European Spallation Neutron Source

Documentation

Link to the Neutron Portal - ESS Documents

ESS Activity Report: 1st reporting period

A summary report outlining the activities of the different work packages within the ESS Preparatory Phase Project is now available

NeutronSourceESS Activity Report

February 2008

Current ESS proposal

The 5 MW LP ESS; best price-performance

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(Feri Mezei , Peter Tindemans, Klaus Bongardt )
Since the ESS project was formally presented in 2002, further considerations in the ESS Initiative have led to the conclusion that a 5 MW LP spallation source, upgradeable, would be the European option of choice. It is complementary to existing and planned sources, highly innovative, very cost-effective and is based on proven technologies. This has been endorsed by ESFRI and this is the facility that is on the ESFRI Road Map.

More recent investigations and simulations have only reinforced the conclusion of the ESFRI Neutron Working Group of early 2003 that such a facility would give Europe a world-leading position in many of the most vital areas of modern materials research.

The original ESS design was for a 10 MW proton accelerator on the basis of H- ion sources, with a 5 MW Short Pulse Target Station and a 5 MW Long Pulse Target Station, each with 20 instruments. The 5 MW LP ESS is a straightforward derivative of the 2003 ESS SC Reference Linac. Instead of H- ion sources there will be H+ ion sources; there is no SP Target Station and hence the accumulator ring is left out as well; the linear accelerator is exactly similar and the use for long pulse only opens up additional opportunities for optimization, such as selecting 1 GeV final energy of the protons instead of 1.34 GeV, which would make the superconducting accelerator section shorter. The Target Station for the 5 MW LP ESS is the same Target Station as the LP Target Station of the 2002/2003 design.

This paper analyses the 5 MW Long Pulse ESS and shows why this is the best facility to continue Europe’s world-lead in neutron science for a long time to come.

March 2010

5MW, 350/700 MHz  ESS LP linacs,  2 ms pulse every 60ms: with or without funnel

K.Bongardt: gratefully acknowledged are many fruitful discussions  with Feri Mezei and Peter Tindemans

Summary

The anticipated 5 MW ESS H⁺LP linac should be based on the accepted common European linac frequencies of 350/700 MHz to benefit from synergy with other discussed European multi MW linac projects. But special for ESS is the anticipated pulse structure as well as an upgrade possibility towards 7.5 MW beam power.  In order to allow for easier comparability, all discussed linacs have 2 ms pulse length and 16.67 Hz repetition rate, the optimized pulse structure for the ESS LP source, base for the overwhelming neutron performance, shown in Figure 1. (F. Mezei, New perspectives from new generation of neutron sources, C.R.Physique 8, No7-8, p. 909, 2007& H. Schober  et al, Tailored Instrumentation to Long Pulse Neutron Spallation Sources, NIMA 589, p.34,2008.) Choosing different pulse structure could be of advantage for same applications, but on average more beam power is required.

 

 

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