Hydrogen pellet targets for circulating particle beams

Measurements of branching ratios for η decays into charged particles

“…The WASA-at-COSY experiment uses an internal target with frozen pellets injected at rates of several thousand per second [13]. Though vacuum pumps are positioned as closely as possible to the interaction region, a certain amount of residual gas is present in the region around the target which comes from the evaporation of pellets.…”

The PANDA detector at FAIR

“…As target, both, a hydrogen cluster jet target [3] (Fig. 2) and a hydrogen pellet target [4] with an areal density up to 10 16 atoms/cm 2 is foreseen, to reach the required luminosity and to allow the determination of the primary vertex. Both of them can also be operated with heavier elements.…”

Numerical Model of an Internal Pellet Target

“…Horizontal profile of the pellet beam is fitted satisfactorily by Gaussian function, distance between vacuum injection capillary and skimmer is nearly 0.7 m, distance from skimmer to beam axis is about 1.7 m [10], length between adjacent pellets particles is nearly constant with not very identified spread. These parameters are only approximate since most of them depend on detailed tuning of the source, used vacuum injection nozzle and many other conditions [1][2][3][4]10].…”

“…Such pellet target station is integrated in the WASA detector at the CELSIUS storage ring at The Svedberg Laboratory in Uppsala [1][2][3][4][5]. The target is in operation since 1999.…”