servo was disabled during that time.

When the gain/ RF power were adjusted, PMC was locked to the laser, but the coupling efficiency dropped from 80% to 40%.

I try adjusting the mirror, but it's not the alignment problem because I couldn't increase the efficiency.

So after the noise budget party with Jan and Frank, I check if the EOM works looking at the error signal from mixer out.  The laser frequency is scan at +/- 10V @ 100 Hz.

I'm not sure what is the corresponding freq span, but it must be less than 43 MHz(21.5 MHz x 2) because

three peaks of the signal could not be seen with +/- 10V span, so I use a voltage calibrator to slowly adjust the temperature and see the rest of the signals.

Nevertheless, the signals are there, so I try to lock the PMC again, and now the efficiency back to almost 80% again ( I have to re align again because of the earlier adjustment. The mixer out channel is monitored when I set the PMC gain to make sure there will be no oscillation.

I'm not sure what happen, loosen connectors, mode hopping in the laser, etc. I'll see if I can track this down , otherwise we could not have a stable locking system.

summary of this entry

  RefCav was not locked becase of the RFPD's input power. I haven't checked yet if it's the power supply or the cable. Now RefCav is locked.

Details

I was trying to lock RefCav again, but it didn't work.

So, I checked the error signal from mixer out, saw nothing.

It turned out that RF out from the PD has low voltage output, ~10mV.

I unplugged the cable and switch to another PD's cable along with its power supply, the DC increased to ~300 mV, a good sign.

Still, no error signal from Mixer Out Channel, nothing at all.

The control loop is not closed. Now 35.5 MHz LO is connected to the EOM, and to the servo card, LO input channel. The RF signal goes to the PD input.

We should be able to see the error signal from this setup.

**********The loop in the medm screen must be enabled in order to see the error signal******.

     EOM  -----------------BS--------------------- [ RefCav ]

        |                           |

        LO                       PD

        |                             |

        -------- X -------------

                   |

                   --->  Error signal

  I mix the signals from PD and LO by a Mixer [Minicurcuit ZFM 3 S+] and see something. It's a peak crossing zero at center instead of three peaks like the error signals. 

So I'm not sure what I'm seeing, but it seems that Mixer Out channel from the spare FSS servo might not working. I switched back to the first card, and now I see the error signals.

I set the RF to 6.1 V which corresponds to 97 mV of the error signal's P-P height.

Phase adj: is 4.5122 V,

phase flip: 0

Gain: [not set yet]

      All these values are saved in startup

  To summary, RefCav was not locked becase of the power cable which I haven't checked yet if it's the power supply or the cable. Now it's locked.

I'll set the gain tomorrow and see where I can connect the slow actuator for the laser driver. Right now I can't find where the servo for slow actuator would be.

I moved the laser driver to the electronic rack and it should stay there for the final setup.

A cable for interlock is made and connected to the laser driver.

A cable for slow actuator is also made and connected. Now we can use the medm FSS screen instead of the voltage calibrator

to adjust the NPRO's temperature (slow actuator.)

I went to 40m lab for a measurement

I'm currently working on measuring the phase noise of the Marconis at 80 MHz - I will be moving on to 160 MHz soon. I'm also working on learning how to make the computer do what I want it to, but I should be done with the measurements and post graphs later today. Then depending how long the measurements take today, I'll start measuring our Marconi and then move on to the VCO tomorrow and should be able to modify the VCO by Friday. One of the main things that's slowing me down is getting comfortable with processing the data on the computer.

Also, I've been having problems getting the Marconis to lock at any feedback gain below 2000. I've been using that to stay consistent and get a good lock between the two, because with lower gain there was always a sneaky little sine wave making it through the feedback loop and into the locked signal. I've accounted for this in the calibrations I've been making, with a UGF of around 1000 Hz.

1) I just found out that the pbs + 1/4 waveplate in front of RefCav is not well aligned, so the length,as seen by the beam, is not 1/4 wavelength.

    Hence, the polarization is not turned 90 degree after double passing, and

    The reflected beam can go back to the laser and causes the power fluctuation we saw before.

