MIKE STRANG
Thu, 28 Jun 2001

The HV controls have settled into the final configuration. The HV Control
Sheet in the FPD CR has been changed to reflect this.

The biggest change is that you now use:

setup -t onl_apps
/online/config/fpd/hv/fpd.hv &

to turn on the HV control program. When it is turned on, you will see a
sheet with two tabs. One tab is labeled L0 and the other is labeled MAPMT.
You can choose the tab that reflects which tubes you are going to turn on.
It is very important to NEVER turn on the MAPMTs unless you have verified
the corresponding rates at the L0 tube.

Also, for now never turn on the tubes above 90% unless we are testing the
tubes.

Attached is the control sheet that is also in the control room.

<a href="http://www-d0.fnal.gov/fpd/FPD_News/Standalone HV Control.doc">
http://www-d0.fnal.gov/fpd/FPD_News/Standalone HV Control.doc</a>.

################
Sun, 08 Jul 2001

Here are the access plans with (hopefully) the last modifications.

Collision Hall
--------------

Replace patch panel near PW08 (1 hr, Michael Strang):

    Take patch panel and signal generator into collision hall along
    with plug map (remember A1I is A1D). Plug ribbon cable into flat
    cable and send signal through BNC connector and verify that it is
    received in the SCR. If everything works, plug in L0 cables from
    tunnel into correct BNC location.

Tunnel (in order of importance)
-------------------------------

Before entering the tunnel, those going into the tunnel and those
remaining in the control room need to read the HV safety
documentation. A note must be placed at the computer in the SCR to
not turn on HV to any castle unless notified by those in the tunnel.
Copies of the HV safety documentation will be taken down into the
tunnel and placed near each castle.

Items needed before access:

    We need to secure the Gauss Meters (Prep? D0?), find which cables
    can carry the signals, and get the 16x2 pin extenders. We need to
    take screw driver, multi-meter (to test HV splitter integrity),
    tape to mark cables, marker. Need to make copies of the HV safety
    instructions.

Also, all L0 HV cables will be marked with tape to distinguish from
MAPMT HV cables. Whenever a pot is connected to the HV and signals
it must be verified by at least two people.

If HV is to be turned on for a test, no other work can be performed on
other castles until the HV has once again been disabled.

Fix P2U (30 min if simple, 3 hrs min if complicated, Mike S. et al):

    See which HV cable is plugged into the PMTs at P2U. If it is
    wrong, put the correct cable. If the correct cable is connected,
    the cartridge top will need to be opened to verify the HV splitter
    is intact. If there is a problem with the HV splitter, the
    cartridge top will need to be removed from the tunnel so that it
    can be repaired. If the HV splitter is intact then verify
    connections at the amplifier. If everything looks ok, I'm not
    sure what else can be done.

    Using 16x2 pin extender (I still don't know what it is called),
    add these to the new pin tubes to help increase the connectivity
    between signal cables and tubes.

    Once the cartridge top is reconnected, an initial test is to turn
    on the MAPMT HV and verify that current is being drawn by the
    tubes. Then the LMB can be used to strobe the MAPMTs to verify
    connections.

Fix P1U (30 min if simple, 3 hours min if complicated, Mike S. et al):

    Only fix P1U if P2U has been fixed and tested.

    Open cartridge top and use 16x2 extender to make better signal to
    cable connections. Look at tube 5 to see if reason for no signals
    can be determined. If HV cable has come loose, reattach if able
    If pin is broken, cartridge top will need to be removed from the
    tunnel for repairs. If HV is connected properly verify connection
    cables at the amplifier.

    Once the cartridge top is reconnected, an initial test is to turn
    on the MAPMT HV and verify that current is being drawn by the
    tubes. Then the LMB can be used to strobe the MAPMTs to verify
    connections.

Measure Magnetic Field (1-2 hours, Mike S et al.):

    Verify which cables in the tunnel can carry signal from a Gauss
    Meter to the SCR. Position meters near castles and connect to
    proper cables. Take a magnet of known strength and test that the
    signal received in the SCR is of the expected value. We will take
    measurements over the next few stores to get a feeling for the
    field.

