Upgrade of the prompt gamma activation analysis and the neutron-induced prompt gamma spectroscopy facilities at the Budapest research reactor La ´szlo ´ Szentmiklo ´si • Tama ´s Belgya • Zsolt Re ´vay • Zolta ´n Kis Received: 26 July 2010 / Published online: 29 August 2010 Ó Akade ´miai Kiado ´, Budapest, Hungary 2010 Abstract The Budapest Research Reactor’s Prompt Gamma Activation Analysis (PGAA) and Neutron-Induced Prompt gamma Spectroscopy (NIPS) facilities were sig- nificantly upgraded during the last few years. The higher neutron flux, achieved by the partial replacement and realignment of the neutron guides, made feasible the automation and specialization of the two experimental stations. A new neutron flux monitor, computer-controlled beam shutters and a low-level counting chamber have been put into operation to assist with in-beam activation exper- iments. An automatic sample changer has been installed at the PGAA station, while the NIPS station was redesigned and upgraded with a Compton suppressor to use for the non-destructive analysis of bulky samples. In the near future the latter setup will be completed with a neutron tomograph and a moving table, to turn it into a Neutron Radiography/Tomography-driven PGAA equipment. Keywords Prompt gamma activation analysis Á Neutron- induced prompt gamma spectroscopy Á Low-level counting chamber Á Sample changer Á Neutron monitor Á In-beam activation Introduction Since starting its operation in 1996, several major upgrades were accomplished at the Budapest prompt c facility in order to improve its performance and productivity. This is in line with the trends at other prompt gamma activation analysis (PGAA) facilities [1–3]. From 1996 to 2000 a thermal neu- tron beam was available at the Budapest Research Reactor with a flux of about 2 9 10 6 cm -2 s -1 [4, 5]. Following the installation of the cold neutron source at one of the reactor’s tangential channels [6] in 2000 and the modifications made in the neutron guide system, the beam flux increased sub- stantially to 3 9 10 7 cm -2 s -1 . At the end of the neutron guide the rectangular beam was split into two square sub- beams to serve two independent experimental stations. The PGAA facility was dedicated to chemical analysis; while the neutron-induced prompt gamma ray spectroscopy (NIPS) facility was used for advanced nuclear spectroscopic mea- surements, including c-c coincidence studies [7]. This con- figuration was operational between 2001 and 2006. The most important feature of that system was the exceptionally low beam-background [8], which provided ideal conditions to establish a library of radiative neutron capture gamma-rays for chemical analysis [9]. In 2003 a beam-chopper was added to the PGAA setup for studies on short-lived radionuclides [10–12] produced during the irradiation. The last significant upgrade started in 2007, when the last section of the neutron guide no. 1 was changed to 2h c supermirror elements [13], increasing the thermal equiva- lent neutron flux to 1.2 9 10 8 cm - 2s -1 at the PGAA and 7 9 10 7 cm -2 s -1 at the NIPS sample positions, respec- tively. A new 27% relative efficiency HPGe detector with an elongated crystal was purchased that fit into the existing PGAA Compton suppressor. New components of the data acquisition electronics were also put into operation. A factor of 20–50 gain in the neutron flux, compared to the performance of the original thermal system, made it pos- sible to significantly reduce the beam time needed to measure a sample. It was soon realized that a more efficient way of oper- ation under these new conditions requires a higher level of L. Szentmiklo ´si (&) Á T. Belgya Á Z. Re ´vay Á Z. Kis Institute of Isotopes, Hungarian Academy of Sciences, P.O. Box 77, Budapest 1525, Hungary e-mail: szentm@iki.kfki.hu 123 J Radioanal Nucl Chem (2010) 286:501–505 DOI 10.1007/s10967-010-0765-4