The Insertion Device (ID) photon beam of a synchrotron can be contaminated with radiation from upstream and downstream bending magnets, causing position measurement errors in blade-type monitors. Beamlines of the low emittance storage ring are particularly sensitive to photon beam position variations, requiring more accurate measurements. To address this, we designed an ionization profile monitor to non-destructively measure the profile and position of the white undulator beam at Korea-4GSR without contamination. Leveraging the relatively large active area of readout devices suitable for small emittance beams we have designed a 1:1 mapping field to defocus photo-ions. Given that the defocusing field can induce errors due to vertical position, we propose a calibration method and validate it using particle tracking simulation.

A pepper-pot diagnostic device was developed to accurately and robustly retrieve particle distribution in horizontal and vertical phase spaces by single-shot emittance measurements. Two masks that differ in both composition and manufacturing method were fabricated: one made of phosphor bronze by an optical lithography process and another made of stainless steel (SUS) by laser cutting. Scanning electron microscope (SEM) measurements of the two masks revealed that the former is superior in terms of regularity and shape of the mask holes and is therefore more suitable to use. A new image-processing algorithm, cluster noise removal method, was developed which improves the resolution of the phase-space distribution measurements over traditional methods. The results show that the diagnostics can robustly and reliably retrieve the four-dimensional (4-D) phase-space distribution of ion beams with a single-shot measurement.