Add a flag in vpdTotCorr.idl for noVPD start calibration switch

In low energy runs, the VPD acceptance and efficiency becomes a potential issue. We are planning to develop a barrel TOF self calibration algorithm based on only the hits on the barrel trays (we call it non-vpd-start calibration). The calibration constant structures should be similar as the conventional calibration using vpd for the start time. But certainly the algorithm in applying these constants will be different. We thus need to introduce an additional flag in the calibration table to tell the offline maker to load the corresponding algorithm then. The proposed the change is on the vpdTotCorr.idl table. The current structure is like this:

struct vpdTotCorr {
  short tubeId;   /* tubeId (1:38), West (1:19), East (20:38) */
  float tot[128]; /* edge of tot intervals for corr */
  float corr[128];   /* absolute corr value */
};
 

We would like to add another short variable "corralgo", then the modified idl file should be like this:

struct vpdTotCorr {
  short tubeId;   /* tubeId (1:38), West (1:19), East (20:38) */
  float tot[128]; /* edge of tot intervals for corr */
  float corr[128];   /* absolute corr value */
  short corralgo;     /* 0 - default vpd-start calibration algorithm */
                             /* 1 - non-vpd-start calibration algorithm */
};
 

We will make the corresponding modifications to the StVpdCalibMaker and StBTofCalibMaker to implement the new calibration algorithm.

 

Proposal of new TOF tables for Run9++ (Jan. 2009)

We are proposing to create several new TOF tables for future full barrel TOF runs.

Draft IDLs:

/* tofINLSCorr
 *
 * Tables: tofINLSCorr
 *
 * description: // INL correction tables information for TOF TDIGs (in short)
 */

struct tofINLSCorr {
  short tdigId;         /*  TDIG board serial number id  */
  short tdcChanId;      /*  tdcId(0:2)*8+chan(0:7)       */
  short INLCorr[1024];  /*  INL correction values        */
};

INDEX: trayCell [ table: trayCellIDs ], range: [1 .. 30000]

Note: This table is an updated one from the previous tofINLCorr. Considering the considerable I/O stream load for this table in future full system, we changed the precision of the correction values from float to short (the value will be stored as (int)(val*100)). From the intial test, we won't lose any electronic resolution.

/* tofGeomAlign
 *
 * Tables: tofGeomAlign
 *
 * description: // tof alignment parameters for trays, trayId will be
 *              // indicated as the elementID (+1) in data base
 */

struct tofGeomAlign {
  float z0;     /* offset in z */
  float x0;     /* offset in radius */
  float phi0;   /* offset in phi (local y direction) */
  float angle0; /* tilt angle in xy plane relative to ideal case */
};

INDEX: trgwin [ table : trgwinIDs ], range : [1..122]

Note: This table contains the necessary geometry alignment parameters for real detector position shifting from the ideal position in GEANT. The trayId will be indicated as the elementID in the database.

/* tofStatus
 *
 * Tables: tofStatus
 *
 * description: // tof status table
 */

struct tofINLCorr {
  unsigned short status[24000];    /*  status code */
};

INDEX: None

Note: TOF status table. The definition of the status code is being finalized.

/* tofTrgWindow
 *
 * Tables: tofTrgWindow
 *
 * description: // tof trigger timestamp window cuts to select physical hits
 */

struct tofTrgWindow {
  unsigned short trgWindow_Min;    /*  trigger time window cuts */       
  unsigned short trgWindow_Max;    /*  trigger time window cuts */
};

INDEX: trgwin [ table: trgwinIDs ], range: [ 1 .. 122 ]

Note: TOF trigger time window cuts to seletect physical hits. There will be 120 (trays) + 2 (E/W Vpds) elements in total.

Load Estimate

tofINLSCorr:  There will be one row for each channel. In total for full barrel system, there will be ~24000 rows. We also have some spare boards, to have all in one place, the maximum # of rows is better to set as 30000. The total load size for DB I/O will be ~30000*1024*2 Byte ~ 60 MB

tofGeomAlign:  There will be 120 rows in each fill. The load size is negligible.

tofStatus:    All channels are combined in a single array.

tofTrgWindow:  120+2 elements.