R71 Phonon Energy Partitions

Bulk 60keV events were selected with cuts on the Q1 energy range, Psum energy range. An additional cut was made requiring either a high PFS2 or PBS2 fraction depending on the source position. Phonon channels all have relative calibration applied. X and Y partitions use the difference of balanced P*OFamps quantities for the 4 inner-ring channels B,C,D, and E.

Phonon xy partitions in -4/+4 V data.

Compared to the delay-based xy quantities, the energy partitions appear insensitive to changes in event position within a single channel. In other words, these energy partitions can discriminate which channel an event is under, but are not sensitive to the position within that channel. So, when events are anywhere under channel F, the inner ring channels (on a given face) all see about the same amount of energy. Similarly, when the events move into the inner ring, the channels they are under receive more energy, but that amount is somewhat unaffected by the event position within the channel.

In future runs, carefully study of how these quantities change near the channel boundaries and with changing voltage bias could allow measurement of transport properties like NLT phonon emission angles.

A similar story emerges with the radial partitions. The balance of energy seen by the channels only changes appreciably when the events move beneath a different sensor.

Phonon radial partitions in -4/+4 V data.