Valid for RUN 7                                                                                                                                                                   3/1/2007

 

TPC

SHORT OPERATIONS MANUAL FOR

DETECTOR OPERATORS

(written by Blair Stringfellow)

 

Table of Contents

 

                1. Rules of operations:

 

                                1.1 FEEs………………………………………….pg 2

                                1.2 HV……………………………………………pg 2

                                1.3 Frequency and method for pedestal run………pg 2

                                1.4 Frequency and method for laser run………….pg 3

                                1.5 Frequency and method for pulser run………...pg 3

 

                2. Operations for various subsystems:

 

                                2.1 Boot up of control computer…………………..pg 4

                                2.2 VME crates & Processors……………………..pg 5-6

                                2.3 Interlocks……………………………………...pg 7

                                2.4 FEE’s & MWC FEE’s………………………...pg 8

                                2.5 Gated Grid…………………………………….pg 9-10

                                2.6 Cathode and field cage………………………..pg 11-13

                                2.7 Anode & trips…………………………………pg 14-19

                                2.8 Laser…………………………………………..pg 19

                                2.9 TPC alarm handler…………………………….pg 20

 

                3. Alarms:

 

                                3.1 Gas alarms……………………………………..pg 21

                                3.2 Water alarms………………………………….. pg 21

 

                4. Call list of experts…………………………………………pg 22

 

                5. TPC state table for various runs…………………………..pg 23


1. Rules of Operation

 

                1.1 FEE’s (Front End Electronics)

 

There are two sets of FEEs (and RDOs) for the TPC:

                1. The pad plane FEE’s

                2. The MWC FEE’s that terminate the anode wires.

 

                Both sets are cooled by the TPC water skid (nominal temperature = 75 F). The temperature is monitored by a computer program which periodically reads out 120 thermistors mounted on the FEE and RDO cooling manifolds. These temperatures are displayed in a GUI available from the top level TPC GUI.

These temperatures are also watched by the TPC alarm handler (alarm = 80 F).

 

RULE 1: If the overall average reads > 80F, power down the FEE’s and MWC FEE’s until the cooling problem is solved.

 

The TPC water skid exchanges heat with the STAR Modified Chilled Water (MCW). To maintain the TPC

at 75, the MCW must typically be < 64F. A problem with the TPC cooling water temp can usually be traced to a MCW problem. Note also that the FEE’s are interlocked to the TPC water skid – a loss of flow will automatically turn off the FEE’s.

 

Because of an uncertainty about induced currents associated with the magnet, we also have:

 

RULE 2: Turn off all FEE’s and MWC FEE’s when the magnet is being ramped up or down.

 

 

                1.2 HV

 

Ultimate responsibility for the safe operation of the TPC rests with the Detector Operator! For this reason,

the final authority for turning on (and off) the HV also rests with the detector operator. To protect the TPC,

the most important rule is:

 

RULE 3: The anode and cathode HV are to be kept OFF UNTIL RHIC has stable stored and cogged beams. There are NO exceptions to this rule except by explicit permission from Blair Stringfellow or Howard Wieman.

 

We have seen both field cage sparkdowns and multiple anode trips that were clearly beam induced. This can happen at any energy and any intensity. Note that this means turning ON the HV AFTER the beams are stored AND turning OFF the HV BEFORE the beams are dumped. It is the detector operator’s responsibility to encourage the shift leader to always get advance notice of a beam dump.

 

                1.3 Frequency and method for Pedestal Runs

 

It is now possible to save the TPC pedestal values on disk, so a DAQ reboot doesn’t necessarily mean having to take a new pedestal run. Pending further study, it is recommended to take a pedestal run at least once per shift. Pedestal runs are configured through trigger and DAQ. Number of events > 250.

The state of the TPC should be:

 

                FEE’s and MWC FEEs ON

                Gated Grid ON

                Cathode HV on or off

                Anode HV at pedestal values or less (pedestal values are Inner = 700V, Outer = 900V)

 


                1.4 Frequency and method for Laser Runs

 

Laser runs are used to check the TPC drift velocity, and should be taken once a store, usually 1 hour into the store. You should stop the current physics run and make a dedicated laser run. (Include Trigger, DAQ and TPC in run control – NO other detectors.) The DAQ rate for a normal laser run should be 10 Hz, triggered by the free running laser. To turn on the laser see the separate laser operations manual. The TPC’s operating parameters (HV) are the same for laser runs and   physics runs. The TPC drift velocity is automatically calculated online from event pool events. The result shows up in the online histograms. Typically, ~ 2000 laser triggers are sufficient to calculate a drift velocity. For long stores (typical of pp)

take a laser run every ~ 4 hours after the first one.

