Event Info Window

The Event Info window gives specific information about the event currently being viewed. The following list describes the meanings of each of the displayed quantities.

NHIT

The total number of electronics channels that fired in the event. If the same channel fired multiple times, then each firing contributes to the total NHIT. In this case, two numbers will be displayed. The first number gives the number of unique channels that fired, and the second number (in brackets) gives the total NHIT. Also, some hits may be hidden due to the settings of the Display menu. In this case an additional number will be shown, indicating the number of hits that are visible of the unique PMT's in the event. For example, a display of "245 of 300 (350)" indicates that there are 245 hits visible of 300 unique PMT's hit, and a total of 350 hits in the event.

The global trigger ID for the event. By default, this is displayed in decimal, but it can be changed to hexadecimal through the GTID's: option in the Settings window. The global trigger ID word is 24 bits, and is designed to uniquely identify an event within a run. However, due to the existence of orphans (GTID = 0) and the possibility of hardware read errors, in practice these numbers are not necessarily sequential or unique within a run.

The CAEN trigger number for this event. Immediately after a cold run start this should be the same as the event GTID, but since the SNO hardward skips GTID's ending in 0xffff, this quickly deviates from the event GTID.

The serial number of this event within the run. This number is generated by the software as an index for the event. When summing events, this entry changes to SUMMED, and represents the total number of events summed together.

The run and sub-run numbers for this event in the form RRRRR_SSS, where RRRRR is the run number and SSS is the sub-run number. As of builder version 3.0.0, these numbers are also valid for dispatched data.

The date of the event in format mm/dd/yyyy taken from the 10 MHz clock of the MTC word, and corrected to Sudbury time, local time, or UTC time depending on the time setting. The date for orphan events will be expressed as 00/00/00.

The time of the event expressed in Sudbury time (EST), local time, or UTC time depending on the time setting in the Settings window. The label reads Time:, Loc Time:, or UTC Time: corresponding to the current time setting. The time is displayed in hours (24 hour clock), minutes and seconds taken from the 10 MHz clock in the MTC word. The seconds are given to a precision of 100 nanoseconds, which is the 10 MHz clock resolution, however, due to rounding errors in double-precision arithmetic, the accuracy of the last few digits is not guaranteed.

The relative time between the current event and the previous and next events loaded by XSNOED. Prev is the time to the previous non-orphan event in the "uncut" history, and Next is the time to the next non-orphan event in the "future" buffer, as measured by the 50 MHz clock. Note that the 50 MHz clock wraps around after 48 hours, so the displayed time is only accurate if the events are closer in time than this.

The trigger bits that were set for the event. For a detail description of the different trigger bits, see the table of valid trigger bit names in the Event Control window section.

The FECD trigger channels that fired. Currently the following FECD's have trigger inputs:

Crate	Card	Channel	Trigger
17	15	17	N20L
17	15	19	N20
17	15	23	GT
17	15	28	N100L
17	15	29	N100M
17	15	31	N100H

TUBII trigger word in hex. The event GTID is also shown in brackets on this line if it is different from the SNO GTID (which may happen in an orphan event for example).

Digitized measurements from the ESUMHi analog trigger. Pk is the measured peak of ESUMHi in a window from about 80 ns before the threshold crossing to 160 ns after. It is fairly low gain, so normal pulses produce a value only a few counts above the pedestal of about 7 counts. Int is the integral of the ESUMHi pulse. It is measured in the same window as the peak, and is fairly high gain so it is likely to rail at 255 for high charge events. It has a pedestal of about 60 counts. Dif is the derivative of ESUMHi at threshold crossing. It is fairly low gain and has a pedestal of 0 counts. All of these are 8 bit unsigned ADC values.

Gives the energy of the event in MeV. The value is obtained from the first QRSP object associated with the displayed event.

The number of normal PMTs in this event. If any PMT is hit more than once, the total number of normal PMT hits is displayed in brackets following the number of unique normal PMTs.

The number of outward looking (OWL) PMTs in this event. If any OWL is hit more than once, the total number of OWL hits is displayed in brackets following the number of unique OWLs.

The number of low gain tubes in this event. If any low gain PMT is hit more than once, the total number of low gain PMT hits is displayed in brackets following the number of unique low gain PMTs.

The number of neck tubes in this event. If any neck tube is hit more than once, the total number of neck tube hits is displayed in brackets following the number of unique neck tubes.

The number of Berkeley Underwater Tube Testing Sled (BUTTS) PMTs in this event. If any BUTTS tube is hit more than once, the total number of BUTTS hits is displayed in brackets following the number of unique BUTTS tubes.

The number of FECD channels that participated in this event. If any FECD is hit more than once, the total number of FECD hits is displayed in brackets following the number of unique FECDs.

The number of NCD shaper channels that fired for this event. The first number is the number of NCD's with shaper hits, and the number in brackets is the total number of times that a shaper fired.

The number of NCD MUX channels that fired for this event. The first number is the number of NCD's with MUX hits, and the number in brackets is the total times that a MUX fired.

The number of NCD's with scope data for this event. The first number is the number of NCD's with scope data, and the number in brackets is the total number of NCD hits with associated scope data.

The number of general NCD records in this event. General NCD records are not associated with a specific tube. They are used to pass additional information about the NCD system. If a general NCD record is present, the NCD Info window will give more information about its contents.