Access Type

Open Access Dissertation

Date of Award

January 2017

Degree Type


Degree Name



Physics and Astronomy

First Advisor

Giovanni Bonvicini


The Large Angle Beamstrahlung Monitor (LABM) is a device capable to monitor

the beam-beam collisions. The LABM measures the beamstrahlung light emitted

at large angle during the collisions of electron and positron beams. The properties

of the beamstrahlung, spectrum and polarization, are fundamentally related to the

size and relative position of the beams. Measuring the beamstrahlung, the LABM

delivers information about the size of the beams and their relative position at the

interaction point. The LABM will be part of the instrumentation of SuperKEKB,

a new e+e− collider that aims to reach the world record luminosity of 8×10^35 cm^-2 s^-1.

To achieve such luminosity, SuperKEKB will use the nano-beam scheme, which

allows for beams with a height of few tens of nanometers. In this framework, the

LABM represents an invaluable piece if instrumentation, allowing to measure the

size and relative position of the beams at run time and to adjust their position

in case of misalignment. The commissioning phase of the LABM took place in

parallel to the commissioning phase of SuperKEKB, starting in February 2016 and

ending in June 2016. During this phase no collisions took place and the LABM

was used to measure the background radiation produced by bending magnets. All

the components of the LABM where tested and the device has proved to work

as expected. A few upgrades will be installed at the end of 2017 to improve the

performance and the reliability of the device. The LABM will be ready and fully

operative at the beginning of 2018, when the first collisions will take place and

beamstrahlung light will be measured.