Performance demonstration of the PEnELOPE main amplifier HEPA I using broadband nanosecond pulses

We report on the energetic and beam quality performance of the second to the last main amplifier section HEPA I of the PEnELOPE laser project. A polarization coupled double-12-pass scheme to verify the full amplification capacity of the last two amplifiers HEPA I and II was used. The small signal gain for a narrow-band continuous wave laser was 900 and 527 for a broadband nanosecond pulse, demonstrating 12.6 J of output pulse energy. Those pulses, being spectrally wide enough to support equivalent 150 fs long ultrashort pulses, are shown with an excellent spatial beam quality. A first active correction of the wavefront using a deformable mirror resulted in a Strehl ratio of 76% in the single-12-pass configuration for HEPA I.

Peer Assisted Study Support (PASS) and Students as Change Agents (SACA) in Mathematics at the University of Nottingham

In 2015-16, a Peer Assisted Study Support (PASS) scheme was introduced in Mathematics at the University of Nottingham. This PASS scheme is intimately linked to the University’s Nottingham Advantage Award (NAA) scheme, which recognises a wide range of students’ extracurricular activities, including serving as a PASS Leader. Furthermore, the PASS scheme has been developed in conjunction with the NAA’s Students as Change Agents and Change Leaders (SACA and SACL) programmes, which recognise student-staff partnerships that change teaching and learning practice. Essential to the success of the scheme has been its genesis through a student-staff partnership, in particular two summer internships in 2015 to develop PASS materials, supported by the Sigma Network and the University’s Teaching Transformation Programme.

Precision Turning with Slender Boring Bars

The paper presents a new method for achieving high accuracy in finish turning with slender tools in turning operations. The method is developed for high-accuracy machining with vibrations-damped boring bars with a length-to-diameter ratio up to 14. The method is based on a three-pass scheme where the deflection of the boring bar is calculated and compensated for in the finishing passes. The method shows very good results for a great variation of cutting conditions.