    When the beam is blocked anywhere before RefCav, the beam output from PMC is very stable.

    I adjusted the PBS's angle and reduced the reflected power. Now the input power to PMC can go up to 50 mW without any fluctuation. 

2) I re-aligned the beam into RefCav, with Frank's help on gain adjusting,

    the transmitted power seems to be more stable. RefCav transmitted power RIN is posted below. I'll post the comparison between result at 40m soon. From a quick glance, RIN from 40m is at least 2 order of magnitude below

our result.

3) The PID control for slow actuator is up. I was adjusting it, but the medm screen was frozen.

    I reset it, and set the PID control (only P-part). The current setting for Proportional control(C3:PSL-FSS_SLOWKP) is +0.41.

Frank and I made connectors for the VCOs so we don't have to have so many cords connected inside the VCO box. We also measured one of the VCOs and established it is a lot noisier than our Marconis. We'll work on modifying it and see how that changes it. Meanwhile we'll test the other to see if it's at the same level or different.

Also, I've now learned how to correctly calibrate the phase noise so I will hopefully be able to go back and calibrate a lot of the data that I have so we have a better idea of what is actually going on.

I replace R3 and R7 with thin film resistors (according to LISO they have the greatest contribution of the resistors at lower frequencies) and re-measured the electronic noise of the driver. It was almost identical to the noise I previously measured, and so for now am not going to replace the other resistors because it does not seem to have a large effect.

I have been playing around with the LISO model more and will hopefully have an easy-to-use version to upload soon. I'm going to work with more of the data that I have to see what it tells us and will post various graphs tomorrow.

I re-measured the noise at TP7 using the Busby Low Noise Box and measured the instrument noise of the box - the noise is lower at high frequencies, but much higher at low frequencies. There is a possibility some of this came from old batteries - they measured 7.4 V, but we were 2 short in 40m so I couldn't replace them. I will try to get new batteries tomorrow and see if that affects it at all.

I also changed the couple of things that were wrong with the model and have the revised model as well as its resultant graph attached.

I subtracted the noise of the other amplifier from the previous measurement of the noise at TP7 and compared it with the new model and they line up almost perfectly except around 10 Hz, where they're a little off.

looks quite good.

You can take the two new batteries out of the FET preamp box if you can't find more (the ones we replaced last week).

i had a quick look onto your new data. If you subtract the busby box noise floor from the new data you are almost there...

I replaced the batteries of the Busby box today to see if that reduced noise. It did not. Measuring the instrument noise and TP7 noise gave exactly what I got yesterday with the old batteries. I subtracted the instrument noise to plot against the model again and got basically the same graph as yesterday.

I also tried comparing the phase noise coming from the electronic noise against the total noise of the VCO. The total noise of the VCO was apparently below that of the electronic noise. I'm wondering if it could have been the fault of all the ground loops, since removing almost every cable changed the graph of the electronic noise so much. So at some point soon I would like to re-connect the entire VCO and measure the phase noise again, making sure I remove every unnecessary cable. This part confuses me though - all the schematics label the connecting resistor as 0, so I'm not sure if there is a 0 resistor or if it's a value that I don't know?

there are 0 Ohm resistors, but you can also make a simple short between those two pads

i don't understand the third graph.  Looks like the blue data is the frequency noise calculated from the electronic noise with your 680KHz/V coefficient. The green one looks like phase noise, so i think you have to convert one of those into other units

 Looks like I made the third graph without really thinking about what I was doing. The y-axis is labeled completely incorrectly, the blue data is frequency noise calculated from the electronic noise, and the green data is the phase noise from the VCO. So, after thinking about what I was doing, I converted the electronic noise into phase noise and graphed them together (with correct axis labels). They look more similar now, but I would still like to measure the VCO without the extra cables. I'll try connecting the VCO and measure again.

i prepared a master screen for the refcav experiment.
This main screen contains all important numbers to figure out what the status of the experiment is.
It also contains several stripcharts which monitor important values like temperatures of the cavities, transmitted power levels etc over time.
It also has several buttons which link to the individual sub-screens which already exist for our subsystems.

