There is, as mentioned above, the Book, "They also serve who stand and wait" which tells the story of the depot. The link in the first post is not working so this should be better.
Books about US Army camps and hospitals in the Midlands of the UK during World War II, also USAAF bases, written by Mart and Fran Collins
www.englemed.co.uk
As Pheasey was used as a sub depot of Whittington you may get an idea of the use from the book....LICHFIELD: The U.S. ARMY ON TRIAL by Jack Gieck
Geick tells of the terrible atrocities committed at Whittington and the subsequent trial. He refers to the "Beast of Lichfield.”
Whittington Barracks was handed over in 1942 to the US as a staging area for the allied invasion of Normandy. After D-Day the facility became a "reinforcement depot" where individual or "causal" replacement soldiers were sent to be processed for re-assignment to combat units, which had become depleted because of casualties.
Between Sept 1942 and Sep 1945 when the base was returned, some 340,000 American troops passed through..... a significant portion, especially in the later years had been wounded in combat, and recently been released from hospitals.
“...some of early the shipments to Lichfield were actually made up of prisoners who had been convicted by military courts in the US of armed robbery, assault, rape, car theft, burglary, and other criminal offencies....Lichfield cadre learned to be tough as nails in handling their temporary charges, and they did not distinguish between individuals.”
Jack Geick does not mention Pheasey but at Whittington the coloured soldiers were segregated and were accomodated in tents