TUPYP002
LNLS, Campinas, Brazil
CNPEM, Campinas, SP, Brazil
Due to equipment safety at Sirius, the Brazilian 4th generation synchrotron light source, there are conditions where the need to interrupt the beam being provided by the storage ring to the beamline is mandatory. To minimize the duration and quantity of storage ring beam interruptions as the number of beamlines increases, the installation of a new shutter was proposed between the storage ring and the beamline’s front end. This work presents an overview of the project motivation, modes of failures and their effects, project validation, device operation, and preliminary results.
L. C. Arruda et al., "Equipment and Personal Protection Systems for the Sirius Beamlines",ICALEPCS’21, Shanghai, China, Oct. 2021.
LNLS, Campinas, Brazil
Sirius’ long beamlines are equipped with cryogenic cooled optics to take advantage of the Silicon thermal diffusivity and expansion at those temperatures, contributing to the preservation of the beam profile. A series of improvements was evaluated from the experience in the employment of such cooling systems during the early years of operation. The main topic refers to the prevention of instabilities in the temperature of the optics due to variations in the liquid nitrogen cylinder pressure, refill automation or progressive variations of the convective coefficient into the cryostat. This work discusses the performance of these systems after optimizing the pressure of the vessels and their control logics, the effectiveness of occasional purges, cool down techniques, and presents the monitoring interface and interlock architecture. Moreover, we present the reached solution for achieving higher beam stability, considering liquid nitrogen flow active control (commercial and in-house). Also propose the approach for the future 350 mA operation, including different cooling mechanisms.
LNLS, Campinas, Brazil
CNPEM, Campinas, SP, Brazil
The SABIA beamline (Soft x-ray ABsorption spectroscopy and ImAging) will operate in a range of 100 to 2000 eV and will perform XPS, PEEM and XMCD techniques at SIRIUS/LNLS. Thermal management on these soft x-ray beamlines is particularly challenging due to the high heat loads. SABIA’s first mirror (M1) absorbs about 360 W, with a maximum power density of 0.52 W/mm², and a water-cooled mirror was designed to handle this substantial heat load. To prolong the mirror operation lifetime, often shortened on soft X-ray beamlines due to carbon deposition on the mirror optical surface, a procedure was adopted using high partial pressure of O₂ into the vacuum chamber during the commissioning phase. The internal mechanism was designed to be exactly constrained using folded leaf springs. It presents one degree of freedom for control and alignment: a rotation around the vertical axis with a motion range of about ±0.6 mrad, provided by a piezoelectric actuator and measured using vacuum compatible linear encoders. This work describes the SABIA’s M1 exactly constrained, high heat absorbent design, its safety particularities compared to SIRIUS typical mirrors, and validation tests results.