While I guess it's a nice idea to put a Success = 100 meter on all of our MEDM screens for motivational purposes, what are the units on this one / the meaning of it?  Everything else makes sense (except maybe for the strength....are strength and success related?), but the success is confusing.

Leave Frank alone!  His strength is already down to 47 and his PMC has -2mW of anti-energy coming out of it.

i don't know the units for the strength, but it's showing how good the reception of the signal is.I can't be dBm or something like that, so i don't know what units they use for that kind of quality signal.

The success rate is basically percent. Same situation here, there is no explanation for this signal, but it goes from 0 to 100 so it's percent.
If the value drops below 100 that basically means that the sensor is close to the range limit or the batteries are empty and so the communication is bad and we are loosing some data points...

the reason for some funny numbers like getting energy out of the PMC is that most of those channels are not connected or not calibrated yet. The PMC refl power is an open input

Today I aligned the AOM so that I could align the analyzer cavity to lock the cavity. We already aligned and locked the PMC last week so we had a beam to work with. The AOM is now aligned and the beam coming from it is aligned into the analyzer cavity. We scanned the cavity to find the mode we want and currently the output of the photocell is being mixed with the local oscillator to find the error signal. It's not quite how it should be right now, so we will look at it tomorrow to figure out what is wrong. Then we can connect it to the PDH servo and lock the cavity!

I also did some cable-management. They are now neatly organized and held in place by a large number of zip ties so they don't get in the way of everything else! The cameras are now connected so that we can see the beam from the PMC, analyzer cavity, and reference cavity.

The PMC is still locked (except when we do something to unlock it) and both the analyzer cavities and reference cavities have the ability to be locked. We have not locked them simultaneously yet but will be working on that so we can get a beat. We connected the VCO driver to the AOM for the analyzer cavity and got it locked.

A preliminary calibration for the photodetectors in the path of the transmitted light from the reference cavity has been calculated, although changes in the next day or two might change it, so it has not been put into the computer.

The table by the cavities is now very pretty . Until we fill all the space we just cleared with everything we need to beat the two beams together!

Preparations for that will be started tomorrow by putting the correct optics in the path of the transmitted light of the analyzer cavity and better aligning those in the path of the reference cavity's transmitted light.

Also, as an extra note, last week we calibrated some inputs, so we no longer have anti-energy reflected from the PMC! In fact, at this moment, we have 1.4mW. Success is still 100 and strength is down to 44! Guess it's time for dinner.

we locked both cavities individually. Right now we can't lock both at the same time as the temperature stabilization loop isn't working. Something is wrong with the network.
We don't see the channels taken with the realtime system (running on fb0). Something is wrong with the broadcasting of the epics channels.
So we decided to lock them individually for now and start setting up the beat measurement as far as we can. The problem might be solved until we really need both at the same time.
We also add some more channels for the second cavity, RFPD DC out and transmitted light in order to monitor the quality of lock over time.

Both the analyzer cavity and reference cavity are able to be locked, and were simultaneously locked for a while yesterday . However, the temperature control loop is not working because the computer is not seeing the temperature data, so it didn't stay locked . But now we know it's possible !

The mirrors, beam splitter, and photodetectors are set up and aligned to measure the beat of the two signals and I am currently working on mode matching to get the beams the same size at the photodetector.

FSS_RCTRANSPD and ACAV_TRANSPD have been calibrated:

FSS_RCTRANSPD = 1.98 mW/V

ACAV_TRANSPD = 2.18 mW/V

All of the optics were set up in the path of the transmitted light from both cavities. Each path needed both a quarter wave plate and a half wave plate to be able to get the s polarization needed by the beam splitter. This solved problems we had earlier with the 50/50 beam splitter doing more like 25/75!

For mode matching, 2 lenses were placed in the path of the RCAV, one with a focal length of 175mm at a distance of roughly 7.5 inches from the first mirror and the other with a focal length of 200mm roughly 5.5 inches before the second mirror. This gave a waist of 224 µm 7.5 inches after the beam splitter.

