Speaker
Description
The advent of high-efficiency gamma ray spectrometers with multiple
types of detectors, digital-signal-processing based data acquisition system, and
the realistic possibility of taking a stride in the hitherto unknown territory of nuclear
landscape are driving the low- and medium-energy nuclear physics into the path of
exciting exploration. With this in consideration, a novel facility, DURGA (Dhruva
Utilization in Research using Gamma Array), has recently been developed at
Dhruva reactor (R3001 neutron beam-port), by the Nuclear Physics Division
(NPD), Bhabha Atomic Research Centre (BARC), Mumbai, India. The concept and
possible utilization of the aforesaid facility is very unique in the sense that it is the
only other such large-scale experimental facility in the world, apart from the FIPPS
at Grenoble, France, for carrying out “prompt” γ-ray multi-fold coincidence
spectroscopy using thermal-neutron beam. The hybrid gamma-detector array in
the facility, consisting of eight Compton-suppressed clover Germanium detectors
(32 HPGe segments) and ten LaBr3(Ce) fast scintillators in its present
configuration, is integrated with an in-house developed, state-of-the-art
multi-frequency digitizers-based trigger-less data acquisition system for high data
throughput. With this facility, rich Physics in the realm of neutron-rich radioactive
nuclei as well as low-excitation energy regime of stable nuclei, that have been
hitherto inaccessible through the existing nuclear structure research facilities in
India, can be explored. Apart from Prompt Capture Gamma Spectroscopy (PCGS)
and Prompt Fission Fragment Spectroscopy (PFFS), Decay-Gamma Coincidence
Spectroscopy (DGCS), at times even in combination with the Pneumatic Carrier
Facility (PCF) at Dhruva, has also been one of the major research activities at this
facility. This digital hybrid gamma detector array, when used in combination with
the Pneumatic Carrier Facility (PCF), poses as one of the most powerful setups for
half-life measurements and decay spectroscopy. Nuclei with higher
neutron-to-proton ratios are difficult to study in accelerator-based facilities using
stable projectile and target combinations. One of the means to access and study
the structure/properties of such nuclei is nuclear fission. Thermal neutron induced
fission fragment spectroscopy provides access to these difficult-to-reach nuclei to
study their medium- and high-spin nuclear structures in detail. Additionally, decay
spectroscopy of the neutron-rich fission fragment nuclei is instrumental in
revealing/affirming the decay chain of isotopes and low-spin structures of daughter
nuclei from the primary fission fragments. This facility has now been opened up to he potential users from other Indian institutes and universities. Under the first
ongoing National Experimental Users’ Campaign (since Oct. 2024), sixteen (16)
experiments, with each spanning 5-7 days of round-the-clock beam-time on
average, have been successfully carried out by research groups from institutes
and universities. Data are being analyzed, simultaneously, by the user groups at
their respective places. An overview of this facility, some recent outcomes, nuclear
structure research activities at NPD, BARC, and future possibilities under
collaborative research will be presented during the workshop.
