Ultra High Vacuum Technology Section

Accelerator Programme

Design, Development and Deployment of Vacuum Systems in Major Projects Indus, ARPF Linacs and IR-FEL:

1. Indus Accelerator Complex
1a. Microtron Vacuum System
  • Beam Energy : 20 MeV
  • Conventional circular design
  • Magnet pole diameter – 980 mm
  • Vacuum Chamber Material: Cylindrical Shell -SS316LN, Top & Bottom Dipole Faces-Low Carbon Electrical Grade Steel
  • Sealing : Viton O’ring
  • Operating pressure ~ 1E-6 mbar with beam, ~ E-7 mbar range without beam
  • Vacuum Pumps: SIP (270l/s, 400l/s)
  • Gauges: PIG, BAG
Fig-1:  Photograph of  20 MeV Microtron
1b. Booster Synchrotron Vacuum System
  • Beam Energy 450/550 MeV
  • Vacuum Envelope Circumference: 28.44 m
  • Operating Pressure: ~ 1E-7 mbar with beam, ~ E-8 mbar range without beam
  • Vacuum Chamber Material: SS304L
  • Vacuum Pumps :12 SIPs and 2 TMPs
  • Gauges: PIG-6nos
Fig-2: Photograph of Booster Synchrotron
1c. Indus-1 vacuum system
  • Vacuum Envelope Circumference: 18.96 m
  • All metal Bakeable System
  • Dipole Chambers: 04 Nos.
  • Vacuum Chamber Material: SS304L
  • Operating Pressure : ~1E-9 mbar with beam, ~ E-10 mbar range without beam
  • Vacuum Pumps:11 SIPs, 4 DIPs, 11 TSPs, 2 TMPs
  • Gauges : BAG- 4nos
Fig-3: Photograph of Indus-1 Storage ring
1d. Indus-2 vacuum system

Indus-2 (2.5GeV, 200mA) synchrotron radiation source consists of 172.43m long ultra-high vacuum (UHV) system to provide UHV environment to stored e-beam for its longer lifetime adequate for three shifts operation. It is the largest UHV system of country comprising of ~ 600 nos. of UHV components and instruments and running continuously round the clock 24x7 days since commissioning in year 2005. Over the years several upgradations of the system were done to accommodate various new devices including three undulators, four new kicker chambers, two new RF-cavities and vertical pinger magnet chamber. Beam lifetime of ~ 84 hr. with @2.5 GeV, 100 mA beam was achieved on October 23, 2019.

Salient features of Indus-2 vacuum system:
  • Vacuum Envelope Circumference: 172.40 m
  • Operating Pressure: ~1E-9 mbar with beam, ~ E-10 mbar range without beam
  • All metal Bakeable System
  • Vacuum Sectors : 14
  • Vacuum Chamber Material: Al alloys
  • Dipole Chambers: 16 Nos., Straight Section Chambers: 44 Nos.
  • NEG coated undulator chamber: 03 Nos.
  • Photon Absorbers: 64 Nos.
  • RF-Shielded Bellows: 44 Nos.
  • Vacuum Pumps: SIP-99 Nos., TSP-102 Nos.,
  • BAG - 54 Nos., RGA: 12 Nos.
  • RF contact Gate Valves: 14 Nos.
Fig-4a: View of Injection Section of Indus-2
Fig-4b: Dipole Chamber for Indus-2
Fig-4c: NEG coated Undultor Chamber
1e. Vacuum Systems of Undulators in Indus-2
  • Indus-2 ring has been upgraded with deployment of three insertion devices namely U1, U2 and U3 undulators in LS-2, LS3, LS5 straight sections.
  • Vacuum systems of these undulators were designed, developed and successfully installed within stipulated time schedule
  • Vacuum system of these undulators are identical and shown in Fig-5a (3D-schematic typical).
  • Material of undulator chamber: EN AW6060 -T6
  • End Flange of chamber: NW160-CF Bimetallic SS316L + AA6061-T6
  • UHV Pumping: Ti-Zr-V NEG thin film + SIPs
  • Chamber internal dimension: 81mm (W)x 17mm (H) racetrack
  • Length of chamber: 2700 mm for U1 and U2 and 2200 mm for U3
  • Operating Pressure ~ 1E-10 mbar with beam and in lower order of 1E-11 mbar without beam.
  • Activation Temperature & Time of NEG Film : 170C x 24 hr
Fig 5a: 3D model of  vacuum system of undulator
Fig 5b: Photograph of  installed U1 undulator in Indus-2 ring
Fig 5c: Photograph of  installed U2 undulator in Indus-2 ring
Fig 5d: Photograph of  installed U3 (APPLE-2) undulator in Indus-2 ring
2a. Vacuum System of Electron Accelerator based Radiation Processing Facility (ARPF)
  • Electron accelerator based demonstration radiation processing facility at Devi Ahilya Bai Holkar Fruit and Vegetable Mandi Complex, Indore consists of two electron linear accelerators (linacs) each of 10 MeV, 5 kW
  • Vacuum systems of both the linacs are identical and schematic layout is shown in Fig 6a.
  • Vacuum Envelope Material: SS316L, OFE Copper, Titanium
  • Operating Pressure: ~ 10-7 mbar range with beam
  • Vacuum Pump: SIPs (70 l/s)-04 Nos.
  • Gauge: Cold Cathode Full Range Gauge Pfeiffer PKR 251
Fig 6a:  Schematic of  ARPF Linac Vacuum System
2b. Vacuum System of Linac-3
  • Two vacuum Sectors
  • Vacuum Envelope Material: SS304L/316L, SS316LN, Al alloys, OFE Copper, Titanium
  • Operating Pressure: ~ 10-7 mbar range with beam
  • Vacuum Pump: SIPs (70 l/s)-05 Nos.
  • Gauge: Cold Cathode Full Range Gauge Pfeiffer PKR 251- 2 Nos
Fig 7:  Schematic of  Linac-3
3. Vacuum System of Infrared Free Electron Laser (IR-FEL)
  • Short pulse high power EM radiation in 12.5-50 µm wavelength band
  • Length of vacuum system: 17m
  • Four Vacuum Sectors: Linac section, beam transport line optical cavity and beam dump line
  • Operating Pressure: < 3x10-8 mbar with beam
  • Vacuum Envelope Material: SS304L, OFE Copper, AA6063-T6
  • Vacuum Pumps : SIPs (140 l/s-5 nos, 70 l/s-12 nos and 35 l/s- 2 nos)
  • Gauge: BAG – 11 Nos
Fig 8a:  Schematic layout of  IR-FEL Vacuum System
Fig 8b:  IR-FEL beam transport line
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