Konstantin Sukharnikov Scientific instrumentation

A hobby. An independent overview compiled from public sources by a science and space enthusiast. I am not involved in these missions or facilities; my own work is detector electronics at European XFEL. My projects →

Facility · Synchrotrons

SOLEIL / SOLEIL II

2.75 GeV storage ring, to become SOLEIL II (emittance from 3,900 to 90 pm·rad)

Status
Operating
Location
Saint-Aubin (Paris-Saclay plateau), France
Operator
Synchrotron SOLEIL (CNRS, CEA)
Next
Oct 2028 SOLEIL shuts down; SOLEIL II "dark period" (about two years including commissioning)

Summary

France's 2.75 GeV synchrotron. SOLEIL II brings a new ultra-low-emittance ring and a new booster at the same energy: natural emittance from 3,900 to 90 pm·rad (L. Nadolski, ESLS 2025); it extends the facility's life by at least 15 years (SOLEIL II).

Now as of 9 Nov 2026

Preparing for the shutdown. The RF roadmap: conditioning from August to December 2026; the first two 352 MHz cavities installed in the present ring in July–August 2027; the first 1.4 GHz harmonic cavity in January 2028; SOLEIL shuts down in October 2028 (ESLS 2025). The dark period starts in October 2028 and lasts about two years including commissioning (DEELS 2026, N. Hubert). Users would return around the end of 2030; this is an estimate from those dates, and no official date has been found.

Key dates

  1. Aug–Dec 2026RF conditioningas planned
  2. Jul–Aug 2027First 352 MHz cavities in the present ringplanned
  3. Oct 2028SOLEIL shuts down, dark period beginsplanned
  4. ≈ 2030 (end)Users returnestimate

Timeline

  1. 24 Mar 2026DEELS: dark period from October 2028 for about two years — Indico PSI
  2. 30 Oct 2025Status of SOLEIL and SOLEIL II at ESLS 2025 — slides