 

                1.5 Frequency and method for TPC Pulser Runs

 

Pulser runs are used to check the TPC FEE’s and RDO’s. They can be taken at any time by reconfiguring trigger and DAQ for a pulser run. A pulser run should be taken once a day, typically during times with no beam. For a pulser run:

 

                Use the LOCAL oscillator (not the RHIC clock)

                Make a TPC pedestal run, then a pulser run.

                FEE’s and MWC FEE’s ON

                Gated Grid On

                Cathode On or Off

                Anode Off or On at or below pedestal values (Inner = 700V, Outer = 900V)


2. Operations for Various Subsystems:

 

 

                2.1 Boot & setup of Control Computer

 

All operations for the TPC are controlled from the PC chaplin.starp.bnl.gov located in the STAR control room. To get started, log on to Chaplin (username and password posted on the monitor). After boot, double click on the desktop icon “TPC_TOP_startup.xs”. This will automatically log on to the slow controls computer sc3.starp.bnl.gov and start the TPC top level control GUI, which looks like: (this is slow – WAIT)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


 To simplify the controls for the various subsystems. Chaplin is set up to run 9 virtual desktops, each labeled for a specific function:

 

                1. Anodes

                2. Cathode and field cage

                3. Gating grid

                4. FEE’s

                5. Laser

                6. Gas system

                7. Interlocks

                8.VME status

                9. Pad monitor/General Use.

 

You can switch between desktops by clicking on the appropriate number in the virtual desktop keypad in the upper right corner of  the screen. Switching desktops will reduce clutter and separate each TPC control.

 

After running the EXCEED session TPC_TOP_startup.xs, the top level TPC control GUI will be placed automatically on all 9 desktops.

 

                                                               

 

 

 

 

 


                2.2 VME Crates & Processors

 

All TPC functions are controlled using VME CPU’s which are located in VME crates on the 2nd floor of the south platform. These crates can be remotely turned on/off using slow controls. To check the status of the crates, click on desktop 8 and select “2nd floor VME”. This will bring up the VME control GUI:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Note that crates are labeled by function, canbus number and rack number. Crate 51 is for slow controls and should not be powered off. The green dot indicates that the crate is powered on (thus, #55 is off.) To turn a crate on (or off), click and hold on the purple button, drag down and release on the “VME xx” button, where xx is the canbus number. This brings up the control GUI for that crate:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


To turn the crate on, click the “ON” button. The fan speed, voltages, currents, and temperatures will be indicated. Kill the window when done.

Before proceeding, make sure all crates for the TPC are ON.

VME PROCESSORS:

 

Typically, there is one VME processor for each TPC control task, and one CPU per crate. (Some crates may have two processors.) These processors run VxWorks and boot from the main slow controls computer (sc3.starp.bnl.gov). There are two connections for each CPU, one via ethernet and one through a terminal server. Remote login over ethernet is reserved for the slow controls expert. If problems develop with a CPU it can be rebooted by four different methods:

 

  1. Cycle the power on the crate. (Not recommended, but sometimes necessary.)

 

                                                                OR

 

  2. Push the sys reset button on the crate’s control GUI – this reboots all processors in that crate.

 

                                                                OR

 

3. For the Gated Grid and Inner & Outer Anodes, there is a reset button on the main GUI. Clicking on this button will reboot the processor. (These three processors crash most often.)

 

                                                                OR

  4 Login via the terminal server as follows:

 

                On the CHAPLIN desktop, double click on the “putty.exe” icon. In the putty dialog box, double click on the session “sc3.starp.bnl.gov”. At the sc3 prompt, type the username and password (same as for Chaplin).

 

                On sc3, type telnet scserv xxxx, CR where xxxx is the port number for the processor.(see below)

 

                After you are attached to the processor, hit CR. To reboot, type “reboot,CR”

 

                After the reboot, exit the session by typing “CTRL ]” simultaneously to get back to the telnet prompt. Type quit to get back to sc3. Type exit to logoff.