The ACAV got only 1 lens, with a focal length of 200mm, 2.5 inches before the second mirror, with a waist of 208 µm at the same distance (7.5 inches from the beam splitter).

The first photodetector was placed with a mirror (for better alignment) above the beam splitter, and the other was placed after 2 mirrors and another lens in the other path. The second photodetector has a smaller detector area, so we ideally would like the waist at the detector to be under 100 µm. To make the beam smaller, we used another lens with a focal length of 30mm roughly 2 inches after the second mirror. This still leaves the beam a little larger than we'd like (it's very sensitive to alignment), but it will be fine for the moment.

The two cavities have still not been intentionally locked simultaneously. Yesterday, they differed by roughly 17 MHz (if I remember correctly) and so they were being heated overnight so their temperature can stabilize and we can see if they are closer today.

The cavities were still too far off to lock simultaneously, but they should hopefully be better today.

Instead, we played with the Wenzel BluePhase 1000 phase noise test system.

Following the directions in the manual, we locked an IFR/Marconi 2023A to an IFR/Marconi 2023B, calibrated according to the manual, and got a curve very similar to what we had before . This means it's probably working correctly!

So then, just to be adventurous, we decided to connect the VCO in place of the 2023B to measure its phase noise. Apparently that was too adventurous for the BluePhase 1000 . We couldn't lock it (with the feedback loop going to the 2023A) with any input range below roughly 100 kHz and the output (after calibration as per the manual) was a flat line. After readjusting cables and reconnecting cables and finally reverting back to the 2023A vs 2023B to make sure the machine still worked, we decided the unity gain frequency was probably pretty high and the manual calibration did not take that into account. So we used a swept sine measurement to find the transfer function of the system with the VCO connected and locked. The UGF was around 5.3 kHz with the 100 kHz input range . This means that the calibration doesn't account for everything when the UGF is high . But it also means we may have found the problem with our data when the VCO is connected ! So I have to take the data we have, apply a zero at 5.3 kHz, and see if that gets it to line up correctly.

Meanwhile, we installed a program on the computer that, when connected to the BluePhase 1000, can control all the knobs and buttons and locking remotely. And we discovered you can do more on the computer than with the switches on the front! Like change the capacitor value.

So the summary of yesterday's activities is: don't ever completely trust the calibration the manufacturers tell you to use. They might not be taking something (UGF) into account.

And the calibration as per the manufacturers:

1) Adjust the offset until exactly 1 period is displayed on the oscilloscope

2) Divide the time divisions on the oscilloscope to 1/100th the original (this gives 0.02Pi radians)

3) Measure the voltage difference across the two ends of the line

4) Calculate your slope! (gives V/rad)

5) Noise [dBc/Hz] = [PSD]-[20log(slope)]-[amp gain]-[correction for SSB measurement]

Yesterday we set up channels to record the noise of the locked signal generators. After a while playing with channels and filters and everything, the results are that the missing factor might be somewhere in the calibration of the data in 40m because this data fits where we would expect it to, slightly above the electronic noise converted to phase noise at low frequencies and much higher at high frequencies.

I tried to check the calibration in 40m this morning, but Jenna had the rubidium clocks hooked up and was collecting data with that, but I might be able to go back this afternoon and get something to see if it's in the calibration of rad/count.

We got both cavities locked today!

They stayed locked for at least an hour and were still locked when we left. Hopefully they'll still be locked tomorrow morning!

We aligned both beams into the photodiode (they were already pre-aligned) and maximized the alignment to get the largest signal out of the photodiode. We locked the signal from the photodiode with the IFR/Marconi 2023B signal generator and took some measurements of noise and transfer functions to determine UGFs, which I will post graphs of when I put them together. The plan is to let the temperatures really settle down (they were still settling a bit when we left) and take a good measurement of the noise and measure the transfer functions to determine UGF tomorrow. Then we will pull everything apart (not really) to replace the two cables that have extensions on them to see if something in the connection can be fixed to give better stabilization.

