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Kumar, Vinit

First Lasing in an Infrared Free Electron Laser at RRCAT, Indore

Abstract Views :343 | PDF Views:82

Authors

K. K. Pant ¹, Vinit Kumar ¹, Bhaskar Biswas ¹, Arvind Kumar ¹, Shankar Lal ¹, Sona Chandran ¹, Saket Kumar Gupta ¹, Md. Khursheed ², Pravin Nerpagar ¹, A. K. Sarkar ¹, Ravi Kumar Pandit ¹, K. Ruwali ³, K. Sreeramulu ³, S. Das ³, R. S. Shinde ³, S. Chouksey ⁴, J. K. Parate ⁴, Viraj Bhanage ⁵, P. P. Deshpande ⁵, Shradha Tiwari ⁵, Mandar Joshi ⁶, Lalita Jain ⁵, Anand Valecha ⁷, Ayukt Pathak ⁵, M. A. Ali ⁵, H. R. Bundel ⁵, Purushottam Shrivastava ⁸, T. Reghu ⁸, Umesh Kale ⁸, Yashwant Wanmode ⁸, Praveen Mohania ⁸, Jaikishan Mulchandani ⁸, Akhil Patel ⁸, Mahesh Acharya ⁸, Ashish Mahawar ⁸, Mahendra Lad ⁹, M. K. Jain ⁹, Nitesh Tiwari ⁹, Pritam S. Bagduwal ⁹, V. G. Sathe ¹⁰, Sujata Joshi ¹⁰, Ram Shiroman ¹⁰, A. S. Yadav ¹⁰, Randhir Kumar ¹⁰, Alok Singh ¹¹, Vineet K. Dwivedi ¹¹, Mangesh Borage ¹², S. R. Tiwari ¹¹

Affiliations
1 Materials and Advanced Accelerator Sciences Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013, IN
2 Advanced Lasers and Optics Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013, IN
3 Accelerator Magnet Technology Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013, IN
4 Design and Manufacturing Technology Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013, IN
5 Laser Controls and Instrumentation Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013, IN
6 Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Mumbai 400 085, IN
7 Accelerator Control Systems Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013, IN
8 Pulsed High Power Microwave Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013, IN
9 Radio Frequency Systems Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013, IN
10 Ultra-High Vacuum Technology Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013, IN
11 Power Converters Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013, IN
12 Homi Bhabha National Institute, Raja Ramanna Centre for Advanced Technology, Indore 452 013, IN

Source

Current Science, Vol 114, No 02 (2018), Pagination: 367-373

Abstract

An Infrared Free Electron Laser (IR-FEL) designed to operate in the 12.5–50 μm wavelength band is presently in an advanced stage of commissioning at the Raja Ramanna Centre for Advanced Technology (RRCAT), Indore. Here we report results from first experiments on the IR-FEL after installation of its optical cavity, which has resulted in a power output that is ~105 times the expected spontaneous emission power for the beam parameters used in the experiment. The estimated out-coupled peak micro-pulse power during these experiments is ~2 kW. This is the first observed signature of lasing in the IR-FEL, and the first reported lasing in a FEL in India. This communication discusses the development of the IR-FEL, the recent experimental results, and the ongoing efforts to further increase the IR power to the design peak out-coupled power of 2 MW.

Keywords

Beam Parameters, Free Electron Laser, Infrared Power, Undulator.

Full Text

References

Cohn, K., Blau, J., Colson, W. B., Ng, J. and Price, M., Free electron lasers in 2015. In Proceedings of Free Electron Laser Conference, Korea, 23–28 August 2015, p. 625.

Kumar, V. et al., Design of an infra-red free electron laser at RRCAT. In Proceedings of InPAC, IUAC, New Delhi, 2011.

Kumar, A., IRFEL injector simulations. In Proceedings of InPAC 2009, RRCAT, Indore, 2009.

Kumar, G. et al., Installation, testing and commissioning of 10 kW pulse RF amplifier system @ 476 MHz using planar triode for IRFEL. In Proceeding of InPAC 2015, TIFR Mumbai, 2015; Tiwari, N. et al., Development and deployment of CW and pulse digital low level RF systems for accelerators at RRCAT. In Proceeding of InPAC 2015, TIFR Mumbai, 2015.

Praveen, M. et al., Design and development of low level S-band RF control system for IRFEL injector Linac. In Proceeding of InPAC 2015, TIFR Mumbai, 2015; Shrivastava, P., Status of 24 MW microwave system and LLRF control for IR-FEL linac. RRCAT Newsl., 2016, 29(1).

