Company History.


CPO Ltd, UK Registered Company Number 04012016, was incorporated on 9 June 2000.

The Directors and Shareholders are F. H. Read and N. J. Bowring (since retired).

The Company Accountant is Mr. Steve Rhodes, Heywood Shepherd, 1 Park Street, Macclesfield, Cheshire SK11 6SR, UK.

The CPO programs were formerly marketed by RB Consultants Ltd, UK Registered Company Number 2813339 (full name Read and Bowring Consultants Ltd.), which was incorporated on 27 April 1993 and which has now been closed.


The copyright of all the CPO programs and associated User`s Guides is owned by CPO Ltd.


Email: [email protected]

Web site:


CPO Ltd gives no warranty that all errors have been removed from this or any related software or any documentation associated with the software, and neither the Company nor any of its employees, contractors or agents, nor the authors of the software give any warranty or representation as to the suitability or fitness of such software or any such program for any such program for any particular purpose nor shall be liable for any losses, whether they be direct, indirect, consequential, from damages, costs, expenses, claims or fees of any nature or kind resulting from any deficiencies, defects or errors in the software or the documentation or any related product.


The original author of the earliest electron optics computer programs at the University of Manchester, UK, was Frank Read, who was the leader of the Atomic and Molecular  Group (which would now be called the Quantum Physics Group).  Frank was an experimental physicist who used electron beams to fire at atoms and molecules.  He needed good data on electrostatic lenses to focus the electrons but discovered that the only available data in the literature was of poor quality because about half the time the principal planes did not cross, as they must do according to theory.  He therefore wrote an FDM program, which he could could not get to converge satisfactorily for the aperture lenses that he was using (this is now known to be because the FDM has difficulties in  simulating the singular fields near sharp apertures).  He therefore took a leaf from nature and realised that the fields are generated by the surface charges on the electrodes, and so wrote a 'charge density' program, now known to be a version of the BEM.  This worked well and formed the basis of all the later work on lens properties.  His main field was always experimental quantum physics, but he developed the early MAN-2D programs, with students, and is a co-author of the book Electrostatic lenses, by E Harting and F H Read, Elsevier Publishing Company, Amsterdam (1976).  He was later joined, see history of the company, by Nick Bowring who was a computer expert who had experience in interfacing programs to make them accessible to the general user.  He resigned from CPO Ltd in 2014.  Frank retired from physics in 2002 and since then has worked as an independent consultant engineer in charged particle optics.  He has more than 60 refereed papers on charged particle optics and instrumentation (one of them cited more than 500 times) and more than 150 on physics (about 10 of which have been cited more than 100 times).

Frank was joined in 2015 by Ryan O'Neill, who has redesigned the web pages and much else and has put new life into the venture.

The fore-runner program, MANION-2D, dates from about 1971. It was used to produce the data in the book Electrostatic lenses, by E Harting and F H Read, Elsevier Publishing Company, Amsterdam (1976).

Partnership Agreement between F H Read and N J Bowring signed 17 July 1992.

Agreement with Integrated Sensors Ltd (UMIST Ventures Ltd) on marketing and sales signed 25 Aug 1992.

Revenue sharing agreement with University of Manchester signed 1 Dec 1992.

RB Consultants incorporated 27 April 1993.

The first DBOS version of CPO3D was marketed in Sept 1993.

Space-charge option and other improvement added Aug 1994, and sent to existing users.

The first Windows version of CPO3D was marketed and also sent to existing users in March 1996.

2D versions included in June 1996.

A general update, including CPO2D, was sent to all existing users in April 1997.

Data -builder added June 1998.

A general update containing the data-builder was sent to all existing users in Dec 1998.

Following the resignation of Nick Bowring from the University of Manchester in 2000 and the early retirement of Frank Read (who is still connected as an Emeritus Professor), RBC Ltd was disbanded and CPO Ltd was started, on 9 June 2000.

A general update containing several new options was sent to all existing users in the autumn of 2000.

The Company continues to actively produce updates and upgrades.

Prof Bowring relinquished his activities and shares in the company in 2013, while Ryan O'Neill joined in 2015.