*I added a graph of the noise we measured yesterday at 3 different times*

we have probably some minor network problems which causes some channels not beeing available at all times even on the same computer.

example:
if you open the Striptool and Probe at the same time and access the same channel, one of the tools can see the channel, the other doesn't.
Or one tools sees a different value, e.g. if i change the setpoint of the temp loop, probe still sees the old value, but the Striptool already the new one.
Sometimes it helps if you close the application and after restarting it everything is fine. Same for the framebuilder. Sometimes some of the channels get lost.
I don't know where it comes from. It happens randomly to any of the channels. It's not the traffic on the network, but could be some routing problem.

Peter and i solved the problem with the fss loop today, but here the long story:

The problem was that the loop was much more stable without the PC connected, so only the PZT of the laser was used as an actuator so far. Already some time ago i thought it might be the wrong sign for the PC and so i tried to change the sign of the loop by changing the two jumpers at the output going to the fast actuator and changing the sign of the error signal, but i never got it to lock in that configuration. So i though the other, previous configuration must be the right one, as it is locking. Later Tara had the same problems. The problem was that if the PC was connected the stability didn't increase and it even seemed to be more unstable using the PC in addition.

So in fact, the sign we used so far was the wrong one. But the problem was that changing the sign of the fast actuator and then flipping the error signal sign didn't work because the other (right) jumper settings don't work ! There is no feedback to the PZT of you change the two jumpers to the other orientation !! That's why it never worked with the right jumper positions.

As we figured out that this might be the problem i've build a BNC adapter changing the sign at the input of the laser and here we go, it's working now  So something is wrong with this board . I will figure that out later what exactly is broken on that board.

will measure the ugf of the fss loop tomorrow...

We were going to work on building a metal box around the cavities, but they didn't have enough sheet metal and would have to order more, so Frank is working on a design for the box and will order the metal.

Instead, we got free foam! Someone ordered too much, so we took a sheet to build a new box around the cavities to see if it would help with stabilization.

After a while spent cutting the foam, we built a box!

And it is very happy to stabilize the cavities. We placed some foam bits on top to make a makeshift lid, and will use another foam sheet today to cut a real lid that fits on the box.

i tried a couple of things today to figure out what determines the low frequency noise level of the beat measurement.
I did the following steps, nevertheless the noise level didn't change:

• re-aligned everything starting with the PMC
• coupling into the cavities is >90%
• matched power levels in both paths to match power at RF photodetector
• re-positioned the RF photodiodes for locking the caviries
• added beam dumps for beams reflected from RF photodiodes
• optimized overlap of both beams on RF photodiode (beat)
• changed mixer from 7dbm model to 13dbm model
• removed cable going to DAQ from DC output of RCAV RF photodiode as it is causing ~36MHz oscillation of RF PD (even with no light)
• changed gains for both loops, ACAV and RCAV
• added first QPD at pick-off right in front of periscope into chamber for RCAV to check pointing

things to be checked tomorrow:

• power fluctuations of beams into both cavities
• power fluctuations of transmitted beam
• pointing of both beams (should also show up in power noise spectrum in transmission)
• measure TF of all loops with current setting for noise estimation

other things to change:

• move temp readout to VME based stuff
• rename VCO input monitor signal channel name
• remove PSL RT stuff from fb0 to see if networking problems are caused by that
• replace current cables for temp readout due to loose connection somewhere on table
• check ACAV RF photodiode
• change PID controller variable names in order to add other software loops like feedback from VCO input signal to RCAV temp setpoint. Right now we have already 4 software loops:

1. feedback to laser for RCAV using FAST actuator signal
2. temp ctrl for RCAV
3. temp ctrl for ACAV
4. feedback to laser temp for ACAV using VCO input signal (used to track ACAV temp tuning to match RCAV resonance)

 Frank showed me that the RIN level from PMC is too high and caused by back reflection. 

