For the first time ever, an experimental nuclear physics research paper written by Vietnamese scientists has been published in the prestigious, leading international journal, the Physical Review C, where almost all the important new research from all over the world is recorded. Their new discoveries are reported to be of major importance in nuclear structure and astrophysics research.
The nuclear reactor at Dalat, where the experiments were carried out. Photo: Gia Binh
New discovery of important value
The Vietnamese scientists also judged this work vital for the development of the new nuclear reactor to be built by the Center for Nuclear Science and Technology, which the Vietnamese government recently approved.
The eight authors were: Dr. Nguyen Ngoc Anh, Dr. Nguyen Xuan Hai, and Ho Huu Thang, associates at the Vietnam Atomic Energy Nuclear Research Institute; Associate Professor Nguyen Quang Hung from DTU; Associate Professor Pham Dinh Khang from the Hanoi University of Science and Technology; and Professor Le Hong Khiem from the Institute of Physics at the Vietnam Academy of Science and Technology.
In addition, Dr. A.M. Sukhuvoj and Dr. L.V. Mitsyna from the Joint Institute for Nuclear Research in Dubna, Russia, also shared part of the work, but the design, assembly, measurements, data processing and paper preparation were all conducted in Vietnam by the Vietnamese team alone, who handled all the experimental work.
The research began in December 2016 and ran until July 2017. “The first version of the manuscript was submitted to the Physical Review C journal in February 2019,” explained Dr. Anh. “This was followed by verification and assessment of the paper by the National Nuclear Data Center at the Brookhaven National Laboratory in the US, with two rounds of refereeing with many corrections. On August 15, the paper officially appeared in the journal.”
The most important discovery of the research was the identification of 74 primary transitions, 61 excitation levels, and 291 secondary transitions, completely new additions to the international nuclear data library, ENSDF.
“The new data will be used to improve the accuracy and veracity of reaction speeds and reaction cross- section computations,” explains Associate Professor Hung. “These are vital in the construction of nuclear reactors, to create nuclear fuel and treat nuclear waste, but are also very important in Astrophysics research.”
Front: Associate Professor Khang (left). Back, from left to right: Dr. Anh (2nd), Dr. Hai (4th), and Associate Professor Hung (5th). Photo: NVCC
Doing away with idea that “Vietnam can never conduct nuclear physics research”
“Research centers in developed countries have modern equipment, such as high-energy accelerators and high-power experimental reactors,” explains Associate Professor Khang to Thanh Nien. “These cost from tens of millions to billions of dollars, including the cost of numerous specialized staff and major ongoing operating expenses, using the latest measurement devices, electronics systems and advanced computer systems, complemented with teams of top international experts.”
Associate Professor Khang also stated that the Vietnamese experimental nuclear physics research community is still small, with only one 500 kilowatt reactor in Dalat, which is almost sixty years old. There are also limited quantities of high-resolution detectors and signal processing electronics, most of which have deteriorated after long use without upgrades. These limitations have brought many people to assert that “Vietnam can never conduct nuclear physics research”.
However, scientists used neutron bundles from the Dalat nuclear reactor, combined with old electronics systems to perform experiments to measure the thermal neutron capture of different nuclei. To do this, they needed to build their own measurement equipment and neutron guide systems, assembled from spare parts from previous projects.
“Our research results are vital for the intensive and efficient operation and training of our experts at the new reactor.” Associate Professor Khang explains, “According to its design specifications, the new nuclear reactor will have from 10 to 15 milliwatts of power, twenty to thirty times that of the Dalat facility. To be able to publish our results internationally, we required at least one year taking measurements. Similar experiments carried out using the new reactor will require much shorter processing times and improve the quality of our research. Furthermore, this research will allow us to train an internationally-recognized research team on our own, without the need to spend money sending our staff to study overseas.”
(Media Center)