Beam test of the microscope prototype and active collimator preliminary report on the parasitic beam tests in Hall B April 2011 Richard Jones, Igor Senderovich, Brendan Pratt, James McIntyre, Fridah Mokaya, Alex Barnes, Chris Pelletier, John Turner, Anne-Marie Carrol, Jessica Hyde – University of Connecticut Alex Somov, Hovanes Egiyan, Jefferson Lab GlueX collaboration meeting, Bloomington, May 9-11, 2011

2 Outline Goals Preparations Run conditions Active collimator data Microscope prototype data Status of analysis and outlook

GlueX collaboration meeting, Bloomington, May 9-11,20113 Goals Active Collimator Measure the error of the beam centroid position as a function of the input filter bandwidth. Record the current on all four sectors in a pair of opposing quadrants simultaneously. Check that we have correctly understood the reason for anomalous peaks seen in the data from the 2007 beam test. Microscope Prototype Measure the light yield for a high energy electron moving along the axis of a fiber. Measure the TDC time resolution achievable using the UConn preamp, leading edge discriminator, F1TDC. Check the rate dependence (efficiency, time resolution) predicted by our simulation with real data.

GlueX collaboration meeting, Bloomington, May 9-11,20114 Preparations Construction of prototypes at UConn (reported before) Igor Senderovich, Brendan Pratt, James McIntyre, RJ drive down to JLab during Spring Break, installation begins. Active collimator installed in Hall B alcove Active collimator installed in Hall B alcove Alex SomovHovanes Egiyan UConn crew went home, leaving microscope in the hands of Alex Somov and Hovanes Egiyan. found DAQ crate, electronics found a DAQ computer that is legal built a CODA system from scratch designed and tested a readout trigger verified that everything worked reminded RJ not to worry built and tested trigger scintillator found the right hookups in Hall B got AC translation stage working with our labview-based DAQ had Hall B contacts to get it done with minimal disruption to them

GlueX collaboration meeting, Bloomington, May 9-11,20115 Preparations Construction of prototypes at UConn (reported before) Igor Senderovich, Brendan Pratt, James McIntyre, RJ drive down to JLab during Spring Break, installation begins. Active collimator installed in Hall B alcove Active collimator installed in Hall B alcove Alex SomovHovanes Egiyan UConn crew went home, leaving microscope in the hands of Alex Somov and Hovanes Egiyan. Microscope prototype installed under Hall B tagger Microscope prototype installed under Hall B tagger Both devices were tested during 6 intensive days of the photon tagger re-commissioning, Mar. 26 – 31. Both devices were tested during 6 intensive days of the photon tagger re-commissioning, Mar. 26 – 31.

GlueX collaboration meeting, Bloomington, May 9-11,20116 Preparations James McIntyre Brendan Pratt Igor Senderovich

GlueX collaboration meeting, Bloomington, May 9-11,20117 Run conditions Beam energy: 3361 MeV Current: 15 nA, 60 nA Collimator: 2.6 mm Radiator: radiation lengths, gold stability – very good collimator DAQ – labview over VNC, no issues prototype DAQ – full CODA install, data rates pushed the limits, dead time 2.5 kHz with event size 4kB (10 MB/s to disk) thanks to Dave Abbott for help with hanging DAQ

GlueX collaboration meeting, Bloomington, May 9-11,20118 Active collimator

GlueX collaboration meeting, Bloomington, May 9-11,20119 Active collimator data inner wedges, horizontal scanouter wedges, horizontal scan  extra peaks are gone, line shapes are now completely normal, analysis underway

GlueX collaboration meeting, Bloomington, May 9-11, Microscope prototype

GlueX collaboration meeting, Bloomington, May 9-11, Microscope prototype placement scan of relative count rate in direction along the tagger magnetic field floor layout under the Hall B tagger

GlueX collaboration meeting, Bloomington, May 9-11, Microscope prototype placement fiber axis as installed ?

GlueX collaboration meeting, Bloomington, May 9-11, Microscope prototype rates 60 nA corresponds to 50 kHz / 2mm energy bin observed rate 2-5 kHz per fiber probably were not perfectly centered along x trigger scintillator counts much faster, per nA, than 5 x summed fiber rate some fraction of rate in trigger counter comes from bg – lots of interactions in fp material upstream some fraction of rate in trigger counter comes from bg – lots of interactions in fp material upstream phototubes on trigger scintillator saturated at around 350 kHz, one worse than the other. phototubes on trigger scintillator saturated at around 350 kHz, one worse than the other. about 1.3 x 10 8 triggers recorded, full 500 ns fADC traces recorded, so analysis does not need to rely on the trigger. about 1.3 x 10 8 triggers recorded, full 500 ns fADC traces recorded, so analysis does not need to rely on the trigger.

GlueX collaboration meeting, Bloomington, May 9-11, Microscope prototype data A B C D E beam’s eye view dispersion direction fiber A1

GlueX collaboration meeting, Bloomington, May 9-11, Microscope prototype data A B C D E beam’s eye view dispersion direction fiber B1

GlueX collaboration meeting, Bloomington, May 9-11, Microscope prototype data A B C D E beam’s eye view dispersion direction fiber C1

GlueX collaboration meeting, Bloomington, May 9-11, Microscope prototype data A B C D E beam’s eye view dispersion direction fiber D1

GlueX collaboration meeting, Bloomington, May 9-11, Microscope prototype data A B C D E beam’s eye view dispersion direction fiber E1

GlueX collaboration meeting, Bloomington, May 9-11, Microscope prototype data A B C D E beam’s eye view dispersion direction fiber sum2 the gains were never matched

GlueX collaboration meeting, Bloomington, May 9-11, Status of analysis and outlook 600 expected mean pixel count ~ 350 x 1.7 = pixels 600 is 400 saturation cuts spectrum off at 1600 pixels, visible in peak asymmetry – see fiber C1 – 600 is 400. ADC peak 1200 nominal design is ~ 2 mV / pixel pedestal(400) + signal(800) = ADC peak 1200 so far, evidence is consistent with expectation so far, evidence is consistent with expectation summed channels difficult to analyze single fiber fADC is 500 mV full scale, 0.5 mV/count using Qsum should be possible to resolve single-pixel pulses,TBD time resolution results yet to come, against beam RF time resolution results yet to come, against beam RF