 

                ALWAYS release these terminal server sessions when you are done!

 

The current CPU’s and port assignments are as follows:

 

1.Field Cage Readout                         Port 9001              Crate 56                                Rack 2A4

2. Gated Grid                                        Port 9002              Crate 54                                Rack 2A6

3. FEE Power supplies                         Port 9004              Crate 58                                Rack 2B5

4. Cathode HV                                     Port 9005              Crate 57                                Rack 2A3

5. Inner Anode HV                              Port 9006              Crate 52                                Rack 2A7

6. Ground Plane Pulser                       Port 9011              Crate 55                                Rack 2A5

7. Interlock/TPC temperature           Port 9012              Non Canbus         Rack 2A7   RPS3 Plug A4

8. Outer Anode HV                             Port 9013              Crate 59                                Rack 2A6

9. Platform Hygrometer/TPC gas     Port 9015              Crate 58                                Rack 2B5

10. Autoramp programs for anode & cathode – STARGATE processor in DAQ room rack  DC2

at the bottom of the rack (push the reset button)

 

Lecroy serial session for inner sectors              Port 9037

Lecroy serial session for outer sectors             Port 9038

Lecroy serial session for FTPC anodes            Port 9023

 

When a VME processor reboots, a grey MEDM Message Window will pop up with the message “network connection lost”. Close this window. Also, the relevant GUI will turn white until the processor reboots.
                2.3 Interlocks

 

The interlock status for the TPC can be checked from the control room by selecting the “Interlock” button on the top level GUI. (This is a representation of the Allen-Bradley (AB) panel which is located in Rack 4 of the gas mixing room.) The panel looks like:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


The round lights across the top and the top row of rectangular lights are status lights for the inputs to the interlock panel. The bottom two rows of rectangular lights show the status of the outputs to the various subsystems of the TPC. Under normal circumstances, ALL lights should be green. In the above example, the gas system is off, so no system can run.

 

Note that if, during a run, one or more of the inputs changes from OK to “not OK”, the AB PLC will take automatic action to shut down the affected subsystem or HV. NO OPERATOR ACTION IS REQUIRED.

 


                2.4 FEE’s and MWC FEE’s

 

To operate the main TPC FEE’s and RDOs, go to desktop 4 and select “FEE Voltage” on the toplevel GUI. The FEE control looks like:

 

                                                                                                                                               

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

To turn all the FEE’s and RDOs on click on the “global” on button. Each of the supplies will turn green in turn. There are also “on” buttons for each rack (= 3 supersectors), east and west ends, and individual supplies. To turn off, click  the corresponding “off” button.

 

The global on button will also turn on the MWPC FEE’s, shown across the bottom of the GUI. To turn on the MWPC FEE’s only, use the MWPC ON button at the bottom of the GUI.

 

 

  Remember – the MWPC FEE’s should be on for ALL runs!

 

Each TPC RDO is read out by a DAQ receiver card. These cards are in VME crates and are visible from the control room. During normal data taking the LEDs on the receivers flash green as data comes in. It sometimes happens that a DAQ receiver/RDO pair will hang. This will be indicated by a slowing or stopping of DAQ and red lights on the affected receiver. For the TPC there are 12 crates of receivers with

12 cards per crate. The crates are labeled TPC 1,3,5..... Since there are 6 RDOs per TPC supersector (inner + outer) each crate reads out 2 supersectors. You can sometimes clear the bad RDO/receiver pair by cycling  the power for that RDO. STOP THE RUN FIRST!  As an example if the 8th card in crate TPC 3 is hung you would cycle the power for RDO S6-N2. (Crate 3 reads out supersectors 5 & 6. The first 6 cards from the left are 5-1 through 5-6, the next 6 cards are 6-1 through 6-6). If the run still freezes after cycling the power and also rebooting DAQ it may be necessary to mask out this RDO/receiver in the run. The shiftleader has instructions for this.


