Difference between revisions of "Forward Drift Chamber Shift"

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(The Forward Drift Chambers)
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due to the LV applied on the detector pre-amplifieres.
 
due to the LV applied on the detector pre-amplifieres.
 
A cooling system using Fluorinert is used to keep the temperature on the
 
A cooling system using Fluorinert is used to keep the temperature on the
pre-amplifiers below the permissible limit. <font color=red> The LV system should never be turned on if the cooling system doesn't work </font>.  
+
pre-amplifiers within the permissible limits. <font color=red> The LV system should never be turned on if the cooling system doesn't work </font>.  
  
 
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Revision as of 16:02, 2 June 2014

The Forward Drift Chambers

The Forward Drift Chamber (FDC) system consists of four identical packages, each having six chambers (cells). These are planar drift chambers with both wire and cathode strips being readout, in total 12,672 channels.

The cells within a package have independent gas volumes, but are separated with a flexible mylar membrane and therefore the pressure difference between the cells should never exceed 30~Pa .

Positive (up to 2200V) and negative (up to 500V) HV is applied on the sense and field wires respectively with dark currents not exceeding 3 microA per HV channel .

The detector (including cables) emits a total power of about 1500~Watt, of which about 900~Watt inside the magnet, due to the LV applied on the detector pre-amplifieres. A cooling system using Fluorinert is used to keep the temperature on the pre-amplifiers within the permissible limits. The LV system should never be turned on if the cooling system doesn't work .