PGAA equipment

The PGAA instrument is located near the end position of the neutron guide No. 1. The upgraded 2Qc supermirror neutron guide improved the thermal-equivalent neutron flux at the PGAA sample positions to 9.6x10 ⁷cm^-2 s^-1. The beam can be collimated to a maximum cross-section of 2x2 cm². Other cross-sections of 14x14 mm², 10x10 mm², 42 mm², 23 mm², 5 mm² can be adjusted. Furthermore, a 1/30 attenuator can be applied to reduce the beam intensity, if necessary. A pneumatically actuated instrument shutter is used to control the entry of the neutron beam into the cabin while two computer-controlled secondary shutters are in place to allow independent operation of the PGAA and NIPS/NORMA facilities. The targets are mounted on thin Al frames by Teflon strings. The detector system of the PGAA facility consists of an n-type high-purity germanium (Canberra HPGe 2720/S) main detector with closed-end coaxial geometry, and a BGO Compton-suppressor surrounded by a 10 cm thick lead shielding. Variable lead gamma collimators with slits of 30 mm diameter, 2x20 mm² or 5x5 mm² are available for PGAI measurements. A digital signal processor combined with an Ethernet-based multichannel analyzer module (Canberra AIM 556B) collects the counts. A user-friendly facility control program is used for manual, semiautomatic, and unattended automatic batch measurements. The possibility to apply complementary techniques are recommended to consider. The internal agreement of Centre for Energy Research and Wigner Research Centre for Physics allows a unique opportunity for applicants for PGAA studies to perform non-destructive analyses by external milli-beam PIXE (Particle Induced X-ray Emission) measurements on their HS objects within the same TNA mission on the same campus. These measurements at Wigner 5 MV Van de Graaff accelerator provide complementing near-surface elemental concentration values on selected spots of mm size. Differing sensitivity characteristics of these techniques can also complete each other. The number of available PIXE working days is limited to 13 days in the whole IPERION HS project. Request for this possibility should be indicated in the application to the PGAA technique.