                2.5 Gated Grid

 

To turn on the gated grid, go to desktop # 3 and click on “Gating Grid” on the top level GUI. This brings up the main gated grid GUI:

 

 


     

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1. Click on the “Default Sequences” button. This brings up the control screen:

 

 

  

 

 

 

 

 

 

 

 

2. Click on the “Grid On” button. This will run a program to set all the GG power supplies. You should see the message “Downloading Setpoints”. It should take ~3 minutes for all sectors to come up to voltage. When the gated grid is ready, all sectors on the main screen turn green:

 

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3. If the status remains “idle” after clicking on the “Grid On” button, you will have to regain control of the program. First, click and hold on the “Reconfigure” button, drag down to “Recover control” and let go. Try the “grid on” button again. If this still doesn’t work, reboot the crate by clicking and holding on the “Reconfigure”, drag down to “Reboot control crate” and let go. The processor should reboot.

 

NOTE: Before rebooting the Gated Grid processor run the TPC anodes to zero if there is beam in RHIC. Rebooting causes the GG voltages to turn off, causing high currents in the TPC.

 

4. To check on the voltage setpoint for a sector, click on the button for that sector. This brings up the control window:

 


 

 

 

 

 

 

 

 

 

 

5. The display for the main GG panel is color coded – a sector whose voltage deviates 2% from the setpoint will turn yellow, 5% will turn red. You will also get an alarm from the TPC alarm handler. For yellow, the run can continue – for red, STOP the run.

 

6. To turn the GG off, click the “Grid Off” button in the Default Sequences window.

 

7. For normal running the gated grid stays ON all the time, even when there is no beam.

 


                2.6 Cathode HV & Field Cage

 

AUTORAMP MODE

 

1. To turn on the cathode HV using autoramp mode, first go to desktop # 2 and click on “cathode” to open the cathode GUI. Also click on “Field Cage” to open the field cage current read back screen.

 

2. The cathode control looks like:

 

 


  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3. Make sure the slider switch is set to 0 and then click the HV button if the HV is off. The HV will turn on and the light will go to red. Note that it is not possible to turn the HV back off again by pushing this button!

 

4. Make sure that the RHIC beam is stored, cogged and stable before proceeding.

 

5. Click on the “Auto-On” button. This brings up the GUI:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

6. Click the “ON” button. The program will then automatically do the following:

 

                Ramp to 10 kV

                Check that the four field cage currents are all equal.

                Ramp to 20 kV

                Again check the currents

                Ramp to final HV (currently 28 kV)

                Check the currents

 

This process takes ~ 10 minutes.

 

If  the currents are not equal, the program will stop and ramp the HV back to 0. The operator can also stop the autoramp at any time by clicking on “STOP”. Clicking “OFF” ramps the HV back to 0.

 

IF AT ANYTIME THE AUTORAMP REPORTS A PROBLEM OR THE CURRENTS ARE NOT EQUAL (TPC ALARM HANDLER), RUN THE VOLTAGE IMMEDIATELY TO 0 AND CALL AN EXPERT!

 

REMEMBER: The cathode HV should not be turned ON until the RHIC beams are stable at collision energy and it should be ramped to ZERO before the beam is dumped.

 

AUTORAMP PROCESSOR

 

The VME program that controls the autoramps for the cathode and anodes is running on a processor (STARGATE) that is located in rack row DC2 in the DAQ room. If the autoramp program stops working it is necessary to reboot this processor. First, try and run the cathode voltage to zero using the GUI for the cathode. Then go to the DAQ room and press the reset button on the STARGATE processor. After it reboots the autoramp should work again.

 

MANUAL MODE

 

The HV can also be set manually as follows:

 

1. Turn on the HV as before.

 

2. Drag the slider switch to the desired HV (this should be done in 10 kV steps max).

 

3. Click on “SET” above the slider bar and the voltage will ramp up. You can stop the ramp by clicking on “STOP” and go back to 0 by clicking on “ZERO”.

 

 

 

 

 

 

 

 

 

 

 

 

4. When the HV stops ramping, check the field cage GUI:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This program is reading the 4 field cage resistor chain currents, the current going to the ground shell (GV current) and the voltage on the next-to-last and last stripes. It also checks that all four resistor chain currents are equal within 100 nA (Delta green lights.)

 

5. After the HV stops ramping, confirm that the currents are equal before ramping further.

 

6. Once the HV is set to the final value, the currents are monitored by the TPC alarm handler. For an alarm, immediately ramp the cathode to zero and call an expert.

 

Typical Field cage currents and voltages at 28.0 kV nominal.

