IPAC2021 - List of Authors (Krishnagopal, S.)

Paper	Title	Page
MOPAB318	Beam Characterization of Five Electrode ECR Ion Source	980
	H.M. Kewlani, S. Gharat, S. Krishnagopal, J.V. Mathew, S.V.L.S. Rao BARC, Mumbai, India B. Dikshit, H.M. Kewlani, S. Krishnagopal Homi Bhbha National Institute (HBNI), DAE, Mumbai, India
	A five electrode ECR Ion Source (ECRIS) was developed for the Low Energy High-Intensity Proton Accelerator (LEHIPA) at BARC. The ECRIS is operated at the energy of 50 keV with a beam current of 20 mA. The ECRIS characterization is done for the beam current, beam emittance, and proton fraction in continuous and pulse beam operation. The pulsed beam operation of the ion source starting from 500 µs to 200 ms of pulse on time with a repetition rate of 1 to 10 Hz. The transverse beam emittance measurement is done by using an Allison scanner. The beam emittance characterization experiments are conducted by varying applied microwave power to the plasma, operating gas pressure of plasma and puller voltage. The measured beam emittance is in the range of 0.3 pi.mm. mrad to 0.4 pi.mm. mrad for 50 keV beam. In this paper beam emittance experiment setup and results are discussed.
	Poster MOPAB318 [2.496 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB318
About •	paper received ※ 19 May 2021 paper accepted ※ 10 June 2021 issue date ※ 16 August 2021
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MOPAB321	Schlieren Imaging for Flow Visualisation of Gas Jet in Vacuum for Accelerator Applications	989
	S. Rosily, B. Dikshit, S. Krishnagopal Homi Bhbha National Institute (HBNI), DAE, Mumbai, India S. Krishnagopal, S. Rosily BARC, Mumbai, India
	Schlieren imaging was explored for flow visualising of a gas jet in vacuum for beam profile monitor application. In supersonic gas jet based beam profile monitors, the high density jet flows through various differentially pumped skimmer stages before being shaped into a sheet. Schlieren imaging is a well known technique used in aerodynamic studies to visualise gas flow. This technique is explained in the paper along with a gist of other flow visualisation techniques. An Z-type schlieren imaging setup used to view the high density flow features of a pulsed supersonic gas jet inside vacuum is described in detail. Flow around a Pitot probe in supersonic flow was simulated and the resultant density profile obtained was compared with the image obtained using schlieren imaging. The flow features including a detached shock around the tip of the probe was observable at medium and high vacuum after processing the image. Image processing algorithms and tools useful for this application are also discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB321
About •	paper received ※ 20 May 2021 paper accepted ※ 26 May 2021 issue date ※ 29 August 2021
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MOPAB322	Electronics for Bead-pull Measurement of Radio Frequency Accelerating Structures in LEHIPA	993
	S. Rosily, S. Krishnagopal Homi Bhbha National Institute (HBNI), DAE, Mumbai, India S. Krishnagopal, S. Singh BARC, Mumbai, India
	For carrying out bead-pull characterisation of RFQ and DTL at the Low Energy High Intensity Proton Accelerator of BARC, a controller for simultaneous motion of 64 axis, tuners or post couplers, was developed. Also, a bead motion controller with integrated phase measurement sensor was developed. The paper discusses the requirements of the system, the architecture of the control systems, operation and results. The results obtained from the sensor was compared to that obtained using an independent USB VNA. The advantages of the system especially with addition of internal phase measurement sensor including minimising position error, flexibility in beadpull to selectively increase resolution at specified locations and ease of implementing auto-tuning algorithms are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB322
About •	paper received ※ 20 May 2021 paper accepted ※ 24 May 2021 issue date ※ 14 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Beam Characterization of Five Electrode ECR Ion Source

980

H.M. Kewlani, S. Gharat, S. Krishnagopal, J.V. Mathew, S.V.L.S. Rao
BARC, Mumbai, India
B. Dikshit, H.M. Kewlani, S. Krishnagopal
Homi Bhbha National Institute (HBNI), DAE, Mumbai, India

A five electrode ECR Ion Source (ECRIS) was developed for the Low Energy High-Intensity Proton Accelerator (LEHIPA) at BARC. The ECRIS is operated at the energy of 50 keV with a beam current of 20 mA. The ECRIS characterization is done for the beam current, beam emittance, and proton fraction in continuous and pulse beam operation. The pulsed beam operation of the ion source starting from 500 µs to 200 ms of pulse on time with a repetition rate of 1 to 10 Hz. The transverse beam emittance measurement is done by using an Allison scanner. The beam emittance characterization experiments are conducted by varying applied microwave power to the plasma, operating gas pressure of plasma and puller voltage. The measured beam emittance is in the range of 0.3 pi.mm. mrad to 0.4 pi.mm. mrad for 50 keV beam. In this paper beam emittance experiment setup and results are discussed.

Poster MOPAB318 [2.496 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB318

About •

paper received ※ 19 May 2021 paper accepted ※ 10 June 2021 issue date ※ 16 August 2021

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPAB321

Schlieren Imaging for Flow Visualisation of Gas Jet in Vacuum for Accelerator Applications

989

S. Rosily, B. Dikshit, S. Krishnagopal
Homi Bhbha National Institute (HBNI), DAE, Mumbai, India
S. Krishnagopal, S. Rosily
BARC, Mumbai, India

Schlieren imaging was explored for flow visualising of a gas jet in vacuum for beam profile monitor application. In supersonic gas jet based beam profile monitors, the high density jet flows through various differentially pumped skimmer stages before being shaped into a sheet. Schlieren imaging is a well known technique used in aerodynamic studies to visualise gas flow. This technique is explained in the paper along with a gist of other flow visualisation techniques. An Z-type schlieren imaging setup used to view the high density flow features of a pulsed supersonic gas jet inside vacuum is described in detail. Flow around a Pitot probe in supersonic flow was simulated and the resultant density profile obtained was compared with the image obtained using schlieren imaging. The flow features including a detached shock around the tip of the probe was observable at medium and high vacuum after processing the image. Image processing algorithms and tools useful for this application are also discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB321

About •

paper received ※ 20 May 2021 paper accepted ※ 26 May 2021 issue date ※ 29 August 2021

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPAB322

Electronics for Bead-pull Measurement of Radio Frequency Accelerating Structures in LEHIPA

993

S. Rosily, S. Krishnagopal
Homi Bhbha National Institute (HBNI), DAE, Mumbai, India
S. Krishnagopal, S. Singh
BARC, Mumbai, India

For carrying out bead-pull characterisation of RFQ and DTL at the Low Energy High Intensity Proton Accelerator of BARC, a controller for simultaneous motion of 64 axis, tuners or post couplers, was developed. Also, a bead motion controller with integrated phase measurement sensor was developed. The paper discusses the requirements of the system, the architecture of the control systems, operation and results. The results obtained from the sensor was compared to that obtained using an independent USB VNA. The advantages of the system especially with addition of internal phase measurement sensor including minimising position error, flexibility in beadpull to selectively increase resolution at specified locations and ease of implementing auto-tuning algorithms are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB322

About •

paper received ※ 20 May 2021 paper accepted ※ 24 May 2021 issue date ※ 14 August 2021

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)