Industrial Accelerators Section
50,000 LITERS Liquid Nitrogen Storage Tanks

Two 50,000 liters Liquid Nitrogen tanks were designed and manufactured in 1998 and were the "First Indian Contribution" made to Large Hadron Collider (LHC) Project of European Organization for Nuclear Research (CERN). The tanks were manufactured by INOX INDIA LIMITED, Baroda under the supervision of IMA Section.


Precision Magnet Positioning System (PMPS) Jacks

LHC has more than 1600 superconducting magnets along its 27 km circumference for bending focusing the beams. Each magnet weighs more than 32 tons and has a length of 15 meters. Under an agreement between Department of Atomic Energy (DAE) of Government of India and CERN, Raja Ramanna Centre for Advanced Technology (RRCAT) Indore has been entrusted the task of developing a number of subsystems for the LHC. As part of this effort IMA Section carried out design, development and supply of more than 6800 alignment jacks for the huge magnet assemblies of LHC. These magnet assemblies are positioned with a displacement resolution of 50 micrometer all along the 27 km length using these jacks.
These devices called Precision Magnet Positioning System (PMPS) jacks, enable one person to move the huge magnet and position it with a very high setting resolution comparable to the breadth of human hair. The jacks have to maintain these positions for a long time under the action of variable transverse forces. In fact the set position should remain within 100 micrometer when the transverse force reaches a value of 0.5 ton and within 1 mm under a very severe transverse load of 8 tons.


  

Stringent International standards have been followed to ensure quality and safety of the product. The supply of all the 6800 jacks was completed in June 2005.


Structural Analysis Of Short Straight Section

The twin-quadrupole, 6 meters long, 8 tons Short Straight Section of LHC experiences relative displacements between its cold magnet and its external vacuum vessel during alignment. A finite element model consisting of vacuum vessel, large sleeve, vacuum jacket & internal piping of jumper, interconnection bellows, composite supports & alignment jacks using beam, link, shell and solid elements was developed to quantify the relative displacements. A dedicated experiment with a 40 meters long setup was carried out at CERN to validate the FE Model.


Short Straight Section with its Subsystem

Finite Element Model
The FE model gives out a relationship between the individual jack movement and cold mass positions.

Full Experimental Setup

Dials Mounted during the experiment

The work has been concluded and is being used at CERN. IMA Section is now extending this study to include the effect of large jumpers that are being used in some of the designs of Short Straight Sections.


Motorizable High Precision Motion Adaptors & Jacks for Inner Triplets

After RRCAT successfully developed and supplied compound motion alignment jacks for LHC ARC magnets, CERN and RRCAT agreed to extend the work for the inner triplets of the LHC under DAE-CERN collaboration. The inner triplet system provides the final focusing of the proton beams before collision at four locations in the machine. Each inner triplet consists of 3 quadrupole optical elements. The quadrupoles of the inner triplet focus the beams to small spot sizes, about 0.016 mm. The displacement resolution (horizontal / vertical axis) required is less than 0.01 mm for the alignment of these 18-ton magnets. In addition, the alignment has to be done remotely during small beam-on maintenance intervals.
The added requirements for the inner triplets jacks were the higher setting resolution of 0.01 mm, development of adaptors for motorization of jacks in vertical and transverse directions, and short mounting & dismounting time for the adaptors due to high radiation environment.
The work done includes enhancing the setting resolution of 0.05 mm of the arc jacks to the inner triplet requirement of 0.01 mm, development of a compact mechanical adaptors and developing the interfaces for motorization.



The vertical adaptors are extremely compact precision lifting devices having a high load capacity of 10 tons and setting resolution better than 0.01 mm. These adaptors are assembled with the jacks, and two stepper motors- one each for vertical and transverse movement- are coupled to these adaptors. Three such jacks support each magnet. The integrated alignment system consisting of jacks, pre-series vertical & transverse adaptors supplied by RRCAT, and motors & its control unit provided by CERN, was successfully tested on a dedicated test set-up under a RRCAT-CERN joint test campaign in June 2005 at CERN.

Best viewed in 1024x768 resolution