G_L = G_0 * ------------ = 149 +/- 3 V/(m/s)
R_x + R_c
G_0 = 340 V/(m/s) (generator constant)
R_x = 4300 Ohms (external damping resistor in Pomona box)
R_c = 5500 Ohms (internal coil resistance)
m * x = (x_G - x) * k + d(x_G - x) * b
x w0^2 + i*w*w0/Q
---- = -----------------------
x_G w0^2 + i*w*w0/Q - w^2
d (x - x_G) ( w0^2 + i*w*w0/Q ) . w^2 .
dt = ( ----------------------- - 1 ) * x_G = ----------------------- * x_G
( w0^2 + i*w*w0/Q - w^2 ) w0^2 + i*w*w0/Q - w^2
gain = 10
Since we reduced the integration time of the particle counter by a factor of 10, we had to add a gain of 10
to the EPICS channels C1:PEM-count_full and C1:PEM-count_half.
I asked Alex to change it and he did it. I forgot to ask him to change the gain of C1:PEM-count_half. So now only
C1:PEM-count_full has x10 gain.
C1:PEM-count_full and C1:PEM-count_half are 'Soft Channel' records in the database (Pcount.db). The values are actually
written into the VAL fields directly by an SNL code Particle.o.
Particle.o reads data from the RS-232C port, to which the particle counter is connected. Then it parses the data and put values
into relevant EPICS channels using channel access. This means we cannot change the gain of the channels by modifying the
database file. For example, ASLO field does not have any effect when the value is directly written into the VAL field.
We had to modify the SNL code. Alex modified Particle.st and the new SNL object file is Particle_x10.o sitting in
/cvs/cds/caltech/target/c1psl/. I modified seq.load so that c1psl loads Particle_x10.o when rebooted.
The source code for the old Particle.st can be found on lesath.ligo.caltech.edu in
I asked Alex to disclose the location of the source of the new code.
In order to compile the SNL code into an object file for Motorola CPU by ourselves, we have to call Dave Barker at LHO.
At the request of Steve, I modified the HIGH value of C1:PSL-FSS_RMTEMP from 21.27 to 23.0.
The HIHI is set to 23.50.
noise in m/s = -------------------
10 * 802(V/(m/s))
G = 1e-9
p = 0, 0
z = 0.7 0.7
i.e. ------ ~ f
Quick update on my wiener filtering status:
Joe has been helping me get on the GRID, so I now have a grid certificate, and accounts on most/all of the clusters.
Joe also helped me get menkar to get S5 data so that I can do wiener filtering to the back-data.
I've been running the wiener filtering algorithm, and right now, it doesn't do anything to improve the DARM_CTRL data. I am confident that this is because something is funky in the wiener filtering algorithm somewhere. The indicator of this is that the wiener filtering calculation takes the same amount of time (~95 seconds) to calculate a filter for 64 seconds of data as for 1 hour of data (both for N = 2000 taps).
For reference, attached are my plots for the wiener filtering result for (1) 64 seconds of S5 data, and for (2) 3600 seconds of S5 data.
These plots were made using H1:DARM_CTRL as the signal to minimize, with 4 seismometers as the witness channels (EX_SEISX, EY_SEISY, LVEA_SEISX, LVEA_SEISY)
I'm working on figuring out what's going on with the filtering algorithm, and why it does work for C1:MC_L minimization, but does not work for H1:DARM_CTRL minimization.
The outside particle counts for 0.5 micron are 3 million this morning at 9am. Low clouds, foggy condition with low inversion layer.
This makes the 40m lab 30-50K
I just turned on the HEPA filter at the PSL enclosure.
Please, leave it on high
The Caltech gasoline storage tank is being upgraded.
They are jack hammering and digging with bulldozer 50 yards south of ETMY