Array parameters July 2008 (22/06-02/07)
LABOCA was cold (Helium temperature) between May 11th and July 2nd. No mechanical
work has been performed at the instrument. The bias voltage of amplifier box #3,
which was too low after May 27th, has been adjusted to its nominal value on June
21st. Thus all channel parameters (offsets and gains) were back to the numbers
from May 2008.
The only difference is channel 185, which did not seem to show problems after
mid June. Thus it was no longer considered bad. Otherwise the channel flags are
also identical to May 2008.
Main parameter file: laboca-2008-05.rcp
Notes on individual channels
Channel # | Description |
---|---|
101, 103, 106, 110 | Strong cross-talk: 101↔106 & 103↔110. |
81, 82, 83, 84, 85-96, 135, 136, 142, 145, 150, 151, 157-160 | Channels located in group 4 / cable M. 82 and 84 are considered bad, the other active channels pick up signal from channel 84 (cross-talk). |
6, 180, 184, 204, 220, 228 | Bad channels (no astronomical signal or noisy). |
201, 205, 207, 218, 309 | Insensitive channels. |
179 | This channel shows very low signal and therefore high S/N. |
241 | No proper signal. Picks up signal from channels 248 (strong) and 296 (weak). |
channel_flags-2008-07.boa:
# 25 channels not connected to any bolometer not_connected = [ 29, 33, 35, 40, 64, 66, 124, 135, 142, 144, 146, 151, 158, 189, 193, 195, 200, 224, 226, 284, 295, 302, 304, 306, 311 ] # 20 channels with 1MOhm resistor resistor = [ 15, 16, 87, 88, 95, 139, 143, 145, 149, 150, 157, 178, 181, 186, 187, 188, 190, 255, 310, 317 ] # 2 channels sealed with an absorber blind = [ 4, 163 ] sealed = blind # Channels that show strong cross-talk cross = [ 101, 103, 106, 110, 241 ] # Bad channels (no astronomical signal) bad = [ 6, 82, 84, 179, 180, 184, 201, 204, 205, 207, 218, 220, 228, 309 ] # Remaining bolometers on cable M / group 4 (affected by cross-talk) cable_M = [ 81, 83, 85, 86, 89, 90, 91, 92, 93, 94, 96, 136, 159, 160 ]