 

OFCW    76.555 µA                                             OFCE     76.553

IFCW     76.547                                                   IFCE      76.552

 

WOFC_0               -33.43 V                                                EOFC_0                                -33.74

WOFC_1               -177.21                                  EOFC_1                                -177.66

WIFC_0                                -23.774                                  EIFC_0                  -23.779

WIFC_1                                -177.58                                  EIFC_1                  -177.47
2.7 ANODE & TRIPS

 

          AUTORAMP

 

To turn the anodes on using the autoramp program:

 

1. Go to desktop # 1 and click on “Anode Voltage” on the top level GUI. This brings up the Anode GUI:

 

 


 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2. Check the ARCNET-BUS status lights for the Inner and Outer sectors – if either or both are red, click  the corresponding “reboot” button.  This will reboot the processor. (The display will go white while it reboots). WAIT ~ five minutes for the reboot. The state of the anode voltages (on or off) is unaffected by rebooting the processor – the Lecroy system has local memory.

 

3. When the status lights have turned green, click on the “Auto-On” button. This gives the GUI:

 

   

 

 

 

 

 

 

 

 

 

 

 

 

If the autoramp GUI displays the message “ARCNET connection lost”, click on the “Reset PGM” button.

 

4. Make sure RHIC has stored, cogged and stable beam!

 

5. At this point, you can go to pedestal voltage (Inner = 700, Outer = 900) or to full operating voltage (Inner = 1170, Outer = 1390).

 

6. To go to pedestal voltage, click “pedestal”. The program will:

 

                Turn on the HV

                Enable all channels

                Ramp HV to 400 volts

                Calibrate the currents (subtract out any DC offset)

                Ramp to pedestal voltage

 

If the HV is already on, the program will just ramp up (or down) to pedestal values.

 

At any time the operator can stop the process by clicking “Abort”. This will ramp the voltage back to 0.

 

After the voltages are at pedestal values, the TPC is ready to take a pedestal run (make sure the GG is on!)

 

7. One can go to full voltage from either the off position or from the pedestal position.

 

From off, the program will repeat the pedestal procedure, and then:

 

                Check for tripped channels

                Check for excessive currents

                Ramp to Inner = 1000, Outer = 1200

                Check for trips

                Check for currents

                Ramp to Inner = 1100, Outer = 1300

                Wait for 2 minutes

                Check for trips and currents

                Ramp to final voltage (Inner = 1170, Outer = 1390)

                Check for trips or currents.

                HV ready for data

 

This procedure takes ~ 10 minutes.

 

If a trip or high current is detected during this procedure , the voltage for all channels will be ramped back to pedestal values automatically.

 

 

To turn the HV off, click on the “Off” button in the auto-on window, or click on the red “Ramp to 0 Volts” button on the main anode GUI.


          MANUAL ANODE OPERATION

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

There are 193  separate anode supplies, 1 for the gain chamber and 192 for the TPC. For each sector, the anode wires are grouped in sections, so there are four supplies per sector. The operator can control the voltage for all sectors (including the gain chamber), for the east or west end only, for a sector only (4 sections) or for an individual section (usually necessary to reset a trip.) In the main GUI above, the status of each power supply (section) is indicated by the round color field surrounding the control button. Thus:

 

                Grey = Channel is disabled. Even if the HV is turned on and you set a demand voltage for that channel, nothing will happen.

                Yellow: Channel is enabled but the HV is off or <10 volts.

                Green: Channel is on at some voltage > 10 volts.

                Red: Channel has tripped off due to excessive current draw. (> 2 mA)

 

NOTE: The Anode program is very slow. You MUST wait for each command to be acknowledged before issuing another command or it will crash!

 

To turn on all sectors manually:

 

1. Check the status lights of the Arcnet-Bus. If either is red, click and drag on the reboot button to reboot the processor. Wait ~ 5 minutes. (There is a separate processor for the inner and outer sectors).

 

NOTE: The ARCNET link is lost frequently – you will get a TPC alarm when this happens. When this link is down the program can’t get updated information from the Lecroy HV mainframe, BUT the HV is still on and the chamber is still protected. Rebooting the processor has no effect on the HV.

 

2. When the ARCNET lights are green, click the HV on button for the inner and outer sectors. Wait for the HV lights to turn green.

