1/5/2005

# 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]{.underline}**

**[1.1 FEE's (Front End Electronics)]{.underline}**

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]{.underline} 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]{.underline}**

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]{.underline}**

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]{.underline}**

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]{.underline}**

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:]{.underline}**

**[2.1 Boot & setup of Control Computer]{.underline}**

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)

![](media/image1.png){width="3.7493055555555554in"
height="2.8256944444444443in"}

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]{.underline}**

All TPC functions are controlled using VME CPU's which are located in
VME crates on the 2^nd^ 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 "2^nd^ floor VME". This will bring
up the VME control GUI:

![](media/image2.png){width="4.875in" height="2.3534722222222224in"}

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:

![](media/image3.png){width="4.388194444444444in"
height="3.647222222222222in"}

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:]{.underline}**

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 Crate 52 Rack 2A7

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 -- BURTON processor in DAQ
room rack DC2 (push reset)

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]{.underline}**

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:

![](media/image4.png){width="6.396527777777778in"
height="4.694444444444445in"}

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]{.underline}**

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:

![](media/image5.png){width="5.070138888888889in"
height="4.241666666666666in"}

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
8^th^ 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]{.underline}**

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:

![](media/image6.png){width="4.708333333333333in" height="2.46875in"}

1\. Click on the "Default Sequences" button. This brings up the control
screen:

![](media/image7.png){width="2.4993055555555554in"
height="1.4152777777777779in"}

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:

![](media/image8.png){width="4.43125in" height="2.3229166666666665in"}

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:

![](media/image9.png){width="4.665277777777778in"
height="1.4472222222222222in"}

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]{.underline}**

### 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:

![](media/image10.png){width="5.030555555555556in"
height="3.7708333333333335in"}

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:

![](media/image11.png){width="2.323611111111111in"
height="2.4611111111111112in"}

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 turned OFF before the
beam is dumped.

**[AUTORAMP PROCESSOR]{.underline}**

The VME program that controls the autoramps for the cathode and anodes
is running on a processor (BURTON) 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 BURTON 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:

![](media/image12.png){width="4.75in" height="4.036111111111111in"}

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]{.underline}**

**[AUTORAMP]{.underline}**

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:

![](media/image13.png){width="6.977083333333334in"
height="4.502083333333333in"}

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:

![](media/image14.png){width="2.1277777777777778in"
height="2.2527777777777778in"}

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]{.underline}**

![](media/image13.png){width="6.241666666666666in"
height="4.027777777777778in"}

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 μA)

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:

![](media/image15.png){width="4.625in" height="1.4548611111111112in"}

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:

![](media/image16.png){width="4.124305555555556in"
height="2.482638888888889in"}

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]{.underline}**

Occasionally, one or more channels will draw excessive current (\> 2 μA)
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:

![](media/image17.png){width="2.9902777777777776in"
height="1.5743055555555556in"}

2\. Click on the "SET" button. This brings up the control panel:

![](media/image18.png){width="1.8743055555555554in"
height="1.5368055555555555in"}

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\. 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)

6\. 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 μA, LEAVE IT OFF and
call an expert.

**[ALTERNATE METHOD FOR CLEARING MULTPLE TRIPS]{.underline}**

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]{.underline}**

See separate laser manual.

**[2.9 TPC ALARM HANDLER]{.underline}**

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]{.underline}**

**[3.1 GAS ALARMS]{.underline}**

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]{.underline}**

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]{.underline}**

**[TPC]{.underline}**

Blair Stringfellow

Office X7412 (counting house)

Home BNL Apt 24B X1047

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]{.underline}**

Alexei Lebedev

Jim Thomas

Blair Stringfellow

**[TPC GAS]{.underline}**

Blair Stringfellow

Alexei Lebedev

**[TPC INTERLOCKS]{.underline}**

Blair Stringfellow

Jim Thomas

**[TPC LASER]{.underline}**

Alexei Lebedev

Blair Stringfellow

**[5. TPC State Table for Various Conditions]{.underline}**

**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!**