Tevatron States Device and Clock Events

| Tev State Devices | V:CLDRST  | Tev State diagram | Tev Clock Events |
(Last updated 4/19/00)

Tevatron States Devices

For Collider Run II there are a number of  Tevatron States Devices which are used for Tevatron bookkeeping operations and to communicate Tevatron information other systems such as the LLRF and beam instrumentation.  Other front ends can be notified of changes to these Tevatron state devices through a variety of methods which are described in the help on the application program D88 States Device Manger.

A few example of particular states devices closely related to the Tevatron are listed in the table below.
The states device V:CLDRST is described in more detail in later paragraphs and states devices related to injection are described in more detail in separate documents on the Tevatron Home Page.
 
 
 
States Devices for Tevatron Operations
State Device State Name Examples
V:OPERMD Accel.Operational Mode High Energy Physics
    Maintenance and Repair
    Shutdown
     
V:TEVMOD  Tevatron High-level Mode  Shutdown
    Access
    Collider HEP
    Proton Only Store
     
V:TEVCOL  Global Tev Coll. State Scrape During Store
    Goto Injection or Safe Position 
     
V:CLDRST State of Tev Collider (See paragraphs below)
     
V:NXTBKT  target bkt for next xfer [1 - 1113]
     
V:NBATCH  #bunches for next xfer [1 - 12]
     
V:BKTGAP  buckts between batches 21
     
V:XFER  next Tev transfer number [1-36]
     
V:NXBNCH  leading bnch next xfer [1-36]
     
V:XFRTYP  particle type next xfer Forward Proton
    Forward Pbars
    Reverse Proton
    Reverse Pbars

 


Tevatron State Device (V:CLDRST - State of Tev Collider)

The State of the Tevatron during Collider Run II operations will be broadcast and contained in the ACNET states device V:CLDRST.  Through a variety of methods (see the help on D88 States Device Manger) other front ends can be notified of changes to the Tevatron state. For instance the flying wires front end can get information on the Tevatron state through this method.

For the Tevatron in Collider Run II we have setup the states device to reflect the mode of operation shown in the following state diagram. The arrows show state transitions during a normal shot setup and in almost all cases these transitions are initiated by the collider sequencer. The exception is the transition to the Recovery state which occurs after a quench or if the Tevatron has been turned off. On a quench event ($4E or $5E) an OAC client will set the Tevatron state to Recovery.
 


Tevatron Clock Events

Associated with many of the states are TCLK events which trigger or mark the begining of some action taken during that state. In some cases the Tevatron state is changed by the sequencer before the clock event occurs. For instance the Tevatron state will be set to Squeeze before the $C5 event occurs. This allows other front ends, upon notification of the state transition, to be prepared for the $C5 event. These clock events are listed in the Table below. For an image of the Tevatron Shot Setup Timeline with clock events click here.

Note: Clock event $67, $69, and $6C have not yet been assinged. Nor have the descriptions of all clock events on T61 been updated to reflect their use for Collider Run II.
 
 
Clock Events Associated with Tevatron States
State number
State description
Clock Events
1
 Proton Injection Porch Event $43 (Start of Tevatron fron porch.)
2
 Proton Injection tune up Event $2B+$4D; $5C is echo of MIBS 7C
3
 Eject Protons Event $2A+$5D; $55 is echo of MIBS D8  (Reverse injection.)
4
 Inject Protons Event $2B+$4D; $5C is echo of MIBS 7C
5
 Pbar Injection Porch Event $C3 (Opens injection helix.)
6
 Inject Pbars Event $2A + $40; $5B is echo of MIBS 7B 
7
 Cogging -
8
 Before Ramp Event $C4 (Increments LBMDAT and removes injection orbit bump.)
Event $C2 (Marks Before Ramp state.)
9
 Acceleration Event $42; preceded by $63  (Start of the Tevatron ramp.)
10
 Flattop Event $45; followed by $62  (Start of Tevatron flattop.)
11
 Squeeze Event $C5 (Starts the Low Beta Squeeze)
Event $C4 (Increments LBMDAT and advances squeeze one step.
                   Used during a parse or luminosity leveling.)
12
 Initiate Collisions Event $C6 (Increases chromaticity and removes separator 2-bumps.)
13
 Remove Halo - (Leave option open for new event)
-
 Smooth during store Event $61 (Smooth orbit during accelerate/squeeze)
Event $67 (Smooth orbit during decelarate/unsqueeze)
14
 HEP Event $CB (Marks beginning of HEP)
Event $CE (Marks end of HEP)
15
 Pause HEP - (This state used for studies/tune up with stored beam.)
16
 Proton Removal Event $69 (Start proton removal. Starts ramp for chromaticity, separator 2-bumps, and dogleg magnets.)
Event $6C - (After proton removal. Starts ramp turning off dogleg and ramping separators to zero.)
17
 Unsqueeze Event $C9 (Starts Low Beta Unsqueeze.)
Event $C7 (Decrements LBMDAT and decreases squeeze one step.
                   Used during a parse or luminosity leveling.)
18
 Flattop2 - (Leave option open for new event)
19
 Deceleration Event $6D; preceded by $63 (Start of Tevatron down ramp.)
-
 Deceleration (without squeeze) Event $6E; preceded by $63  (Start of Tevatron down ramp when no low beta squeeze was done.) (Not implemented yet.)
20
 Extraction Porch Event $44; followed by $62 (Start of Tevatron back porch.)
21
 Extract Pbars (Events $20+$54; $5F is echo of MIBS D6)
These events depend on pbar recycling and may change!
22
 Reset Event $41 (Tevatron ramp reset.)
23
 Recovery -
24
 Ramping -