PMC's psd is reduced by blocking the beam going to ACAV and RCAV.  This can be seen

on SR785, by blocking the beam.

So I removed PBS in front of the laser, and replaced it with a Faraday isolator. 

The isolator is temporarily mounted on a post, we will use a more rigid  V-shape block holder later.

The isolator shifts the beam path a bit, and the beam is needed to be re-align to the PMC. 

I couldn't finished it by Friday night, I think Frank re-aligned it already.

I'll measure RIN  and compare them again.

after a lot of test it turned out that the optically contacted QWP/PBS combinations used for the reference cavity so far are very bad alligned.
We tested two out of three we have in the PSL lab and both are bad, meaning about 10% of the linear polarized light entering the PBS are not converted into circular polarized light and so not reflected when comming in the reverse direction. By replacing the optically contacted version by individual PBS and QWP the amount of wrong light dropped by a factor of 100 or so.

Replacing the bad optics should reduce the effect from backscattered/reflected light, which increases the RIN a lot at low frequencies. It doesn't seem to be the laser itself, as with none, one or two FI the spectrum seems to be the same bad level when light is reflected back into the PMC. It looks like the source is the PMC itself or it's control loop.

So, Tara is replacing the bad ones and re-aligning everything. Temp is good, both cavities are resonant at the same time so i hope we can get new/better data tomorrow.

Plot from yesterday measurement. The new result is in red.

The data is measured from the feedback signal in PLL loop. Its UGF is about 53 KHz.

The data is calibrated to Hz/ rt Hz unit by a factor of 71.3 kHz/ volt.

 A photodiode for measuring the laser power reflecting from the Faraday isolator's in port is added.

The cable is prepared and connected from the PD to DAQ.

The channel name will be C3:PSL-NPRO_PWRMON. 

The FSS servo is not working. When SLOWDC which controls the NPRO temperature is brought to near resonance,

it falls off the lock when we enable the loop. So it's a debugging day.

First, I aligned the beam on RFPD, making sure that the beam is on the center, and align the beam to the cavity.

The signal from transmitted beam oscillates a lot. The gain was too high

(This is surprising, we haven't changed any power but the gain is too high already.) 

the set up is changed as follow

common gain, 16  --> 7

Fast gain,   15 --> 14

RF power  7.0 --> 7.2

Phase Adj  4.5 --> 3.92

Then I checked the error signal from MIXER OUT channel on FSS card. The signal looks fine.

The DC level is ~ 17 mW, peak to peak level of the carrier is 160 mV, and 39 mV for sidebands.

[the setup is:

RF power 7.0 V
Phase adj 4.5 V +180 flip]

The transfer function between In2 and fast mon seems fine.

---------------------------------

Now the loop can be locked, but when FSS_FAST gets lower than -2 V. It runs away and lose lock.

This does not happen when it goes to plus sign. it can go up to 5 or 6 V before losing lock.

So we increased the RF power to maximum (10 V) which increases the error signal pk-pk to 394 mV.

FSS MON seems to stop railing, I'll adjust the gain setting again to minimize fluctuation in mixer out. 

Today I measured open loop transfer function of PMC loop.

The measurement has two parts.

First the swept sine signal is sent to FP2 test point, TP4 is connected to A, TP3 is connected to B,

the magnitude, B/A, gives us [C][D][E] .

For the second part, the swept sine is sent to ext DC channel,

TP3 is connected to A, and TP4 is connected to B.

this is the TF of [F][A][B]

======================================================================

 [A]--<FP2>-----[B]-----{TP4} ------[C]-----[D]---<Ext DC> ----[E] ---- {TP3}----[F]-----> back to [A]

======================================================================

The magnitudes and phase from both measurements are added up

to get the whole open loop TF of PMC loop [A][B][C][D][E][F].

UGF is ~1k Hz.

PMC setup

Gain 30dB (mzx)

LO PWR 0.585

Power input 30.9 mW

PMC_PHCON 2.5 + 180 flip

PMC_RFADJ 4.0

I'll verify that the schematic matches up with the real circuit we are using.