East Port Irradiation Facility at LANSCE
East Port Irradiation Facility
This facility provides an intense neutron flux for material irradiation studies and research. Samples can be placed in a small cylindrical container approximately 9-cm diam and 15-cm long that is located in the east Target-4 neutron production target access port. The sample can be placed in the sample holder in a location near the neutron production target. Figure 1 shows a sketch of the location of the East port irradiation cell. The sample cell is located approximately 1.2 m from the neutron production target. The neutron production target presently consists of a tungsten cylinder which is 7.5 cm long and 3 cm in diam surrounded by a thin water cooling jacket. The protons strike the cylinder along the long axis of the cylinder. The vacuum chamber is approximately 2 m in diameter and 1.4 m high. Samples are loaded in the cell at the top of the access port and can be lowered to the irradiation location. The sample cell is shielded with a carbon moderator.
Figure 1. East Port Irradiation Facility.
Because the sample is located close to the neutron production target, it is also exposed to protons and gamma rays that are produced in the production target. Figure 2 shows the calculated neutron, proton and gamma-ray spectrum at the sample position for a proton beam current of 4 microA.
Figure 2 shows the energy spectrum for neutrons, protons and gamma rays at the sample location in the East Port Irradiation Facility.
This facility is mostly used for materials irradiation research because of the time required to access the samples (several hours) and there being no capability for real-time experiment control and monitoring of the samples. The integrated intensity for the various particles are summarized in below Table.
The East Port currently isn't operational. Researchers interested in using this capability should contact the instrument scientist to plan the installation of the experiment and to arrange scheduling.
Integrated Intensity of Particles at East Port
| Particle | Energy Range | Number of particles/cm2/sec (4mA proton current) |
| Neutrons | Above 1.4 meV | 5.74 109 |
| Above 1 eV | 4.59 109 | |
| Above 1 MeV | 4.21 108 | |
| Above 10 MeV | 9.50 107 | |
| Protons | Above 1 MeV | 8.17 105 |
| Above 10 MeV | 7.82 105 | |
| Gammas | Above 0.1 MeV | 1.21 109 |
| Above 1 MeV | 4.1 108 | |
| Above 10 MeV | 6.05 106 |
