A Channel is the combination of the Transfer Tube and the Source Applicator. A Channel is physically connected to one of the connection sockets of the afterloader. Afterloader Channel ID (300A,0273) unambiguously identifies the afterloader channel to which the applicator is connected; see Section C.8.8.15.16.2. Both Afterloader Channel ID (300A,0273) and Source Applicator ID (300A,0291) describe the connection between the afterloader and the applicator (so called channel mapping). Channel Number (300A,0282) is used to index the Items within the Channel Sequence (300A,0280) and does not serve as the identification of the channel socket at the afterloader.
Note
Channel Length (300A,0284) has been interpreted in different ways. Channel Effective Length (300A,0271) should be used instead, as the distance from the afterloader to the center of the distal-most possible dwell position following the definition in Figure C.8.8.15-1.
Additionally, the Transfer Tube Length (300A,02A4) may be specified. If Transfer Tube Length (300A,02A4) is absent or has no value, the distance from the Source Applicator connector to the center of the distal-most possible dwell position is equal to the value of the Channel Effective Length (300A,0271). If Transfer Tube Length (300A,02A4) has a value, the distance from the Source Applicator connector to the center of the distal-most possible dwell position is equal to the Channel Effective Length (300A,0271) minus the Transfer Tube Length (300A,02A4). The concept of Source Applicator Length (300A,0296) should not be used any longer.