Singh, A. et al., Power supplies for IRFEL beam transport line magnets. In Proceeding of InPAC 2015, TIFR, Mumbai, 2015.

Saini, R. S. et al., Electron beam optics design of variable energy beam transport line for a tunable infra-red free electron laser at RRCAT. In Proceedings of InPAC 2011, IUAC, New Delhi, 2011.

Enomoto, A. and Dael, A., Technical Report – Lure Anneaux TF.CLIO/88-02 et CERA. 88-97/CLIO, Orsay, France, 19 May 1988.

Kailash, R. et al., Development of magnets for infra-red free electron laser project at RRCAT. In Proceeding of InPAC 2015, TIFR Mumbai, 2015.

Causes and Consequences of Rishiganga Flash Flood, Nanda Devi Biosphere Reserve, Central Himalaya, India

Abstract Views :177 | PDF Views:88

Authors

Manish Mehta ¹, Vinit Kumar ¹, Kalachand Sain ¹, Sameer K. Tiwari ¹, Amit Kumar ¹, Akshaya Verma ¹

Affiliations
1 Wadia Institute of Himalayan Geology, Dehradun 248 001, IN

Source

Current Science, Vol 121, No 11 (2021), Pagination: 1483-1487

Abstract

On 7 February 2021 at 10:30 am, a huge amount of slurry material flooded the Rishiganga catchment, resulting in excessive flow along the valley. The main cause of this flood was the dislocation of a huge rock mass approximately 540 m wide and 720 m long from the main rock body, which slipped down towards the Raunthi Gadera valley floor, causing massive devastation in the areas such as Raini, Tapovan, and Vishnuprayag. This event was not expected and was the first event in history when a flash flood occurred in winter. In this study, we tried to answer two major questions which are not been explained so far that are related to this disaster. These questions are (i) why did this event occur in winters? (ii) where did so much debris and water come from?. This study clearly answers these questions based on field observations

Keywords

Flash Flood, Himalaya, Nanda Devi, Raunthi Gadera, Rishiganga.

Full Text

References

Mehta, M., Shukla, T., Bhambri, R., Gupta, A. K. and Dobhal, D.

P., Terrain changes, caused by the 15–17 June 2013 heavy rainfall in the Garhwal Himalaya, India: a case study of Alaknanda and Mandakini basins. Geomorphology, 2017, 284, 53–71.

Valdiya, K. S., Paul, S. K., Tara, C., Bhakuni, S. S. and Upadhyay, R. C., Tectonic and lithological characterization of Himadri (Great Himalaya) between Kali and Yamuna rivers, Central Himalaya. Himalayan Geol., 1999, 20, 1–17.

Dobhal, D. P., Gupta, A. K., Mehta, M. and Khandelwal, D. D., Kedarnath disaster: facts and plausible causes. Curr. Sci., 2013, 105(2), 171–174.

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Kumar, V., Shukla, T., Mehta, M., Dobhal, D. P., Bisht, M. P. S. and Nautiyal, S., Glacier changes and associated climate drivers for the last three decades, Nanda Devi region, Central Himalaya, India. Quaternary Int., 2021, 575–576, 213–226.

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Sinha, A. K., Geology of the Higher Central Himalaya, John Wiley, Chichester, UK, 1989, p. 236.

Sain, K. et al., A perspective on Rishiganga–Dhauliganga flash flood in the Nanda Devi Biosphere Reserve, Garhwal Himalaya, India. J. Geol. Soc. India, 2021, 97, 335–338.

Shugar, D. H. et al., A massive rock and ice avalanche caused the 2021 disaster at Chamoli, Indian Himalaya. Science, 2021, 373, 300–306.

Agarwal, A. and Chak, A. (eds), Floods, Flood Plains and Environmental Myths, State of India Environments: A Citizen’s Report, Centre for Science and Environment, 1991, vol. 3, p. 167.

Wasson, R. J., Sundriyal, Y. P., Chaudhary, S., Jaiswal, M. K., Morthekai, P., Sati, S. P. and Juyal, N., A 1000-year history of large floods in the Upper Ganga catchment, central Himalaya, India. Quaternary Sci. Rev., 2013, 77, 156–166.

https://www.nationalheraldindia.com/india/uttarakhand-disaster-55bodies-recovered-so-far-179-missing-person-reports-lodged (accessed on 15 February 2021).

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