Radiation Shielding:

Design, fabrication & installation of radiation shielding arrangements for Indus machine is the responsibility of the group. Radiation shielding is one of the most important aspects in the design high-energy storage rings to protect working personnel from high energetic, highly penetrating radiation.

Radiation shielding design:

• Microtron Block and Booster Hall:

  • Pre-injector (Microtron) & Booster synchrotron of Indus-1 facility is located in a zone fully enclosed with thick concrete walls & modular roof.
• Transport line-2 (TL-2) and Indus-1 storage ring Area:

  • Storage ring and transport line-2 is located in the main hall of the Indus-1 building. A novel design for the Indus-1 radiation shielding was evolved and implemented in May 1999, after commissioning of Indus-1 synchrotron radiation facility . This design is a combination of Hybrid structures (lead + Mild steel) for compactness and multiple mazes (concrete) for making labyrinths/maze provides flexibility in modification and quick installation.
• Transport line-3 (TL-3) Tunnel:

  • The electron beam from booster is extracted through Transfer Line-2, for subsequent injection into Indus-2 ring via Transfer Line-3 (TL-3). In order to prevent inadvertent transmission of electron beam, a radiation shutter (beam absorber) has been developed and installed near the beginning of TL-3 in Indus-1 Storage Ring area. The beam absorber is made of DENSIMET alloy, which inside a vacuum chamber using a pneumatic drive remotely controlled from Indus-2 control room (Ref 3). A sliding type shielding door (filled with lead bricks) was installed to absorb the x-rays coming from transport line components through door opening. This door weighing ~4 tones is suspended from a girder (ISMB 300) using push-pull type trolleys and driven by a pneumatic cylinder at a speed of about 3m/min.
• Storage ring, Indus-2:

  • The annular ring shaped building for SRS ring has been constructed by casting concrete in curved walls of thickness ranging from 0.6m on inner side and 1.5m towards the experimental area with roof thickness 0.6m.
• Experimental Hall, Indus-2:

  • Synchrotron radiation (SR) coming from bending magnets of Indus-2 SRS is in Infrared to X-ray region of which radiation with energy varying from few eV to 40 keV comes under the category of ionizing radiation. When SR beam is brought out in beam line, the shielded hutch (which encloses the entire beam line) is required for the protection for personnel against the radiation hazards from SR and bremsstrahlung radiation. The shielding hutches are fabricated out of steel/lead sheet panel in modular construction with provision to add or remove the lead sheet based on the radiation survey. Radiation tightness at the joints of the panel structure, doors, viewing windows, penetrations, junctions between the hutch and the concrete floor slab and walls, and junctions between the roof and the walls of the hutches was ensured. Effectiveness of the radiation shielding design is validated by survey results that indicate that doses are within limits set by regulatory board (AERB).

SPECIFICATION OF RADIATION SHIELDING IN Indus COMPLEX:

SUMMARY OF IMPORTANT RADIATION MATERIAL USED IN Indus COMPLEX: