Large Wire Chambers Or To boldly go where nobody has gone before Frame chambers (say up to 5x5 meters) usually made on winding machines Cylindrical chambers (ala CDF say) done by stinging in situ, but situ here is usually a clean lab followed by a truck ride to the expt location Some other large chambers made by individual wire stringing. Large liquid argon wire chambers not calorimeters- we have only one example, ICARUS. In addition the quasi-example of LANDD Petros Rapidis, Fermilab The ICARUS experience A floating construction to avoid distortions Note the scale vs the atrium of the high rise! Also note the ice-cream parlor quality of this operation ! LANDD not of much help a frame chamber probably built ahead of time For transparency: E n+1 =1.5 E n With E drift = 0.5 kV/cm, 7 wire planes: - 2 grid planes + 1 screen plane made by vertical wires referred to ground - 2 induction planes with horizontal wires biased at V - 2 collection planes with vertical wires biased at +675 V Stainless steel wires with 100 m at a 3 mm pitch. Channel maximum capacitance in LAr: 23 pF/m 40 m + 2 m Cable 1 nF ENC 1600 e - RMS, S/N 8-10 for minimum signals WHY? WIRE MATERIAL AISI 302 Stainless Steel, 4/4 hard drawn, polished Max. Load R m = 2350 Nmm -2 Elastic Limit R p0.2 = 2100 N mm -2 sag L 2, cos ( ) For 150 micron wire 30 m long 27 mm elongation due to tension at 2.1 kgf 9 mm due to temperature excursion Use sketch here =8.854 e-12 F/m C=F/m=14 pF/m = 14 e-12 F/m L =30m S=5mm=5 e-3 m V=500Volts T in newtons But 500 may be too large, is larger for argon, L is more like 5 meters so it is OK Stability of grid plane Are microphonics an issue here ? Lots of room for weights and pulleys Also a similar structure buried in the side pillars A Frame approach A top truss and side walls we need more information from CBI also about doors, cranes, holes, discarded BLT sandwiches How large chambers can you string??? WH 15 floorWH 6 floor String(ing) Sextet: L. Bartoszek, B. Fleming, H. Jostlein (in absentia), K.Kephart, A. Para, P. Rapidis 5 wires, ~25 m long, 4 mm spacing But enjoyable as this was this is not the way to go Techniques have to be developed e.g. a wire stringing machine(s) ? All of this in an environment of cleanliness And one has to also think about auxiliary instrumentation (thermometers, motion transducers, stirrers, bubblers,) And Also auxiliary systems (e.g. a survey system inside the tank). Do we need a long prototype 30m long ? 10% cylindrical (astigmatic) distortion Rule of thumb local distortions up to say 5% of pitch are probably acceptable, and global distortions that do not violate the above rule (but are uniform) are also acceptable The End