Runplan for oct23/04

*** The purpose of these studies is to try to find a suitable tune:
***   2000Hz trigger rate of 29.6MeV/c surface muons
***   Horizontal focus at F1
***   Horizontal and vertical focus at F2
***   Horizontal and vertical focus at F3 = -134cm
***   sigma of x < 12mm, sigma of y < 5mm
***   sigma of angle in x < 10mrad, sigma of angle in y < 20 mrad
***   mean x,y within 2mm of zero, mean angle in x,y < 5mrad 

Note: to scale the momentum of the channel see the instructions in
below in item 5) the surface edge scan.

1) Finish the F1HP scan started by Ryan -- then consult with experts?  Consult
elogs on Oct21-22 for procedure.  These are short runs to look at the mean
position and angle in x.

2) With 40MeV/c with pions and slits set for nominal tune (see ubeam printout 
taped to monitor), try to get a measure of how much Quad steering we have.  
To do this we will see how much shift in <x> and <y>  there is when we 
turn off all of the quarupoles.  To do this take a nominal run as determined 
and record <x>, sigmax,<y>,sigmy,<ax>,sigmax,<ay>,sigmay, and the ratio 
of B1NMR/B2NMR.  Then turn off just Q6 and Q7, then take a run and record all of 
the same values.  Now adjust B2 to center <x>=0 in the TEC.  Take another run with 
this setting of B2, and record all the same values.  Now turn off the rest of 
the quads, take a run and record all the same values.  Again readjust B2
to center <x>=0, take a run, recenter... The record above will give 
us some idea of how much quad steering there is.  With quads on you can get 
about 50,000-100,000 events, with quads off <10,000 events should do since the rate 
will be much lower.  Note that you get mean x, y from the TEC histograms made
in a postcript file when you run the analysis.  See the Zeroth order TEC 
instructions linked from the current run page for analysis instructions for TEC.

Note for the next step, that when changing beam momentum you will need to adjust 
the ADC vs TCAP cut to select the particles you want to look at when doing the TEC 
analysis.  This is done by editing ~twistonl/TestTEC/run/tec.kcm (see the 
Zeroth order TEC instructions).

2) I think we have given up on finding our lost beam rate.  Now we need to open 
F0VW and F0VH to make the M rate about 2000Hz.  To figure out what setting we 
will need, load the 29.6MeV/c tune with all nominal settings (as is on the sheet
of paper on the right monitor of midtwist).  Open F2H Slit wide enough to get all 
of the beam.  Then take a run for each of these settings, all with centered 
positons:
a. (F0VW=12mm,F0HW=40mm) B2 adjusted to center <x>=0 in TEC
b. (F0VW=18mm,F0HW=60mm) B2 adjusted to center <x>=0 in TEC
c. (F0VW=24mm,F0HW=80mm) B2 adjusted to center <x>=0 in TEC
d. (F0VW=36mm,F0HW=120mm) B2 adjusted to center <x>=0 in TEC
e. (F0VW=49mm,F0HW=150mm) B2 adjusted to center <x>=0 in TEC
For each setting record the visual scaler rate, and total scalers for the run of 
M and T1ION and the ratio of M/T1ION.  The visual scalers can be read from the
rack through the window to the other room of the counting room.  The totals
can be obtained when the run is stopped by logging in as twistonl, then:
 cd /home/twistonl/TestTEC/run
 source start_tec
 source GetScaler.csh runnumber
where for runnumber you enter the number you want to get scalers for. I suspect
that setting b. will become nominal a. will be low rate and c. will be high
rate.  For each setting 100,000 events is sufficient.  Note that FOVW is short hand
for the F0 vertical jaw width, and F0HW is short hand for the F0 horizontal
slit width.  For more description of the beam line see the M13 and epics instructions
linked from the current run page.

Once we have the nominal settings of F0VW,F0HW ...

4) Now we want to move the horizontal focus and waist to be at z=-134cm. To do
this we will try to find trade off between minimum beam size sigmax,sigmay and 
minimum divergence <ax>, <ay> at z=-134cm (so record those values for each 
setting we try).  Our method for moving the focus is to adjust the quadurpoles 
Q6 and Q7 which are after the last bending magnet.  So load the 29.6MeV/c tune. 
Set F0VW, and F0HW set the the widths determined in 1), and B2 adjusted to 
centered.  Again we will leave F2HSlit wide enough (as determined in 1) to 
get all of the beam through that aperature.  Take runs with each of the 
following settings of (Q6,Q7):
nominal=(440,493), 
+5%=(462,517), +10%=(484,542), +15%=(506,567), +20%=(528,592)
-5%=(418,468), -10%=(396,444), -15%=(374,419), -20%=(352,394)
It would be particularly interesting if we can find a setting that reduces
the beam angle in y (<ay>) since it is too large at the nominal setting.  This 
may be possible by trying a few settings steering Q6 at fixed Q7, then Q7 at 
fixed Q6.

...

Now with the 29.6MeV/c tune, and settings of F0HW, F00VW determined in 1), 
and the settings of Q6,Q7 as determined in 4), and keeping F2HW wide enough
to see all of the beam proceed with 5).

5) Perform a momentum edge scan to see where we are relative to the surface
muon edge.  For each momentum of the edge scan take about 100,000 events of 
TEC data, and record M, T1ION rates from the visual scalers. Record
integrated rates over a run using the GetScaler.csh described in 1). Also
record the B1DAC and B1NMR setting.  To do the edge scan try the following 
beam momenta: 25, 26, 27, 27.5, 28, 28.5, 29, 29.5, 29.6, 29.65, 29.7, 
29.75, 29.8, 29.85, 29.9, 29.95, 30.0, 30.1, 30.5, 32.0,32.8,33,34,35MeV/c

To change the beam momentum, use EPICS.  Start with the nominal beamtune for
29.6MeV/c muons.  To get the nominal tune follow the instructions here:
http://twist.triumf.ca/private/online/run_instructions/epics_instructions.html
You can use the scale feature of EPICS to go from 29.6MeV/c to another 
momentum. This is found on the TWIST Save/Restore panel, where different 
beam tune files are also loaded from.  The bottom half of this panel is used
to scale the beam momentum.  On the left side change the P2 value under new to 
the value you want to scale to.  Then to the right of the correct functions, 
click on the calculate button.  Once it finishes calculating, under Apply, 
press the scale button for each of the dipoles (B1&B2).  The new values to try
to bring the B1 and B2 NMRs to is then the second and fourth lines to the left
of the comments (on the lower right).  You then need to try to get the NMRs
locked to see if the value matches what EPICS says you should get.  If they do
not match (probably the case), you need to adjust the coarse B1 and B2 DAC 
values until the NMR is set to the right value.

For the analysis see the zeroth order TEC instructions.  You will need to 
adjust the ADC vs TCAP cut at each new momentum to select the muons.