Status of the new Target Design n_TOF Collaboration meeting, Paris 4-5 December 2006 P. Cennini AB-ATB Status of the old Target Removal Status of the old

Status of the new Target DesignStatus of the new Target Design

n_TOF Collaboration meeting, Paris 4-5 December 2006

P. Cennini AB-ATB

• Status of the old Target RemovalStatus of the old Target Removal

• New target design New target design

Old Target RemovalOld Target Removal

• Shielding removal: Shielding removal: donedone..• Radioactivity measurement in the Access Pit: Radioactivity measurement in the Access Pit: done.done.• Simulations of the Target Activation: Simulations of the Target Activation: done.done.• Risk Analysis for he Target Removal: Risk Analysis for he Target Removal: done.done.• Procedure for the Target Removal: Procedure for the Target Removal: done.done.• Crane upgrade: Crane upgrade: under discussionunder discussion

Radioactivity MeasurementRadioactivity Measurement

P. Carbonnez SC-RP

Old Target Removal: Actions in ProgressOld Target Removal: Actions in Progress

• Discussion with the suppliers for the construction of a Discussion with the suppliers for the construction of a system certified for radioactive loads:system certified for radioactive loads:expected cost 300 kCHF, expected delivery May 2007.expected cost 300 kCHF, expected delivery May 2007.

• Discussion on the possibility to use the existing crane Discussion on the possibility to use the existing crane after implementations of the infrastructures required for after implementations of the infrastructures required for the recovery of the Target in case of heavy failure the recovery of the Target in case of heavy failure stopping the operation.stopping the operation.

More information on the procedures:More information on the procedures:https://edms.cern.ch/cedar/plsql/cedarw.site_home774982774982 v. v.1 1 n_TOF Target removal and Inspectionn_TOF Target removal and Inspection787079787079 v. v.1 1 Proposal of a Procedure for the recovery of the old Irradiated n_TOF Target in case of jamming of the Proposal of a Procedure for the recovery of the old Irradiated n_TOF Target in case of jamming of the crane.crane.

https://edms.cern.ch/cedar/plsql/cedarw.site_home











Lead Target SimulationsLead Target Simulations

K. Tzolou, V. Vlachoudis ATB-EET



xz-squared target (40x40x55 cm) centerd on the beam axis

55cm

40cm

p beam

Side view Front view

5 cm thick moderator container



xz-squared target (40x40x55 cm) lowered to respect to the beam axis

55cm

40cm

Side view Front view

5 cm thick moderator container

p beam







With varying the thickness of the moderator container, 5 cm seems ideal also for D2O.



• The expected neutron flux with a geometry of 40x40x55cm is the following:The expected neutron flux with a geometry of 40x40x55cm is the following:

Front (center):Front (center): Low energy ~80% NominalLow energy ~80% Nominal High energy >95% NominalHigh energy >95% Nominal

Top (lowest): Top (lowest): Low energy 68x NominalLow energy 68x Nominal High energy 85xNominalHigh energy 85xNominal

The moderator container of 5 cm is the good compromise for HThe moderator container of 5 cm is the good compromise for H22O and DO and D22O.O.

Target Design Specification Target Design Specification

• Target materialTarget material: : leadlead Target cladding:Target cladding: aluminum alloyaluminum alloy Target cooling:Target cooling: water (existing system)water (existing system) Target dimension:Target dimension: ~ 100 liters, ~1.3 tons~ 100 liters, ~1.3 tons Moderation:Moderation: water/heavy water, exchangeable during the runwater/heavy water, exchangeable during the run Useful n-beam diameter at the exit of the target:Useful n-beam diameter at the exit of the target: 40 cm40 cm n-beam losses (versus old configuration):n-beam losses (versus old configuration): 20% at low E, 5% at high E20% at low E, 5% at high E Orthogonal flight-path:Orthogonal flight-path: foreseenforeseen Minimization of the 2.2 MeV Minimization of the 2.2 MeV flash: flash: optimizedoptimized Installation of the new target and moderator exchange:Installation of the new target and moderator exchange: via the shaftvia the shaft Hoist system:Hoist system: same functionality of the existing onesame functionality of the existing one

Target DesignTarget Design

• This Design is based on two principles:This Design is based on two principles:

• Fine positioning of the Target-Moderator assembly made with a new guiding system.Fine positioning of the Target-Moderator assembly made with a new guiding system.(Displacement in the beam direction needed to remove the cooling water after the Moderator ~ 2 cm).(Displacement in the beam direction needed to remove the cooling water after the Moderator ~ 2 cm).

• Replacement of the liquid Moderator made with a “Robot” lifted in place through the Replacement of the liquid Moderator made with a “Robot” lifted in place through the shaft on top of the Target.shaft on top of the Target.

• By using the functionality of the robot, the following goals are achieved:By using the functionality of the robot, the following goals are achieved:

Moderator exchange during the run.Moderator exchange during the run. All the operations remotely controlled from the Service Gallery through the shaft.All the operations remotely controlled from the Service Gallery through the shaft.

The important aspect of this solution is the remote handling of all radioactive or The important aspect of this solution is the remote handling of all radioactive or contaminated elements reducing practically to zero the dose received by the operators to contaminated elements reducing practically to zero the dose received by the operators to exchange the moderator in agreement with theexchange the moderator in agreement with the ALARA ALARA principle. principle.

Documents

Status of the new Target Design n_TOF Collaboration meeting, Paris 4-5 December 2006 P. Cennini AB-ATB Status of the old Target Removal Status of the old