 

3. Open the “ALL SECS” control panel:

 

 

 

 

 

 

 

 

 

 

 

 

4. Check that the demand voltage DV (V) for inner and outer reads 0. If not, enter 0, CR in each window.

 

5. Click on “Enabled” for the inner and outer. Wait until the color circles turn green on the main anode GUI.

 

6. Type in a demand voltage of 400 V for the inner and outer sectors. Wait until the voltage ramps up and is confirmed in the readback window.

 

7.Check the Current Calibration status window in the main anode GUI. If the status is “calibrated” continue raising the voltage (see below step 10 ). If the status is uncalibrated, click on the Outer “SHOW I” button in the “ALL SECS” control GUI, drag down to “I (Z > 0) West) and release. This brings up the current display for all the outer sectors on the west end:

 


 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8. Click on the “Calib” button. The status window will say “Current is Ready” and then “Calibration in Progress”. The program will subtract the DC current offsets FOR ALL OUTER SECTORS (east and west). The status window will then say “Calibration Done”.

 

9. Repeat this procedure for the Inner sectors, if needed.

 

10. Set the demand voltage to pedestal values (Inner = 700, Outer = 900). Wait for the voltage to ramp up.

 

 

 

11. Continue to raise the voltage in steps, checking the currents after each step:

 

                Inner = 1000, Outer = 1200

                Inner = 1100, Outer = 1300

                Wait ~ 2 minutes

                Inner = 1170, Outer = 1390

 

12. To turn the Anodes off, either type in 0 for the demand voltage or click on the red “Ramp to 0 Volts” button on the main anode GUI.

 

 

                RESETTING TRIPS

 

Occasionally, one or more channels will draw excessive current (> 2 mA) and automatically trip off. There will be a TPC alarm.  These trips can be random or beam induced. First, STOP the current run. Then,  to reset a tripped channel:

 

1. Click on the individual control button for the tripped channel in the main anode GUI. This brings up the channel status panel:

 

   

 

 

 

 

 

 

 

 

 

 

 

2. Click on the “SET” button. This brings up the control panel:

 

 


 

 

 

 

 

 

 

 

 

 

 

3. In the demand voltage window “DV (V)”, type in 0,cr to set the demand voltage back to zero. Do this FOR ALL tripped channels.

 

4. In the main anode GUI, click on the “Clear Trips” button for inner or outer sectors, depending on which channels tripped. Wait – the tripped channels which were red should turn back to green.

 

 

 

5. If the tripped channel remains grey on the main GUI after 2 minutes, it is neccesary to enable it  manually. Click the “Enabled” button for the channel on the channel control GUI shown in step 1 above. If the channel is not green, you cannot raise the voltage.

 

6. Using the individual channel control windows, slowly raise the voltage in stages back up to the operating point. Monitor the current for each channel. For any indication of excessive current draw, lower that channel back to 0 and call an expert. (Excessive current for constant voltage = 50 nA)

 

7. Record the tripped channels in the “STAR TPC ANODES” binder.

 

NOTE: The current limits can only be changed by the subsystem manager. If a channel will not stay on with a limit of 2 mA, LEAVE IT OFF and call an expert.

 

ALTERNATE METHOD FOR CLEARING MULTPLE TRIPS

 

Sudden RHIC beam losses can cause multple anode trips. A more efficient method for clearing these trips is:

 

1. If the RHIC beam is lost: Use the autoramp to run ALL anode HV down to zero. Then click on the “Clear Trips” buttons. The tripped channels should clear and be ready for the next autoramp.

 

2. If RHIC still has beam and the run will continue then:

 

     First, STOP the current run. Use the autoramp program to run ALL anode HV down to pedestal voltage. Then click on the “Clear Trips” button  for inner and outer, depending on which channels tripped. WAIT for the tripped channels to reset – they should automatically ramp back up to pedestal voltage. You can then autoramp back up to full voltage if the RHIC losses have stopped.

 

2.8 LASER

 

See separate laser manual.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2.9 TPC ALARM HANDLER

 

There is a specific TPC alarm handler which is running on a separate PC – the monitor is located up and to the right of Chaplin. To start the alarm handler, click on the “Shortcut to Alarms_groups” icon on the desktop. The alarm handler monitors the following TPC parameters:

 

               

Anode trips

Excessive Anode currents (any channel)

Cathode HV not  on (must be > 25 kV)

                TPC FEE temperatures < 80 F

                Temperature in the WAH < 82

                Dewpoint in WAH < 62

                Inner and Outer Arcnet links active

                Field cage currents equal

                All gated grid voltages at nominal

                Inner Anode current sum (all channels) < 10 µA

                Outer Anode current sum (all channels) < 4 µA

                Anode HV – check whether any channel is not equal to demand voltage.

