Beam Quality

Our T-105, T-160, T-200 and T-300 systems ensure absolutely reproducible parameters when applying different beam qualities.

Half-value Layer Thickness
The T-105, T-160, T-200 and T-300 systems allow half-value layer thicknesses to be shown for the full range of conventional radiotherapy. Seven automatically selectable filters can be combined with the parameters tube voltage [kV] and tube current [mA] into up to 20 selectable beam qualities.

Typical half-value layer thicknesses of energies used, as generated by our systems:

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Timeout
When the tube voltage is switched on, there is a start-up characteristic that affects the constancy of the dose rate for short treatment times. Older systems sometimes need several seconds to reach the nominal tube voltage. With such significant switch-on effects it may become necessary to switch the entire treatment dose using the ionisation chamber, to compensate for this time error.

Time error = (T2 x R1 – T1 x R2) / (R2 – R1)
where R2, R1 are dose readings for time settings of T2 and T1, respectively

The controls of our T-105, T-160, T-200 and T-300 systems adjust the parameters tube voltage [kV] and tube current [mA] to their nominal values within one second, with a nearly rectangular signal image. This virtually eliminates the time error.

The T-105, T-160, T-200 and T-300 radiotherapy systems are able to switch the planned dose by timer, precisely and reproducibly, even for short treatment times.

A second identical timer monitors the function of treatment time and reliably switches off the radiation in the event of a fault.