    We can also get an idea of the effect by measuring the MAPMT
    signal using the LMB both with and without magnetic field. The
    field signal can be measured at any time there is beam. The
    without field signal can be measured during the access or whenever
    there is dead time.

Clear Camera View (30 Min, Mike S. et al):

    Move some cables so the camera has a clear view of the motors.
Verify with the SCR that the view is cleared. Use a marker to put
    markings on the motors to make it clear when they are moving.

Test new 5V circuit (4 hrs?, Lionel et al):

    Reconfigure two castles to use the new 5V circuit and verify pot
    motion.

Replace RM at dipoles (2 hrs, Lionel et al):

    Place RM at dipole location and verify that the dipoles can be
    moved using the software.

Calibrate LVDTs (1 hr, Lionel et al):

    From the SCR move the castles through the entire range of motion
    to properly calibrate the LVDTs and the values that they pass in
    to ACNET

################
Fri, 13 Jul 2001

We seem to be making some progress in the CAMAC to VME rundaq program.
Lionel is also working on the new version of the pot motion software.

We have reinstalled the RMI at the dipoles and they will be activated
for the next time we have beam.

We have moved the in and out pots manually to make sure they are not
stuck.

We are able to see LMB signal from P1U but the new HV scheme appears to
have introduced some additional noise at the ~20mV level. Pierrick and I
will investigate this tomorrow.

P2U will not accept voltage above 400V. I went into the tunnel and
plugged P2I into the HV so that I was using a different Slot and Channel
from the HV crate and observed the same problem. We pulled the pot from
the tunnel but could not see anything obviously wrong. There were a few
places that weren't shrink-wrapped like P1 so we wrapped them in
electrical tape and will test again tomorrow morning. We swapped tube #4
(channels 8-16 are noisy even though the connection at the tube appears
good) to slot #2 (mixed plane) so that the problem would have minimal
impact.

We installed the Gaussmeter at P1 using the L0 P1I cable to carry the
signal out. While in the tunnel, carlos moved the meter around various
places and was getting a few gauss even with the magnet off. This
appeared to be perpendicular fields to the tubes however.

So, tomorrow we will keep working on P1U and P2U. If we can't get the
problem solved with P2U we will go back to the old way of soldering
everything together since it has been shown to work so that we can
design something better to split the voltages. All of the tubes have
been moved and there are no more spares we shouldn't have to swap any
more tubes until October anyway.

We will also try to find available machines to modify the cartridge top
for one pseudo-detector to accept the "official" L0 PMT magnetic shield.
If we can't access the equipment we will then wrap one tube with
multiple layers of the mu-metal foil (this will be A1U whichever
solution.) We will then wrap A2U L0 tube with a single thickness of
mu-metal foil and we will wrap P1U with what is left (at least 1
thickness, probably more).

################
Sun, 15 Jul 2001

Today we just verified everything in the tunnel. We used a pulser at
each L0 signal cable and verified that it arrived in the tunnel. We
verified that all L0 tubes draw current and recorded the current being
drawn for each location at -1800V. We observed that A1 appears to draw
about 0.4 mA more current than all other locations and that when the
tubes are first turned on, the current shoots past the steady state
valued and takes about a minute to settle to the steady current. We also
recorded the current being drawn by the MAPMTs at both positions
at -900V.

We installed plane mirrors at P1 and A1 that allow us to vaguely see the
down motor. We will have to wait until we try to move the pots to see if
it actually works. We will most likely not be able to keep the mirrors
in the current locations once we install the in and out pots. We were
unable to effective used the convex mirror and were unable to see the
racks. In order to do something like this, and to better focus on the
mirrors we need to optimize the positions of the cameras in the October
shutdown.

Lionel said that the new pot motion software is working good and Victor
is continuing to work on the VME DAQ and making good progress.

Carlos is going to gather data from the MAPMTs in no magnet conditions
and we will record the data about the PW08 rack tomorrow morning before
they close the collision hall.