 

The alarm handler reads the status of these parameters every few minutes and will sound an audible alarm if something is out of range. There is a 10 minute snooze button that can be used when bringing up the TPC voltages to prevent frequent (false) alarms. If an alarm goes off, it can be silenced (acknowledged) by clicking the button below the alarm.

 

 

The alarm buttons are color coded:

 

                Green = OK

                Yellow = warning but run can continue

                Red = alarm

                Grey  = the data was not read on this try – this usually clears on the next read.

 

An alarm condition will automatically clear and revert back to green on the next read cycle IF the reason for the alarm has been fixed. There is also a “read now” button that will initiate a read cycle.

 

These same parameters plus many others (gas system etc) are also monitored by the slow controls alarm handler running on sc4.starp.bnl.gov.

 


3. ALARMS

 

            3.1 GAS ALARMS

 

In case of a TPC gas alarm:

 

1. Hit the acknowledge button on the alarm box in the control room. This silences the local alarm.

 

2. Go to the gas mixing room – hit the acknowledge button located next to the TPC AB PLC panel in rack 4

 

3. Call an expert – the list is posted in the mixing room.

 

4. The expert will tell you what to do.

 

For a major gas alarm all the TPC HV will trip off automatically. For a minor alarm the HV will stay on and the run can continue.

 

 

                3.2 TPC WATER ALARMS

 

In case of a water alarm:

 

1. . Hit the acknowledge button on the alarm box in the control room. This silences the local alarm

 

2. Go to the gas mixing room – hit the acknowledge button located next to the TPC AB PLC panel in rack 4

 

3. Call a TPC water expert. A water alarm means the skid has shut down (the FEE’s will also trip off).

                This alarm is also repeated to the CAD pump room, so someone may respond from there. Do NOT

                restart the TPC water skid until the problem has been diagnosed and the TPC water expert has

                given the ok.

 


TPC CALL LIST

 

TPC

 

Blair Stringfellow

                Office X7412 (counting house)

                Home  BNL  X1039

                Cell – 631-786-0485

 

Alexei Lebedev

                Office (Ops support trailer)  X3101

                Cell         631-255-4977

                Home  821-2838

 

Jim Thomas

                Office X3918

                Home 928-8661

 

Howard Wieman

                Office X7762

                Home 734-2514

                Cell 631-431-8236

 

TPC WATER

 

Alexei Lebedev

Jim Thomas

Blair Stringfellow

 

TPC GAS

 

Blair Stringfellow

Alexei Lebedev

 

TPC INTERLOCKS                                               

 

Blair Stringfellow

Jim Thomas                                                                                                         

                                                                                                                               

TPC LASER                                                       

Alexei Lebedev

Blair Stringfellow

 

 

 

 

 

 

 

 

 

 

 

5. TPC State Table for Various Conditions

 

 

Standby:                     Anodes off

                                    Cathode off

                                    FEES On

                                    Gated Grid On

 

Pedestal Run:                        Anodes ON at pedestal voltage (or less)

                                    Cathode On/Off (but not ramping)

                                    Gated Grid On

                                    FEEs On

 

Physics Run:              Anodes On at full voltage (Inner = 1170, Outer = 1390)

                                    Cathode on at full voltage (28 kV)

                                    Gated Grid On

                                    FEEs On

 

Laser Run:                 Same as Physics Run but with Lasers On

 

Pulser Run:                Anode off or less than pedestal voltages

                                    Cathode Off/On

                                    Gated Grid On

                                    Fees On

                                    Clock in Local (not RHIC clock)

 

Magnet ramp up or down:

                                    Anodes off or at pedestal

                                    Cathode Off/On

                                    Gated Grid On

                                    FEES OFF

 

Take a laser run 1 hour after the beginning of each store. Take ~ 2000 events and check the drift velocity in the online histograms.

 

Take a pulser run once a day. Make sure clock is set to local oscillator and take a pedestal run first!