Gamma Spectroscopy ( HPGe Detector ) in Educational & Research Institutes in India.
Radioactive source produce gamma rays which can be detected and quantified by spectroscopy system.
This system can be either laboratory based or hand held mobile systems.
The system consists of radiation detector coupled with MCA and Spectroscopy software.
The radiation detector can be either Scintillation Detectors like NaI(Tl) or High Purity Germanium( HPGe) Detectors.
We will undertake status of HPGe detector based Gamma Spectroscopy System (GSS) in India.
Manufacturers Of HPGe Detector Based GSS:
There are only four manufacturers of these systems worldwide. These are:
- Canberra Instruments (Now Acquired by Mirion Technologies)
- Ortec Instruments ( Ametek Inc, USA)
- Baltic Scientific Instruments, Latvia
- Itech Instruments, France (Acquired PGT Inc, USA)
ISSUES IN OPERATION & MAINTENANCE OF HPGe BASED GSS:
- In India most GSS system are cooled by Liquid Nitrogen. In 30 liter Dewar refill of LN2 is required every 15 days. In ideal situation automatic LN2 pumps should do this function but this is done manually in India. During refilling condensation of LN2 on outer surface is causing degradation of detector performance.
- In few institutes availability of LN2 is an issue.
- Trained Technical Manpower to operate or troubleshoot in educational institute is an issue.
- After Sales Service capability with local distributors is absent so emphasis is to sell.
- Basic maintenance service is provided but high cost, longer wait time and unavailability of loner unit is an issue.
- Few institutes are “center of excellence” but knowledge transfer and sharing within community is limited.
- Mechanical Parts and electronic spares can be developed in India to increase reliable and uptime of these systems.
- Training on gamma spectroscopy software is not purchased by end users. This results in sub-optimal utilization of complete system.
- Most often funding to institutes are given by DAE but after project is Completed there is poor utilization of these instruments. We can either do pooling or share the resources once the project is completed
COMPONENTS OF HPGe BASED GSS:
- P-Type or N-Type HPGe detector.
- Lead Shield
- Multi Channel Analyzer
- Gamma Spectroscopy Software
- Personal Computer
PRICE OF HPGE BASED GSS:
Normally the starting cost of these system will be 25,000 US$ but can go upto 150,000 US$ depending on relative efficiency of detector selected, type of lead shield, MCA and software selected.
HOW CAN COST BE OPTIMIZED?
- Find local supplier for lead shield. This item is quite heavy and local fabrication can save freight cost.
- Select carefully your objective of research. This will help to choose correct detector. If we choose optimum detector we can save significant amount of money. Let me give an example. If your interest of isotope have energy above 40KeV and less than 3 MeV you can choose simple Co-axial P-Type detector but if we choose a detector which can detect isotopes having energy 3KeV onwards then special low energy detectors and cryostat with ULB lead shield will be required. To achieve this objective special materials and detectors will be custom made which can increase cost by minimum 40% to 50%. Thus if we have correct objective we can order correct detector and save on cost without compromising on our research.
- Hire independent consultants which can evaluate, negotiate and guide you in purchase process.
- Enter into extended warranty and ensure this is honored.
- Source and procure a pump and bake kit so that basic troubleshooting can be done at site.
- Source and procure electronic spare parts like FET and Pre-Amplifier from local market.
- Outsource ,if possible, the system to outside agencies which can run their samples or get training there by earning extra revenue to institute.
- Insist on automatic Liquid Ln2 monitor and pump so that better care can be taken.
- If you are using accelerator or other facility which needs continuous uptime I would advise to look for electronic cooling “ cryocoolers”. These are costly items but can be very useful for the final outcome of experiments.
LIST OF INSTITUTES:
I have tried to compile institutes where these instruments are present. I would request to provide feedback and support to maintain this list. If your institute is not mentioned here but have GSS please send your details and I would like to update this.
The idea is to make this list live so that entire community can share knowledge and expertise so that we can learn.
|NISER , Bhubaneswar
|Institute Of Physics , Bhubaneswar
|Tata Institute of Fundamental Research
|University of Mysore||http://www.uni-mysore.ac.in/physics/|
|University of Calicut,Physics Department||http://www.universityofcalicut.info/|
|Saha Institute of Nuclear Physics,Kolkatta||http://www.saha.ac.in/web/|
|UGC-DAE Consortium for Scientific Research||http://www.csr.res.in/csr_kolkatta.html|
|M L Sukhadia University, Physics department||www.misu.ac.in|
|MSU, Vadodara, Physics Department||http://www.msubaroda.ac.in/|
|National Institute of Oceanography,||http://www.nio.org|
|Indian Institute of Technology, Ropar
|Indian Institute of Technology, Roorkee
|Indian Institute of Technology, Kharagpur
|Delhi University, Physics Department
|IUAC , New Delhi
|Punjab University, Physics Department
|Banaras Hindu University, Physics Department
|Allahabad University, Physics Department
|Jadhavpur University, Physics Department
Isotope Hydrology Division
|Mumbai University, UM-DAE Center