Users Manual Part 6

IBA | A-6 |
Clinical User’s Guide
Volume 1 - Treatment Session
Nozzle Types and Components
|
PBS Dedicated Nozzle Components
Nozzle Frame
The nozzle frame is the housing used to support and contain all of the nozzle
subsystems accessible from a TR. The nozzle frame has a hollow configuration and
is almost entirely under vacuum.
(Low Pressure) Ionization Chamber No. 1 - (LP)IC1
Ionization Chamber No. 1 (IC1) is the nozzle component where the beam enters the
nozzle. (The Low Pressure Ionization Chamber No. 1 is a model of the IC1).
IC1 consists of a single ionization chamber with the following components:
First single-surface collecting electrode: this electrode is installed along the
path of the beam and is divided into four quadrants surrounding a circular (20
mm diameter) electrode at its center. The whole single-surface collecting
electrode serves as a beam-centering monitor.
Double-surface collecting electrode: this electrode is comprised of the
following:
Upstream face of the double-surface collecting electrode: it is divided into
12 parallel strips used to measure the profile and position of the beam in the
“Y” direction.
Downstream face of the double-surface collecting electrode: it is an integral
collecting electrode that is used to check beam interruption with each
Range Modulator (RM) cycle in Double-scattering mode.
Second single-surface collecting electrode: this electrode is divided into 12
parallel strips used to measure the profile and position of the beam in the “X”
direction.
CAUTION Be aware that the lifetime of Ionization Chambers may be reduced if
exposed to over 10E6 Gray, which corresponds to approximately
450 hours of beam exposure at 5 nA.
Ionization Chamber 1 (IC1) can sustain 450 hours of beam exposure at
5nA.
Ionization Chamber 2/3 (IC 2/3) can sustain 450 hours of unscanned
beam exposure at 5 nA.