TY - GEN
T1 - Spectrum measurements and calculations in the epithermal neutron beam at the FiR 1 BNCT facility
AU - Seren, Tom
AU - Auterinen, Iiro
AU - Seppälä, Tiina
AU - Kotiluoto, Petri
PY - 2000
Y1 - 2000
N2 - After a period of intense planning, building and
scientific activity by a multi-disciplinary team from VTT
Chemical Technology, Helsinki University, Helsinki
University Central Hospital and the Radiation and Nuclear
Safety Authority (STUK) an epithermal Boron Neutron
Capture Therapy (BNCT) treatment facility for malignant
brain tumours has been established at the FiR 1 TRIGA
Mark H reactor in Espoo, Finland [1]. A crosssection of
the epithermal beam, including the reactor core and the
FLUENTALtm moderator, is shown in Fig. 1.
In the first stage (1996) the thickness of the moderator
was 75 cm. Calculations and measurements with this
configuration showed that the neutron field was of very
good quality with a very small contamination of fast
neutrons [2, 9]. However, in order to increase the
intensity and reduce treatment times the thickness of the
moderator was reduced to 63 cm in the final configuration
(November 1997, shown in Fig. 1), despite a somewhat
higher anticipated fast flux component. The aperture
diameter is adjustable from 8 cm to 20 cm in 3 cm steps
by adding and removing Li-poly plates.
Naturally, the neutron field in the treatment beam must
be characterised as well as possible. An accurate
knowledge of the source neutron spectrum in the BNCT beam
is essential for treatment planning and for in-phantom
calculations and measurements. For that purpose extensive
calculations and measurements have been performed at
several locations, both for a true "free beam"
configuration and with a water phantom at the exit
aperture.
AB - After a period of intense planning, building and
scientific activity by a multi-disciplinary team from VTT
Chemical Technology, Helsinki University, Helsinki
University Central Hospital and the Radiation and Nuclear
Safety Authority (STUK) an epithermal Boron Neutron
Capture Therapy (BNCT) treatment facility for malignant
brain tumours has been established at the FiR 1 TRIGA
Mark H reactor in Espoo, Finland [1]. A crosssection of
the epithermal beam, including the reactor core and the
FLUENTALtm moderator, is shown in Fig. 1.
In the first stage (1996) the thickness of the moderator
was 75 cm. Calculations and measurements with this
configuration showed that the neutron field was of very
good quality with a very small contamination of fast
neutrons [2, 9]. However, in order to increase the
intensity and reduce treatment times the thickness of the
moderator was reduced to 63 cm in the final configuration
(November 1997, shown in Fig. 1), despite a somewhat
higher anticipated fast flux component. The aperture
diameter is adjustable from 8 cm to 20 cm in 3 cm steps
by adding and removing Li-poly plates.
Naturally, the neutron field in the treatment beam must
be characterised as well as possible. An accurate
knowledge of the source neutron spectrum in the BNCT beam
is essential for treatment planning and for in-phantom
calculations and measurements. For that purpose extensive
calculations and measurements have been performed at
several locations, both for a true "free beam"
configuration and with a water phantom at the exit
aperture.
M3 - Conference article in proceedings
SN - 951-38-5273-3
T3 - VTT Symposium
SP - 167
EP - 179
BT - 15th European TRIGA Conference
PB - VTT Technical Research Centre of Finland
CY - Espoo
T2 - 15th European TRIGA Conference
Y2 - 15 June 1998 through 17 June 1998
ER -