Timing System at MAX IV - Status and Development

A MAX IV construction of two storage rings (SR1.5GeV and SR3GeV) and a short pulse facility (SPF) has been proceeding over last years and will be finished in the middle of 2016. In 2014, few timing procurements were successfully finalized according to the MAX IV requirements (see [1] for details) and the installation works are ongoing along with the TANGO control system integration. The design covers the timing synchronization (TIM) and acquisition, fast orbit feedback (FOFB), fast machine protection system (FMPS) and integration of MAX IV operation modes. The LINAC commissioning started in 2014 and was successful together with the first beam line (FEMTOMAX). The SR3GeV commissioning started in August 2015 and is ongoing. The SR1.5GeV is being installed and will be commissioned in 2016. MAX IV OPERATION MODES MAX IV will work in 4 different modes: • LINAC 3GeV (LIN) • LINAC 3GeV + Short Pulse Facility (SPF) • LINAC 1.5GeV + Storage Ring 1.5GeV (SR1) • LINAC 3GeV + Storage Ring 3GeV (SR3) LIN and SPF are rated for 100Hz injection whereas SR1 and SR3 for 10Hz. Each mode is synchronized to its own radio frequency (RF). LIN and SPF are driven by 39 harmonics of the LINAC master oscillator (MO) 3GHz (2998500000/39=76884615.38Hz in reality, around 77MHz). The 39 harmonic is required for a synchronization of two laser systems, one at the beginning of the LINAC, other 400m away in the short pulse facility. This implementation also keeps the same constant phase for other frequencies: 100Hz LINAC injection trigger, 1kHz laser pumping frequency etc. SR1 is locked to 100MHz (RF1) and SR3 is locked to 100MHz (RF3) but those frequencies are a bit different as the real value comes from the construction and temperature parameters of storage rings. Both rings work in the same way, each SR TIM generates a LINAC injection trigger which is locked to its RF and in constant phase to its machine clock (MC). The MC phase shift (10ns step) defines the SR bucket number. SR3 stores 176 electron buckets and its MC is equal to 568kHz, whereas SR1 stores 32 electron buckets and its MC is equal to 3.12MHz. On top of that, the synchronization to mains electricity (ME) 50Hz will be implemented, so the injection will always be applied under constant parameters of high power devices. In summary, 3 different LINAC triggers are delivered: • LIN and SPF – TRIG0 (3GHz, 77MHz, 50Hz), • SR1 – TRIG1 (100MHz, 3.12MHz, 50Hz), • SR3 – TRIG3 (100MHz, 568kHz, 50Hz). The brackets include a set of frequencies which are synchronized one other. The future timing improvement considers adding 3GHz master oscillator (MO) to TRIG1 and TRIG3 (see “MO 3GHz SYNCHRONIZATION” section for more information).